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Posted By: SatKartr XPA 2 Now! A Keeper? - 10/25/08 05:05 AM
Well I was sort of underwhelmed with the XPA 2 for the first day and a half watching/listening to compressed Directv HD and 1 or 2 poorly recorded CDs but then tonight I bought the bluray Hulk and Wow! What a mind blower! I was totally sold. It's funny too, you know my best friend who watched Iron Man and Hulk (multiple times with his son?) in the theater thought Iron Man was better and Rotten Tomatoes gives Iron Man a 93% and Hulk only a 67% approval rating but it made perfect sense after tonight why a number of posters here liked the Hulk better, the Hulk soundtrack is so much more engaging/fulfilling to my ear from an audio sensory perspective.

Here's the problem--the XPA 2 kept going into protect mode, not for sudden loud sounds but whenever there was a crescendo.

Problem #2: I think I might have messed up one of the inputs when I was unpacking the amp to keep from dropping it, I'm afraid 87 lbs (?, or whatever) is a bit unwieldy and that would be my main critique of the amp so far; as I get even older with even more back issues I would/will need a maintenance crew to move things around; hmmm, I wonder how I am going to the muscle the ep800 into position, I have wood floors doncha know and sliding things is an issue, of course we have felt pads glued onto the bottoms of all furniture, is that just as good sonically as the rubber feet on all this "audiophile" equipment (axiom, emotiva)?

So far on the Emotiva lounge the XPA5 has been causing red light of death issues for random folks and it's been blamed on cabling (something I need to experiment with) but no one has had trouble with the XPA2 so maybe the damaged RCA input is my problem. I can experiment with cable connections as well, is there such a thing as an RCA/unbalanced to balanced input adapter? Maybe if I avoid the busted RCA input I will be OK--I have questions though: at first the red lights were all on the left side, which is the side with the loose input, then they shifted to the right side, in which the input is OK. There is zero noise at any volume, so there is nothing so crude as that going wrong.

Also reading the Gene Dela Salla article where he was having trouble in some sort of test mode (?) when sweeping from high to low (20k to 20hz) but not on stereo playback, and it seems to me that he may not have tested the amp that much for HT (?) as opposed to music, might that correspond to the shut down on crescendo issue I am having, given that HT tends to boom out the lows increasingly during exciting sequences? More or less a random thought, but I had to wonder why the impact of sheer volume did not seem to trigger a protection/default shutdown by shaking something loose, if power alone was the issue.

Of course this has all been so exciting that I keep listening to the movie at high volumes and haven't even been annoyed by the frustrating interruptions, I would even like to keep the amp if I can work through the problems, isn't that always the way, things go wrong on Friday evening, just as soon as there's no one to call?

Well if any one has any info re: emotiva protection issues that would be cool, but as a disclaimer I must point out that since the input appears to have been damaged and no one else has reported the issue for the xpa 2 the positives I am experiencing may stand and the negatives may be irrelevant and hopefully will be resolved . . .
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/25/08 05:49 AM
Wow, why does this not suprise me. I'm sorry for your problems. Over a year ago I had similar issues with the "king of the hill" MPS1. Driving two m80's it kept shutting down. Emotiva would send me new amps to put in the chassis, and guess what, they would shut down. They wanted me to cut some limiter circuit off the boards to bypass this protection. I think not, after 3 months of screwing around, they graciously let me return them for a full refund. Sure sounds familiar.

Have been driving my 80's with Odyssey Audio monoblocks ever since with no issues. And just to let you know, my Denon 2805 would reach much higher levels with no clipping before the MPS-1 would say goodnight.

I also would like to mention, I was not listening to what I call very loud levels. Even during explosions in movies, they would shut down.

My guess is that your using 80s?
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 06:17 AM
I was afraid you were going to say that, I knew you had problems with the MPS-1, so much for the "new architecture" perhaps, maybe it's just the same limiter circuit.

What I keep wondering though is since I have changed so many variables at once it's become pretty hard for me to trouble shoot even conceptually what may be going wrong. It seems to me now since last post from observing/listening the rest of the movie that it may only be when the LFEs kick in that the amp shuts down, is it possible that when I am running a sub and have a crossover set to spare the M80s and/or with M80s are set to small that the problem will abate? I could test those variables now and of course I will but it makes me wonder. I still don't understand how the protection circuits work, are they sensitive to the situation in which the speaker is not able to handle the power X frequency equation, e.g., high power X LFE beyond speaker capacity blow out the woofer time?
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/25/08 06:24 AM
I think the issue lies with the interaction of the M80s/emotiva protect circuit, so to speak. The M80s impedence may dip too low at a certain frequency thus causing the Emotiva to shut down, which makes me think Emotiva is a little too protective with their circuit, as there are many receivers that do not shut down with the M80s.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 06:38 AM
Hmm thanks for the feedback, that makes sense, if you are right it may be a death knell for the combo of the XPA2 and M80s, funny though because a number of people are running the XPA5 without problem I believe some folks with the M80s, maybe just the M60s. I was hoping the difference in electronics between the XPA and MPS series was the culprit, the irony to me initially with all this was that the MPS1 has lower maximum output than the M80s are rated, I was hoping that the issue had more to do with a quirk with the MPS amp, perhaps not. The other monkey wrench is the fact that the emotiva folks state that the xpa2 is "a whole 'nother level" than the xpa3 or xpa5 architecture, perhaps the new level includes the protection circuit from an earlier (mps) level.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/25/08 06:52 AM
Sat, the Emotiva may be a mystery to me, but in general protective circuits take effect either because of too much heat(unlikely in your case)or too much current. LFE occasionally appearing during movies does require more current, but even well-designed receivers(e.g., Randy's 2805)should be able to handle this at reasonably loud levels. Yes, taking some of the load off with a "small" setting and probably a 80Hz crossover for the M80s should help, but it's disappointing if the amplifier needs the help.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 07:44 AM
OK thanks, that helps me better understand the basis of the problem, Dela Salla recommends having a dedicated 20 amp line to support this amp but I'm not sure even that would help, e.g., I just unplugged the amp from the power conditioner and plugged the amp into the wall (emotiva recommends plugging the xpa2 directly into the wall, presumably to draw current without obstruction) yet playing the same content the amp seems even more volatile, as if it is drawing even more power, which appears to trigger the protection circuit even more easily in response to a spike in power given dynamic HT content.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/25/08 08:38 AM
Must be time to try the A1400 for at least one set of M80's \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 09:01 AM
Wish I had the dough, that's why I've been trying to take the low road. ;\)
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/25/08 09:05 AM
Low road? I must be in the tunnel under it \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 09:19 AM
So I plugged the amplifier back into the power conditioner and have been watching the amperage drawn, the protection circuit on the emotiva reliably kicks in once the measured amperage goes above 13 amps for the entire HT system (i.e., once it measures 13.3--13.8, inaudible BOOM!), the house was built in 1989 (we moved here from an apt in 2005, yay!) and I suspect it's underpowered from past experience with the AC going out, I seem to remember most of the power lines in our home other than the wiring for 1 or 2 major appliances being rated at a maximum of 10 amps, I'm thinking an electrician might be able to help, especially given that I'm anticipating an EP800 on or about 11/17, I could be looking at trouble if I fail to upgrade the power lines, why does it never end (ah, what would I find to do if the project ever ended? ).

Perhaps the M80s are thirsty and the home wiring can't keep up!? \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 09:36 AM
Good one! \:D I wished I lived in Canada, I loved those days when I still lived in the Northeast and cherished nature over what has always seemed to me an insane form of urban accomplishment (you move to the city for the wife, no?). Now the "sweet spot" to me signifies going totally over the top to future proof and avoid buyer's remorse without leaving me destitute. Bring me back to that lake (Dunmore?) in Vermont any day . . .

I guess when you compare $800 to $3850 the emotiva still is a good deal, if I had the cash I would have pulled the trigger on the A1400 and put myself out of this misery long ago . . .

If I were a rich man . . .
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/25/08 12:12 PM
Reading these recent posts on amp/power issues, I guess I should be happy my HT is in a small room and don't need the extra power.
Posted By: MarkSJohnson Re: XPA 2 Now! A Keeper? - 10/25/08 01:28 PM
Maybe it can be returned for a few Outlaw Monoblocks or their 5 channel amp. I never hear of problems with them....
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/25/08 01:39 PM

The M80s are a fairly easy 4 ohm load. Any amp that couldn't handle the M80s wouldn't be on my list for sure.


Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/25/08 01:54 PM
Hey Rick. Where is that graph from. I want it as a reference the next time some joker posts on audioholics that the M80 is a 2ohm speaker.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/25/08 02:09 PM

Ya know what Fred, Ive had that graph for so long I don't remember where I got it. Just copy it from my post and save it.

Come to think of it I believe Ian did a post here some time ago with a slew of different graphs, that's where it come from.................I think.
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/25/08 02:19 PM
Sigh, I thought I would try the lazy man's way first. I guess if I park it in my online photo collection it will be hard to loose.
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/25/08 02:20 PM
Hi Fred,

That graph is from the National Research Council lab in Ottawa, where Soundstage.com does many of its speaker measurements. If you go to Soundstage.com and then access their measurements, you can scroll down to the impedance vs. frequency charts for lots of speakers they've tested, including the M80s.

Yes, the Emotiva amps do have issues with low impedance high-current loads, as do some other manufacturers. Often a two-channel amp will do much better than a multi-channel amp, largely because the multichannel versions can't handle the heat issues. One Axiom owner had five M80s and went through a number of multichannel amplifiers, all of which would shut down driving the five M80s to extremely loud levels (those were Outlaw and Parasound multichannel amps). He settled on a two-channel amp for the mains and a separate three-channel amp, if memory serves.

Regards,
Alan
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/25/08 02:28 PM
My memory sucks \:\) Alan is right...................I think \:D
Posted By: RickF Re: XPA 2 Now! A Keeper? - 10/25/08 02:30 PM
With tiled or marbled floors throughout ... ouch!
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/25/08 02:30 PM
 Quote:
where Soundstage.com does

<-- Smacks forehead.

Thanks Alan. I've only been to the soundstage.com site a few thousand times. It seems to have the most comprehensive collection of anechoic measurements around.
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/25/08 02:35 PM
It's a complicated site to navigate. It always takes me forever to find the measurements page. I'll post the link if I figure it out. . .
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/25/08 02:42 PM
Hi,

OK, here's the link to the M80 v2 measurements and impedance curve:

http://www.soundstagenetwork.com/measurements/axiom_m80v2/

If you just go to http://www.soundstagenetwork.com/measurements you can access all the NRC speaker graphs for speakers that Soundstage has measured at the NRC.

Regards,
Alan
Posted By: terzaghi Re: XPA 2 Now! A Keeper? - 10/25/08 02:44 PM
wow... I was really thinking it would be good to buy one of these XPA2's also. And to think audioholics gave it such a rave review... hmmmmm.

oh well, I need to buy an ep-800 first anyway... and a diamond ring before that.
Posted By: Lorenzo1000 Re: XPA 2 Now! A Keeper? - 10/25/08 04:04 PM
The other alternative is to look for a good used amp on Audiogon.

You can usually find good deals on Acurus (A250 or A200X3) or ATI
AMPS there. I've had both brands and they never shut down on me.
Posted By: Ken.C Re: XPA 2 Now! A Keeper? - 10/25/08 04:40 PM
Actually, he used 4 2 channel Parasound Halos. Of course, he was regularly driving them to 115 dB+
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/25/08 04:47 PM
Thanks, Ken.

You actually experienced his setup and the 115-dB-plus SPLs, right? I had running communications with Denis as he went through various combinations of multichannel amplifiers.

Alan
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/25/08 04:58 PM
It is intresting to look at the different measurements. The M22 which no one appears to ever have an issue driving, has a pronounced dip to 2 ohms, so much for my theory.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/25/08 05:21 PM
Does the high-current-draw-shutting-down-the-amplifier problem have anything to do with the fact that the electrical wiring in my home I'm pretty sure is not rated to handle the current being drawn? If I upgrade the wiring to 1 or 2 dedicated 20 amp lines, might that solve the problem? It doesn't make sense to me that it would except through some kind of instability phenomenon, e.g., when I plug the amp directly into the wall and presumably even more power is available it almost seems to cut out faster. I may need to upgrade the wiring anyway given the load I am already running and what with the ep800 on the way, but I was just wondering if there was any theoretical reason to expect that it might help.
Posted By: Ken.C Re: XPA 2 Now! A Keeper? - 10/25/08 06:02 PM
I would think that by law, if an amp required more than a 15 amp outlet could put out, it would have a 20 amp plug. AFAIK, this one does not. Sounds more like a design flaw to me than a problem with your house wiring.

Alan, I don't think we ever took it to 115dB when I was there--I'm pretty sure we topped out at 105, and that was quite loud enough for me.
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/25/08 06:39 PM
SatKartr,

I don't think the wiring in your home would have any influence on the performance of the amplifier cutting out, unless the circuit into which you had the amplifier plugged was clearly overstressed--you'd have indications of that with lights on the same circuit dimming on peaks if thr circuit was overloaded or inadeequate.

Alan
Posted By: Ken.C Re: XPA 2 Now! A Keeper? - 10/25/08 06:40 PM
Oh, you mean like what happens when my laser printer prints something? ;\)
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/25/08 11:53 PM
This is more or less unrelated to the conversation at hand, but I wanted to comment again on how nice it is that people like Alan from Axiom actively participate in these discussions, even when discussing problems that Axiom customers are having with non-Axiom products. It definitely keeps me coming back as I find that I'm always learning new things as I peruse the forums. <group hug over> \:\)

Jason
Posted By: turbo16v Re: XPA 2 Now! A Keeper? - 10/26/08 01:04 AM
It sucks when one person has a problem with somthing that a hundred people before didn't and it turns people off. I have said this before and will say it again. my mmc1 and xpa5 are wonderful at running my m80,vp150, and qs8's. I have never had a problem with anything from emotiva. The louder I turn it up the better the m80's sound and the xpa5 seems to never run out of juice. As soon as the xmc1,cd player and dual subs are on the market they will probably end up in my living room. \:\)
I have been thinking about the ep350 and ep500 for a few years now but the thought of duals at 999.00 that come with a cool seperate amp and auto room correction. seems like a dream. maybe it is... only time will tell, I just have to wait for a audioholics.com review. To sum it up i think axiom and emotiva are both great companys that bring great products to consumers at amazing prices. They also stand behind their stuff and have great customer service.... Thanks
Posted By: Ken.C Re: XPA 2 Now! A Keeper? - 10/26/08 01:22 AM
You are correct, of course, Turbo... I shouldn't have said design flaw, I should have said issue with this particular unit.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/26/08 02:57 AM
It was not my goal to turn people off, merely to find answers, by posting here on the board I have learned that high current appears to be the trigger for the unit going into protect. I haven't given up on the xpa 2 yet and plan to contact emotiva early next week. No one on the emotiva lounge has responded to my query suggesting it seems to be an unusual problem with regard to the xpa2, and could in fact be a fluke.

Alan states that a number of amps, not just emotiva, have not paired well with the m80s so it is also an Axiom issue to understand just what type of amp works well with the m80s. The xpa2 is supposed to be "completely stable into 4 ohms" and with the power rating it is hard to understand what the problem could be. Perhaps it is coincidental or something unique to my setup, time may bring answers or not, I will let you all know what happens.

With a 30 day risk free trial I think it was worth it to check out the amp and it is quite an amazing piece of electronics, I'm still hoping the issue can be resolved. Hopefully Lonnie will extend the trial period if necessary as he did for Randy to give me a chance to solve the mystery. Turbo I'm glad you spoke up as you did before, people need to know that emotiva can work well together with axioms, especially since you are running the m80s. I was tempted by the dual subs as well, the price/value equation is just amazing with emotiva!
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/26/08 03:19 AM
If I had the money I would buy an XPA2 just to see if I get the same results as you or I could get lucky and have no issues and one very cool amp, but Christmas is coming and the wallet is very dry at the moment.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/26/08 03:27 AM
If the wallet is dry, may we infer you've made a significant non-audio purchase you've been hinting about for some time now? \:D

Jason
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/26/08 03:31 AM
 Originally Posted By: myrison
If the wallet is dry, may we infer you've made a significant non-audio purchase you've been hinting about for some time now? \:D

Jason
Non-audio purchase, you sure that was me? I am still recovering from too much summer spending on my new patio and some work out on my parents property.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/26/08 03:38 AM
Sorry about that... it's late and clearly I need to go to bed... I was thinking of David (Terzaghi) and his continued hints that if he buys more speakers before buying a ring there will be serious hell to pay.

Definitely time for bed!

Jason
Posted By: merchman Re: XPA 2 Now! A Keeper? - 10/26/08 03:43 AM
Too much time in the room of death coupled with lot's of speakers and a cool named amplifier, and all the other fun toys. \:D Get some rest.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/26/08 06:21 AM
 Originally Posted By: myrison
Sorry about that... it's late and clearly I need to go to bed... I was thinking of David (Terzaghi) and his continued hints that if he buys more speakers before buying a ring there will be serious hell to pay.

Definitely time for bed!

Jason
I thought maybe my wife had me posting something in my sleep just so she could say she had witnesses!
Posted By: Ya_basta Re: XPA 2 Now! A Keeper? - 10/26/08 12:08 PM
When I was having problems with my RPA-1, Emotiva told me that they have run tests with M80s and they can dip to 2 ohms.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/26/08 12:40 PM
 Originally Posted By: wheelz999
When I was having problems with my RPA-1, Emotiva told me that they have run tests with M80s and they can dip to 2 ohms.


If this is the case I would like to see an updated impedance graph from Axiom. The one I posted shows they dip nowhere near the 2 ohm mark.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/26/08 02:01 PM
That is interesting. When I was having issues a year or so ago, Emotiva had never heard of Axiom. There was also a guy with 4ohm Rocket bookshelfs shutting down his mps1.

Here is my long post, near the end you'll find MadScientist, that is Lonnis from Emotiva adding in to the conversation.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=162446&fpart=1
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/26/08 02:23 PM
Hi SatKartr,

When I said ". . .that a number of amps, not just emotiva, have not paired well with the m80s" and you replied "so it is also an Axiom issue to understand just what type of amp works well with the m80s", I want to clarify my comments.

It is only under extreme conditions, such as the SPL levels that you are trying to reach, SatKartr, as well as some other Axiom M80 owners (sometimes multiple M80s) that some separate power amplifiers, Emotiva included, shut down or overheat. For the vast majority of users, the Emotiva, Parasound and Outlaw amplifiers will drive the M80s without problems.

It all comes down to a matter of current flow through the output devices at extremely high sound pressure levels, and the ability of the amplifier's heat sinks and/or fans to dissipate the heat generated by lower impedances. The M80 is "nominallly" a 4-ohm speaker and does not dip below 4 ohms anywhere over the audio spectrum.

In terms of heat dissipation and high SPL levels, prior to the development of Axiom's A1400-8, there was a memorable party at Ian Colquhoun's home. At the time he was running five Denon monoblocs at 350 watts per channel into the M80s, dual VP150s and five QS8s, plus two subs, an EP600 and an EP500. At one point in the party, the level controls advanced farther and three of the five Denons shut down. I was using earplugs all evening and even with the ear plugs I retreated into the woods outside Ian's house! The SPLs were deafening. That evening was the genesis for developing the A1400-8, as Ian had grown tired of the Denons shutting down at extremely high listening levels.

I'd also point out that there is no substitute for expensive output devices that can handle very high current flow into lower impedances without overheating. That's what we use in the Axiom A1400-8 and that's also why the amplifier is relatively expensive. In order to reach a particular price point, other manufacturers may choose devices that are much less costly and will be fine in most playback situations for most listeners--but not all.

Regards,

Alan
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/26/08 06:26 PM
Thanks Alan for the clarification, sorry if I misconstrued your comments.

That party does sound very memorable! Ian must be quite over the top.

I'm not sure the amp is overheating though. I picked up an spl meter and am measuring 90-100 dbls in HT (doesn't happen with music at this spl) when the protection fault kicks in, which can happen within a minute or so of initiating a movie (e.g., the intro to Hulk).

Thank you everyone, I appreciate your help and efforts to increase my knowledgeability, at this point it clearly seems to be an Emotiva issue so I will pursue it via their tech support, and of course will let you all know if there are any solutions found.
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/26/08 10:10 PM
Hmm. Is 90-100db for short periods of time considered extreme?
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/26/08 10:15 PM
 Originally Posted By: fredk
Hmm. Is 90-100db for short periods of time considered extreme?


I'd say not, my Rotel can do that for long periods of time and only get warm to the touch.
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/26/08 10:34 PM
Thats what I thought. It sure seems like a defective unit.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/26/08 11:22 PM
Well let's don't forget I inadvertently smashed one of the inputs before plug in so the jury is still out . . . \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/26/08 11:53 PM
BTW the most poignant aspect about your post to me was the anecdote about retreating to the woods in the middle of Ian's party. OMG I miss Vermont, I used to love serene nature as a backdrop every day and took it so much for granted!

At least Dallas squeaked out a win today so I won't be living in Mudville tomorrow .
Posted By: alan Re: XPA 2 Now! A Keeper? - 10/27/08 01:55 PM
Yup, I agree having serene nature as a backdrop every day is really beautiful, and northern Ontario where Axiom is located is very calming. But I can't take the brutal winter and relative isolation up there for long periods of time.

I love my visits to Axiom but after 10 days or so I need the hit of the city and urban life.

Regards,
Alan
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/27/08 02:55 PM
I'll be curious to hear what Emotiva has to say about this. They're probably getting tired of Axiom owners breaking their amps. ;\) Not sure what these sorts of posts say about their designs though...

I agree with the others. I don't think it's your home wiring. If you're pulling too many amps, I'd think you'd see lights flickering or you'd start flipping breakers. Although would it be possible to pull enough amps that you'd start to affect the voltage? I am NOT an electical engineer - so someone please correct me, but aren't volts and amps related? Could an amplifier go into shutdown mode if it was pulling so many amps that the voltage dropped too much?

For the record, I've never had any problems with my cheap LPA-1 driving my whole system, which includes M80's. I can turn the volume up far past the point where it hurts my ears. No problems at all.


Posted By: alan Re: XPA 2 Now! A Keeper? - 10/27/08 07:31 PM
Hi Peter,

Yep, volts and amperes are certainly related. I'm not an electrical engineer either, but in theory if there is a voltage sag in a circuit, it would seem feasible that overly aggressive protection circuitry might shut down an amplifier.

Protection circuits can monitor any combination of current flow, voltage and thermal factors, so depending on their implementation, they may react quite differently from one brand or model to another.

JohnK may weigh in here at some point. I'll also check with Tom Cumberand, Axiom's R&D "conehead" (as he refers to himself) who is an electrical engineer and an amplifier designer of long experience.

Regards,
Alan
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/27/08 07:59 PM
I wonder how much the voltage would have to sag, I seem to remember the volts ranging between 119 and 122 at least according to my meter, probably closer to 119 when the amperage jumped up, I'll have to watch for that, but there did not seem to be much of a significant dip.

Lonnie asked me to try different cables as a diagnostic.

I changed the interconnects, same problem.

I switched speakers to Polk Reference 10bs and the speakers began to pop, crackle, and fry but the amp did not go into protect.

I used the speaker cables that were connected to the Polks to connect the axioms to the xpa 2 and problem recurred.
Posted By: Hansang Re: XPA 2 Now! A Keeper? - 10/27/08 08:32 PM
It's sad that I've forgotten pretty much everything I learned in my circuit analysis I&II courses. Sad.....
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/27/08 09:36 PM
Here's where it stands, look like I may be at a deadend:

Today at 1:52pm, satkartr wrote:
I changed the interconnects, same problem.

I switched speakers to Polk Reference 10bs and the speakers began to pop, crackle, and fry but the amp did not go into protect.

I used the speaker cables that were connected to the Polks to connect the axioms to the xpa 2 and problem recurred.

One other issue: the left unbalanced input to the xpa2 seems loose, kind of droops downward, I think this may have become damaged when I first wrestled the amp out of the box, however I'm not sure this is relevant in that there is no hum or noise at any volume and I have tried running the right channel only and it still goes into protect.


Lonnie responded:

Looks like you found the root cause of the problem. If the amp does not go into protect with different speakers on it, but does when you connect the Axioms. Ipso-facto the Axioms are the cause. Now I don't know if a particular driver is bottoming out and shorting or if the crossover networks have an overlap with an impedance dip or perhaps the crossovers are just heating up and the parts are changing value, but something in the speakers is the cause and I would contact Axiom and see what they say
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/27/08 09:46 PM
In my tests, the MPS-1 would not shut down when cranking up my Qs8's (6ohm) to the same level as the 80's (4ohm). Emotiva also blammed the Axiom 80's as being the problem. However, others with Rocket 4ohm floorstanders and bookshelfs had the same problem. Back then I think the amp was not able to drive 4ohm speakers, even though the Axiom's don't fall below 4ohm.

Not sure about this new design.
Posted By: tomtuttle Re: XPA 2 Now! A Keeper? - 10/27/08 10:01 PM
Get some M60's.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/27/08 10:58 PM

This is just me but if I were in the very same situation I would send the damn thing back and look else where. It's so easy to blame another product and not look into the actual cause of the problem.

I bet a $300 H/K 2 channel receiver would push those M80s just fine.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/27/08 11:19 PM
I am leaning that way, especially as those comments seemed pretty nonresponsive, I may play with the crossover setting first to see if I would have the same problem once I'm running a full 7.1 system, but I'm not sure what the point would be, if the amp can't be counted on to deliver.
Posted By: RickF Re: XPA 2 Now! A Keeper? - 10/27/08 11:23 PM
 Originally Posted By: wid

I bet a $300 H/K 2 channel receiver would push those M80s just fine.


Although I use a 2 ch Rotel 200 watt amp for the 80s with an H/K 75 watt AVR635 running everything else in the past I have had the H/K running the 80s to pretty darn loud levels for fairly long periods of time without a hitch and for the past year or so it has been running an 8 ohm VP100 parrelled with a 6 ohm VP150 (3.45 ohms) perfectly fine.

I know a Rotel amp will run those 80s easily.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/27/08 11:26 PM
 Quote:

I know a Rotel amp will run those 80s easily.


You got that right BrotherBob
Posted By: RickF Re: XPA 2 Now! A Keeper? - 10/27/08 11:30 PM
I was going to add "Ain't that right Rick", but I didn't want folks to think I was talking to myself ... again.

\:\)
Posted By: Spoiler Re: XPA 2 Now! A Keeper? - 10/27/08 11:36 PM
I can also vouch for the Outlaw Monoblocks. I can run 115 - 120 db's for as long as I can stand in the house...for about 40 min. after a few beers. \:\) I've only done this a few times folks...mostly around the time I got the amps to see how far I could push them.

The amps got toasty... but no shut downs with the M80's. Alot cleaner than the 3805 alone at high levels. I wouldn't consider an upgrade unless Axiom comes out with a 2-channel version (or 3) of the A1400-8.


Posted By: RickF Re: XPA 2 Now! A Keeper? - 10/27/08 11:43 PM
 Originally Posted By: Spoiler
I can run 115 - 120 db's for as long as I can stand in the house...for about 40 min. after a few beers. \:\) I've only done this a few times folks...mostly around the time I got the amps to see how far I could push them.


Was the blood running out of your ears the first sign that the music *might* be a wee bit loud? \:D

I believe anything Outlaw will run the 80s with no problems.
Posted By: Spoiler Re: XPA 2 Now! A Keeper? - 10/27/08 11:49 PM
 Quote:
Was the blood running out of your ears the first sign that the music *might* be a wee bit loud? \:D


I couldn't sit in front of them the whole time. I live alone, so I also roamed around house while enjoying the music. Beer makes you brave...


Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/27/08 11:49 PM
SatKartr,

That's a pretty disappointing response from them... you can turn their logic around on them and tell them that if the Axioms DO NOT shut down your AVR when connected directly, but do shut down when connected to the Emotiva, "ipso-facto the Axioms are not the cause, the amp is!" (but maybe I'm just a smart a$$ and would enjoy writing them an e-mail like that after their sub-par effort to assess the problem...)

Jason
Posted By: Spoiler Re: XPA 2 Now! A Keeper? - 10/28/08 12:03 AM

SatKartr,

You shouldn't have to be fooling with crossover settings to see if it helps at this point. That beefy amp you have should Not be shutting down. My advice is to look into getting a replacement, so you'll know for sure whether you've got a bum amp.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/28/08 12:04 AM
That's the next test actually and your logic actually makes perfect sense. I'm curious to see what kind of SPLs I can get out of the Yamaha, I just picked it up as a bookmark until I can decide exactly what pre/pro I want to go with.

I suspect maybe Lonnie is acting so lackadaisical since he went through all of this with Randy and the MPS-1 so now he may have a defeatist attitude regarding the M80s. It also seems funny because the MPS-1 is rated at 300 wpc into 4 ohms versus the xpa2 with 500 wpc into 4 ohms, so I wonder how the protect circuit works such that I can't even generate 90-100 dbls during HT, that surprises me.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/28/08 02:11 AM
I'll be interested to hear what you think about how the Yammy drives them. Please let us know.

By the way, is the family back yet or are you still off the leash? ;\)

Jason
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/28/08 02:16 AM
They arrived a few hours ago, so the leash is back, well I suppose someone has to keep me in line.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/28/08 02:59 AM
Well Sat, as I commented before, the Emotiva remains a mystery to me. There were all sorts of discussions of measurement procedures both on the board and in PMs when Randy was investigating the problem. The resulting numbers weren't anything that should shut down even the typical modestly-priced receiver rated in the 100 watt area.

Protection circuits(besides eventually operating when the temperature would get too high)first operate when the measured current is out of line with the voltage being supplied at the time. One form of Ohm's Law is I=E/R, and if the measured current is some big number in relation to the voltage, that can only be because the resistance has become very low(i.e., a short somewhere in the wiring), and the circuits will immediately shut things down. Power supply sections are limited as to the maximum voltage that they can supply, and since power is the product of voltage times current, if not enough voltage is available for a given amount of power the current would have to increase so that the power equation is satisfied. This increased current measurement again would cause the protective circuits to shut down.

How all this seems to be a problem with the Emotiva/M80 combination at not extremely high sound levels remains unclear. I would be inclined to view the shut-downs as simply being God's way of telling you not to use that amplifier.
Posted By: St_PatGuy Re: XPA 2 Now! A Keeper? - 10/28/08 03:08 AM
 Quote:
I would be inclined to view the shut-downs as simply being God's way of telling you not to use that amplifier.


I have a feeling this chapter is removed from most electrical engineering textbooks. . .
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/28/08 03:33 AM
I think I'm beginning to hear the Big Guy loud and clear. \:D

What surprised me about all this was that Randy had problems with the MPS-1 but others with the RPA and XPA architecture have not had problems pairing the M80s with Emotiva.

Your post has piqued my curiosity though, you state, "if the measured current is some big number in relation to the voltage," are there any standard examples of what a large amperage would be or is it all relative? It seems like the amplifier is going into protect when the current goes up to around 6 amps above baseline (it shuts down when amperage reaches 10-13 amps for all devices connected to the HT electrical circuit with 4-6 amps being the reading when the HT system is on but idling), that level does not seem that extreme to me, but I have no sense of what might be the normal rage.

I was hoping for a long term solution, i.e., headroom for any conceivable situation including even if we moved and our HT was in a bigger space, looks like it's time to search for a Plan B.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/28/08 04:05 AM
If I recall, Lonnie told me the MPS-1 had a "waveform limiter" circuit that was protecting the amp. I don't believe the other amps, or current designs have this circuit, not sure.

Lonnie provided great support and customer service during the 3 months I tried the amp. However, I just could not grasp the feedback saying it was the 80's, or I was driving the amp to its design limits. The 80's are very easy to drive, efficient speakers, that don't fall below 4ohms across the FR.

Something just was not right in my case where an amp with seperate monoblocks with those specs should even flinch. Now the Denon did show some signs of a clipping at +10 to +15 but never shut down. The MPS-1 sounded fantastic with no hint of clipping at all, however it would just shut off for no apparant reason.

My current Odyssey monoblocks (based on German Symphonic Line engineering) A/AB just keep going and going an going. \:\)
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/28/08 01:49 PM
Sat, when you're rocking out on the XPA-2, at the point it's cutting out, what are the status LED meters doing? Are they pegged at the far the ends of the scale? I'm just curious if you can tell that the amp is being stressed (pegged-meters) or if it's cutting out early.

For the EE guys, is there any way that Sat could hook up an ohm meter to his system to monitor the resistance when the XPA cuts out? It seems that would answer the whole question. <4ohm = M80 problem, >= 4ohm = XPA problem.

The bizarre thing here is that the folks at Emotiva can build an amp that works. They know how to do it. As I've said, I have no problems with my LPA-1 + M80 combo at these 100db+ 'reference' levels we're talking about. None at all. And there are several others around here with the same setup. And the LPA-1 is/was their cheap amp.

But it makes no sense to me that their flagship multichannel MPS-1 and their top-end stereo XPA-2 can't drive M80's. It was absurd when Randy went through this, and it's still absurd that Sat is having the same problem. Since Emotiva claims the M80's are the problem, I'd love to see that data. They need to explain *why* the M80's seem to break some of their amps.

But from a troubleshooting perspective, I can see where Lonnie is coming from. It's still not the best response but I understand it. Since you changed speakers (were the Polks 4-ohm too?) and the XPA worked, then that points to the "problem" being the M80's. That "problem" is easily solved by getting your money back for the XPA and getting a different amp. ;\)

Either we're discovering that some M80's have an unusual impedance dip that's too much for their amps, or we're finding that some Emotiva amps aren't meeting their published specs with respect to 4-ohm speakers.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/28/08 02:41 PM
Thanks for the ideas, I will check out the LED thing, the amp is sort of off to the side and turned sideways so I have not monitored what the leds are doing when the amp cuts out, I will obviously have to do that (smacks forehead).

I did email Lonnie back yesterday that the speaker comparison was inaccurate because the Polks are 6 ohm speakers, he has not responded back yet.

The ohm meter idea also sounds promising if there's some practical way to hook it up, I will look into it.
Posted By: tomtuttle Re: XPA 2 Now! A Keeper? - 10/28/08 03:48 PM
I find it deeply satisfying whenever JohnK can combine theology and audio.
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/28/08 04:46 PM
::bows to audio gods::
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/28/08 11:13 PM
Well I finally caved in and plugged the Axioms into the 663 and the same thing happened only this time the Yamaha shut itself off at the peak.

I knew some of the Yamahas were not a good fit with the Axiom but the plan was to use the 663 as a pre/pro only, it's interesting that the Yamaha website states that their amps are stable down to, but not below, 4 ohms. I guess it doesn't mean much with such a low end model, an Amazon user states that the the 3800 drove the m80s no problem.

So my far pre/amp gambles have not paid off, it looks like I'll have to up the ante just to experiment more.

Still have to hope there is not something wrong with my power situation that is interfering with high current audio, since this is now 2 amps that have crapped out when push comes to shove, although I suppose the second example doesn't mean much . . .
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/28/08 11:53 PM
Two different amps, both shutting down at high volume. Interesting. Could it be at all possible that you somehow have a defective M80 that's causing the problem?
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 12:08 AM

Do you have a friend or family member with a Denon, H/K, Rotel etc. Something that is known to drive the M80s well.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 01:07 AM
No we are transplants from the Northeast, all I have is a lowly 50 wpc Rotel circa 1989, which sounds good but can't be cranked up to a reference volume.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 01:36 AM

Does the Rotel shut down when pushed real hard?
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/29/08 01:38 AM
There was a suggestion about possibly measuring the impedance of the M80s. Impedance varies with frequency and is fairly complex to measure, so it's better to rely on the measurements made by a competent lab, if available. In this case the NRC is certainly highly competent and has done the measurements, which have been shown here. If a particular M80 was somehow not representative of the published impedance curve and was in fact far lower, it should be noted that in that case the DC resistance of that driver's voice coil would measure far less than the typical 3/4ths of the nominal value(e.g., the DC resistance of a driver nominally rated at 4 ohms might typically measure 3 ohms or a bit more). The actual impedance to AC audio signals would be the DC resistance plus some additional impedance caused by reactance at various frequencies. So, if the DC resistance measured across the terminals is say at least 3 ohms, then the impedance at various frequencies will always be higher than that, and if the concern is the minimum impedance, the question has been answered.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 01:48 AM
I guess I haven't wanted to press my luck and possibly damage the speakers? I would have to turn it all the way up and go into distortion, and I would be surprised if it would shut down, I've had it up around 3/4 and it doesn't seem stressed.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/29/08 01:49 AM
Maybe it's time to cart the M80s with you down to Austin? If so, my Denon 3808 stands at the ready to test them. \:\)

Jason
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/29/08 01:50 AM
And if you're really nice, I'll even turn on my subwoofers while you're here. ;\) (inside joke for those who remember the initial audition mishap)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:06 AM
Thanks Jason, I might actually take you up on that, however, I have to say I maintain a great deal of skepticism about it being the M80s, I mean Axiom wasn't born yesterday even if these particular speakers were, and would probably test those last.

I'm more concerned that there could be something wrong with my setup or electrical system that is causing the amps to fail at high volumes, and if I try something like Outlaw I would find myself in the same lower mansion of hell.

A straightforward approach would be to go ahead and order a 3808 so I could know where I stand but that would be a costly option if I continue to pursue an HT build involving separate power amplification, I'm still stuck on that idea so I hate to rule it out just yet.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 02:06 AM
If the Rotel doesn't shut down at 3/4 volume then that tells me the Emotivia is a defective unit. The Yammie just isn't up to the task and not a receiver in which Axiom recommends for the M80s.

It's not your wiring, do you use a microwave? Does it shut down? If not then don't worry about the wiring, that takes far more amps and is harder to run than the amp.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:17 AM
OK thanks once again everyone, I know this has gotten tedious, bear in mind I don't even have a working pair of front speakers!

It's taken my mind off the wait for the rest of the system though, that seems the least of my problems at the moment.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:22 AM
 Originally Posted By: JohnK
if the concern is the minimum impedance, the question has been answered.


That was my read of the NRC data as well, however thanks for the technical anaylsis.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/29/08 02:25 AM
No, as Rick commented, the problem isn't the electrical system; it appears that on occasion there's too much power, rather than not enough. One thought as to possibly a problem with just one of the M80s: connect just one at a time and run in mono on that program material to see if it shuts down when driving one M80 but not the other.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 02:26 AM
 Quote:
bear in mind I don't even have a working pair of front speakers!


Sure you do, you just need an amp that works other than that nice Rotel you have there.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:27 AM
Now if only the folks at emotiva could come up with some ideas!

It does seem to be mainly when their high wattage amps are driving 4 ohm speakers that the protection fault crops up.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:32 AM
Well I have tried with just the left channel because the right input seems a bit loose, but the fault has been split more or less randomly between one or the other channel going into protect, which leads me to suspect even more that it can't be the M80s because they can't both be bad, which would have to be the case if the protection fault would shift from side to side, would it not?
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/29/08 02:35 AM
Yep.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 02:42 AM
The Rotel does sound sweet, it will be going into the study to power the Polks and a Dual turntable, NAD cassette player, and HK CD to CD recorder; great stuff!
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/29/08 03:19 AM
This poor guy is having some 8ohm speakers shut down the XPA 5 at low levels. Emotiva told him it was impedence peaks, come on.

http://www.digitalhome.ca/forum/showthread.php?t=93465
Posted By: St_PatGuy Re: XPA 2 Now! A Keeper? - 10/29/08 03:44 AM
Time to check out some Odyssey amps!

(shameless plug)
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/29/08 03:52 AM
;\)
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 10:47 AM

Or more Rotel, ya know they work.
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/29/08 01:39 PM
Or Outlaw. Outlaw makes some very fine equipment too at prices somewhat less than the equivalent Rotel & Odyssey gear. I was very seriously considering a pair of M2200's to drive my M80's. It just depends on how much money you want to spend.

I do still think that you ought to try to get Emotiva to send you another XPA before you call it quits with them.

And thanks to JohnK for explaining the impedance thing. I didn't know if it was something as simple as sticking an ohmmeter in between a speaker lead or if it was far more complicated. It would seem that 'B' is the correct answer. ;\)



Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/29/08 01:54 PM
I have another idea. It might be a bad one but it is something that I'd try, anyway...

You've said that you've tried running with just one speaker and you're still getting the shutdown. I wonder what would happen if you tried bi-amping just that one speaker? I wonder if you'd get a different shutdown point, or if it would in any way work better, or at least give you an idea of which set of cones is causing a problem for the XPA (tweets+mid vs woofers).

Put an RCA splitter on one channel output from the prepro, and run the splits into the inputs of the XPA, left and right. Then remove the bridge plate on the M80 and run a separate wire from each terminal on the M80 to each output on the amp. Then try it again. I'd be curious to see if it shuts down at (about) the same loudness.


Posted By: Ya_basta Re: XPA 2 Now! A Keeper? - 10/29/08 02:58 PM
When I had my first problem with my RPA-1 (shutting down) Emotiva told me that it was because my M80s were getting hot, then the second time when I blew a fuse, they told me (as I've mentioned before) that the M80s can drop to 2 ohms. I've never gone past 0 on my Denon, I believe the max I pushed the amp to is -10 on my Denon, and the meters are peeking around 1/4 on my RPA-1, so I've never pushed it even close to its maximum.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/29/08 03:13 PM
M80s getting hot, that made me laugh. It is obvious they are in the blame game.
Posted By: MarkSJohnson Re: XPA 2 Now! A Keeper? - 10/29/08 03:38 PM
I've been staying out of this, because I don't want to fan flames without truly knowing what the situation is. But I will say this:

I would tend to not buy an Emotiva product because of incidents such as these. They are arguing (evidently) that the 80s are the problem, but that argument can be turned around another way: As long as I've been on this forum, I haven't heard of any other amps (that are rated for 4 Ohm use) that shut down under anything less than the most severe abuse.

They make a nice-looking, feature-attractive product for a low price point... but I wonder if the guts are really as beefy as people hope. I'd be more inclined to give other manufacturers' budget products the nod first... and I only have M60s.
Posted By: fredk Re: XPA 2 Now! A Keeper? - 10/29/08 04:16 PM
Fannity, fan, fan...
Posted By: pmbuko Re: XPA 2 Now! A Keeper? - 10/29/08 04:40 PM
Sparkity, fuelity, conflagrationity...
Posted By: tomtuttle Re: XPA 2 Now! A Keeper? - 10/29/08 05:39 PM
I don't think it's much fun to bash products, except Bose and Monster, who richly deserve it.

I don't disagree with Mark (this time), but I am also willing to entertain the notion that the impedance curve of SatKatr's M80's is not the same as the one from the NRC. I do kind of wonder about how incremental changes in the M80 over the years might have influenced that measurement. Is that curve dated?
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/29/08 05:46 PM
 Originally Posted By: tomtuttle
Is that curve dated?

I would bet it is a number of years old at least from the v1 days.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 06:35 PM
The website/link Alan gave says December 2005 and it is v2.
Posted By: tomtuttle Re: XPA 2 Now! A Keeper? - 10/29/08 06:38 PM
I stand corrected. Thanks and nevermind.

\:\)
Posted By: pmbuko Re: XPA 2 Now! A Keeper? - 10/29/08 07:04 PM
 Quote:
I stand corrected.


It's when you're sitting down that you're a stubborn mule, eh?
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 07:11 PM
Sorry guys, I feel like I'm letting all of you down who may like be toying with the idea or actively trying to pursue budget separates, I know so little at this stage that it could be me, obviously emotiva might be finicky but some people at emotiva lounge state that when they have played with the cabling like going unbalanced rather than balanced they got the XPA5 to stop acting up. A lot of fuss and bother, but there is a cost I suppose to doing things on the cheap. I would not have gone down this path if I'd known what I was in for but now I'm here I will persist just a bit more, unfortunately I'm a to the bitter end kind of guy, the amp sounds great when it's working and perhaps there's some element in the setup that could be pushing this sensitive amp (at least the amp in my living room if not the model itself) over the edge.

Updates on my latest mistakes to correct any previous misinformation:

1) The Yamaha did not shut down, a fuse in the surge protector blew, I made the mistake of not switching the power cord over to the high current audio section. After replacing the fuse and plugging the Yamaha into an appropriate outlet, it does not shut down even at max volume, but the distortion is pretty scary, and when I turn it down to 0db or a little above it sounds alright but not as dynamic as what I was looking for in my size room (95wpc into 8 ohms all channels driven, currently running two M80s only).

2) Last night I read through both the Yamaha and Emotiva manuals more or less cover to cover and found on pg 28 that I had not run the Yamaha "Advanced Setup" covered in full detail on pg 106 to set the speaker impedance. The speaker impedance is not switchable via the GUI operated by remote control which only gives you "Basic Setup" and "Speaker Setup", you have to sit on the floor, power down, hold the tone control while powering back on and then you use the tone control to switch from min 8 ohms to min 6 ohms, the 6 ohm setting also supports 4 ohms through the fronts. This is important to facilitate volume impedance matching, e.g., the pre out and front speaker out signals carry the same signal level. I powered on the emotiva and as expected there was no improvement, the amp shut down as previously described, with leds maybe half way out but certainly not pegged, although they look as if they want to go to toward full led status before the protection fault kicks in.

You guys warned me about the manuals, I would have thought Yamaha would let you know about the importance of the impedance setting sooner in the manual than page 28, which on the second column states: "Caution If you are to use 6 ohm speakers, set SP IMP to 6 ohms MIN as follows BEFORE using this unit." Shouldn't that be one of the first things stated? I guess they assume low end unit, low end speakers, or something like that.

It looks like I've been spoiled by the quick start manuals that come with most electronics where you follow the basic recipe that includes all the essential elements and then you read the whole manual cover to cover later once you are in the mood to consider tweaking, apparently that's not the case with HT receivers.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/29/08 07:17 PM
As has been mentioned before, the impedance setting only cuts the power output and as you have discovered, the 663 is more than capable of running the M80s in standard mode. This alone should be evidence enough that the Emotiva has an issue. I would try to get them to send another, if nothing else just to see if it is just that one amp.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/29/08 07:24 PM
Oh I didn't see that about the impedance setting but that was my understanding that it just affected the power output of the preamp, good to have that confirmed. Could a crummy preamp overdrive a power amplifier or adversely affect it in some way?

I'll have to call them and see what they say, I have communicated with Lonnie via email but have been dragging this out because I've want to make sure it's not some basic mistake I am making in my setup, given that this will be my first HT system which I am building more or less from the ground up.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/29/08 07:29 PM
The impedance setting only affects the rail voltage to the internal amps, it shouldn't have done anything to the low level output.

I guess the Yamaha could be sending out a slightly higher voltage than normal which could be affecting the emotiva. Maybe you need to run down to Jason's with the emotiva this weekend and try it out with his Denon.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/29/08 07:43 PM
Sounds fun... \:\)
Posted By: RickF Re: XPA 2 Now! A Keeper? - 10/29/08 07:51 PM
Randy and SatKartr are far more patient than I would have been. I would have been running down to the local FedEx office with a used and obviously problematic amp for shipment back to the factory on about day two or three and by now would have had a replacement amp (another brand) powering up my system.
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 10/29/08 08:08 PM
 Originally Posted By: SatKartr

.... (95wpc into 8 ohms all channels driven, currently running two M80s only).

You're the guy that's got 4 M80's, right? You're not trying to run all 4 M80's off of that one XPA-2 - a pair of M80's off each channel - are you?

I tend to agree with Rick. I'd get a replacement XPA from Emotiva ASAP to rule out a defective amp. If that new amp does the same thing, get your money back and buy a different amp from somewhere else that has a full money-back guarantee. If *that* amp has problems too, then it's got to be something in your home wiring or in the M80 itself. You've got to rule out variables here.

Whatever the outcome, keep us informed. I'm curious how this will play out.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/29/08 09:23 PM
Different guy Rick. SatKartr only has 2 (though I'm sure he'd like 4). ;\)
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 09:44 PM
Different guy Jason, that's Peter.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 10/29/08 09:57 PM
Umm, no, wrong Jason, that was JakeWash. I swear, it wasn't me... \:D
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/29/08 10:01 PM

Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 01:28 AM
\:\) Now there's an idea! I am as I just found out going to be in Austin next week and that does pique my curiosity, unfortunately I will be flying and I could barely carry the xpa2 to the car much less transport it on a plane. I kid you not, I thought the reviewer was joking but that sucker is heavy. If I were to write a review there would be only one definite critique from me: it ought to have handles so you can lift it without the risk of dropping it straight through your hd display as you lose your balance on liftoff!

Plus my gps is busted and has to go back for replacement, there's no way I'd find your place Jason and make it back to the office within lunch hour, Austin is tricky, maybe next trip. \:D
Posted By: Spoiler Re: XPA 2 Now! A Keeper? - 10/30/08 01:48 AM

I believe the XPA-2 is 75 lbs...heavier than an EP500?? \:o oy!




Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 01:52 AM
You know if I hadn't smashed the right input while trying to wrestle the amp into position I would probably have already let it go, but it will irk me to always wonder, which was the problem: 1) was my intuition wrong in placing the order, or 2) did I bust it myself before plugging it in?

I'm hoping they take it back, their warranty disallows damage due to shipping and handling, I'm disinclined to represent that.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 02:04 AM
Sat, just to emphasize the point, disregard the direction in the manual as to a lower impedance setting. As was said, this simply reduces the maximum voltage that the power supply section of the amplifier can output, thereby also reducing(following Ohm's Law) the maximum current and power that can be output. This is a safety-type requirement to keep the UL(Underwriters Laboratory)happy by reducing the chance of overheating, but it cuts the maximum power capacity roughly in half, and shouldn't be used. It's unclear what setting you used when you tested the 663, but in any case, keep it at, or return it to, the 8 ohm setting.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 03:17 AM
OK thanks, it sounds pretty thin to me at the moment, I will try it again at 8 ohms, but I must say the 663 gets pretty hot even when run just as a preamp, whereas the xpa2 stays completely cool. I originally tested the 663 at 8 ohm setting but as I said it was a minimal fuse that blew not the amp that cut out, 2nd test was at 6 ohms but if it's distorting when volume is set a few dbls above zero wouldn't that be the same regardless of impedance setting? Guess I'm still confused.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 04:04 AM
Not necessarily. If the amount of power required on peaks at that volume control setting was still within the reduced capacity at the lower impedance setting, then there would be no audible distortion(at least not any due to the amplifier); if the required power exceeded the reduced capacity, audible distortion would develop. This wouldn't occur, or at least wouldn't occur until a still higher amount of power was required, with the 8 0hm setting for the impedance switch or menu.

For example, S&V often tests for the reduction in capacity at the lower setting, and their lab test of the 661(they haven't tested the similar 663)showed that the power was limited to a little over 60 watts at the lower setting. A peak that required say 120 watts would distort at the lower inpedance setting but would be handled well at the 8 ohm setting. The numbers and analysis there may be of interest.

As to heat, don't worry much unless you see smoke and flames(seriously, the protective circuits would shut down before that). High heat may reduce the long-term service life of the unit, but shouldn't be a cause for major concern if operation continues.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/30/08 04:13 AM
 Originally Posted By: myrison
Umm, no, wrong Jason, that was JakeWash. I swear, it wasn't me... \:D
Hey leave me out of this, I didn't do anything.**standing ground, not running away like some others**;\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 04:34 AM
My daughter weighs 75 lbs and I can pick her up no prob but picking up the xpa2 was a challenge. Is that a mass thing? I thought small and compact (xpa2) would be easier, like I say, handles would help. Fedex lists the weight as 92 lbs including box, which weighs what 5-10 lbs?
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 04:38 AM
No. Evil spirits inhabit the XPA2 and they don't like to be picked up.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/30/08 04:40 AM
I am guessing it was just the awkardness of getting the amp out the box, as you said handles would make things alot easier. If you were to open the box around the amp so you could easily get to the corners for hand holds the accident would have not happened.
Posted By: pmbuko Re: XPA 2 Now! A Keeper? - 10/30/08 04:40 AM
JohnK lies. Kids are full of gas. That is why they're easier to lift.
Posted By: St_PatGuy Re: XPA 2 Now! A Keeper? - 10/30/08 04:44 AM
 Quote:
Kids are full of gas.


Chips off ye olde block.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 05:39 AM
OK tonight everything sounds much better again at the 8 ohm setting, thanks for that tutorial, will have to experiment with the HT passage in question again at the 8 ohm setting through the right outlet, from every indication sound will be greatly improved, i.e., certainly not noxious/distorted as it was before at the 6 ohm setting with the 663 even if not as high impact in terms of SPLs as the XPA2 was trying to be, which became moot because nullified by protect.

Very interesting how what you state may relate to dynamic peaks and the need for/benefit of headroom, and how the logarithmic nature of sound perception may give rise to the idea, "You can never have too much power," or does that idea arise mostly because most of us cannot compute how much power we would actually need to propel a given space to a given clean spl?

It seems that the dynamic peaks of HT in general require more headroom than music due to the dynamic range involved, I suppose that is more or less obvious but I still do not entirely grasp the implication in terms of how much head room I actually need/want in my setting due in part to the logarithmic distortion in perception whereby you need 10 times as much power to perceive sound that seems twice as loud (is this not approximately correct?).

BTW what's up with the power ratings with the Yamahas, the 661 is rated at 90 watts into 7 but S&V finds only 53 watts into 6? The 663 is rated at 95 watts into 7, that suggests the amp is not as powerful as I was led to believe, even in terms of backup or surround duty.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/30/08 06:04 AM
 Originally Posted By: SatKartr

Very interesting how what you state may relate to dynamic peaks and the need for/benefit of headroom, and how the logarithmic nature of sound perception may give rise to the idea, "You can never have too much power," or does that idea arise mostly because most of us cannot compute how much power we would actually need to propel a given space to a given clean spl?
If you go to some of the amp power calculators you can get a rough estimate as to how much power you need.

 Quote:
It seems that the dynamic peaks of HT in general require more headroom than music due to the dynamic range involved
Try some classical music if you want to experiment with dynamic range. Most popular music has very limited dynamic range around 5-10 and I would peg a good action movie between 10-20 while classical can go to 50db in some instances.

 Quote:
BTW what's up with the power ratings with the Yamahas, the 661 is rated at 90 watts into 7 but S&V finds only 53 watts into 6? The 663 is rated at 95 watts into 7, that suggests the amp is not as powerful as I was led to believe, even in terms of backup or surround duty.
Welcome to the world of misleading numbers. I know somewhere around here Alan has posted the usual amp testing procedures and it is within these procedures that the specs are taken. I believe the procedure is 1 channel driven fully and the others driven at 1/8? to achieve the ratings. S&V run all channels driven to determine the actual output which usually never takes place in regular use.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 06:08 AM
Sure, it's commonly said that to be perceived as "twice as loud"(whatever that means)requires an increase of 10dB in sound level, which requires 10 times the power.

The power measurements are fine and exceed the rating numbers. As with most receivers, the Yamaha rating is in accord with the FTC power regulations which require two channels to be driven simultaneously at the full rated power for at least five minutes continuously. All channels driven is neither a legal nor a real-world home usage requirement for the power rating, since all the channels aren't called upon to output full power simultaneously on real program material. Note the comments of the tester on this point at the end of the second page in the linked 661 test results.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/30/08 06:12 AM
 Originally Posted By: JohnK
All channels driven is neither a legal nor a real-world home usage requirement for the power rating, since all the channels aren't called upon to output full power simultaneously on real program material.
It might not be a requirement but if you are running a system in 5/6/7 channel stereo would you not be asking the receiver to run all the amps at nearly the same output?
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 06:21 AM
Of course, to the extent that both stereo channels would be equal in level.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 06:34 AM
I never realized just how compressed popular music was until I plugged in the M80s, that's a good suggestion to check out some classical music at least for reference (my wife loves the pop stuff, what can you do? Maybe the M80s will expand her range of musical taste ;\) ), although I suspect the few classical recordings I have will have to be upgraded to provide decent sound quality.

Jason/Myrison provided a link to one of those amp power calculators but I was a little fuzzy on how to perform the calculations, I'll have to go back to that link and dig into it.

I think what you say about misleading numbers is also an issue with the power amp calculator equations, since the numbers are somewhat biased it takes a bit of experience to know how the numbers are actually going to translate into a real world situation, especially with regard to ordering equipment over the internet. Thank God for Axiom! \:D
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 06:36 AM
Thanks for pointing out page 2, I did miss that one.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 10/30/08 06:46 AM
Yeah Sat, there's a whole world of great music waiting for you out there. I stand ready to make classical suggestions in almost unlimited numbers(I have about a thousand classical CDs). There's quite a few in the "Stunning Recordings" thread in "Stereo".
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 06:49 AM
 Originally Posted By: JohnK
All channels driven is neither a legal nor a real-world home usage requirement for the power rating, since all the channels aren't called upon to output full power simultaneously on real program material.


This is what I have been wondering about the most in terms of headroom, because the promo (AL video on You Tube?) I saw for the A1400-8 seemed the same as the latest Emotiva rap; both eschewed the monoblock model (e.g,. MPS-2 in Emotiva's case) in favor of a high power amp with a massive power supply that could provide maximum power to the one or two channels that need it most to facilitate HT or front speaker content and support dynamic peaks. I am now leaning toward Outlaw (rather than XPA1s, anticipating I will give up on the XPA2) due to budget yet am trying to decide just how many watts and whether the statements regarding a unitary high wattage A/B amp with minimal cross talk versus a couple of powerful monoblocks will be more satisfactory, given that HT is the priority and I have a pretty big room to fill.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 06:51 AM
Yes I saw that thread, that's why I didn't bother to ask, I already see some suggestions I can get started with. \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 07:38 AM
 Originally Posted By: jakewash
I am guessing it was just the awkardness of getting the amp out the box, as you said handles would make things alot easier. If you were to open the box around the amp so you could easily get to the corners for hand holds the accident would have not happened.


True, but the problem was when buying an amp on the cheap, I had to keep the box intact and didn't want to slit the corners to get a good grip on the edges so I could send the amp back if necessary, and it looks like it may be necessary! If I had a rug like Gene Dela Salla instead of wood floors I suspect everything may have been different, may be it all could have worked out just like in the review.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 10/30/08 07:45 AM
 Originally Posted By: St_PatGuy
 Quote:
Kids are full of gas.


Chips off ye olde block.


You guys are such clowns, I need more silliness, sign me up for that. My life is too hard! \:D
Posted By: RobbP Re: XPA 2 Now! A Keeper? - 10/31/08 06:33 PM
When I first started looking at upgrading my system six months ago Emotiva was at the top of my list for amps. As time goes on I'm starting to see more and more stories like this cropping up. The customer service may be fantastic but I live in Canada, what's it going to cost me to have it shipped and repaired once it's off warrenty? They are slowly falling down the list and might drop right off. I'm trying to decide if I should pick up some used Rotels that are for sale locally for a pretty good deal.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 10/31/08 07:00 PM
Personally I would stick with the tried and true Rotels.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 10/31/08 08:54 PM
Or Odyssey, they come from the long German Symphonic line.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 10/31/08 09:13 PM
 Originally Posted By: sirquack
Or Odyssey, they come from the long German Symphonic line.


Who cares \:\)
Posted By: St_PatGuy Re: XPA 2 Now! A Keeper? - 10/31/08 10:06 PM
*sniff sniff* I smell some Rotel snobs.






Nope, sorry, that's just JP.

Posted By: doormat Re: XPA 2 Now! A Keeper? - 11/01/08 04:48 AM
 Originally Posted By: RobbP
The customer service may be fantastic but I live in Canada, what's it going to cost me to have it shipped and repaired once it's off warrenty?


Actually, even on warranty:
"International Customers please note:

Shipping costs for repair and warranty work on products outside the continental USA (including Alaska, Hawaii and Canada) are the sole expense of the owner. Owner is responsible for all shipping costs to and from Emotiva, as well as any brokerage, VAT, taxes, duties, and any other costs associated with the importation and exportation of said product."
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 11/01/08 08:43 AM
I would have hoped Emotiva would have been willing to foot the bill for shipping of a warranty item.\:\(
Posted By: Hutzal Re: XPA 2 Now! A Keeper? - 11/01/08 11:06 PM
Like Peter Chenoweth, my M80s have had no problems with the LPA-1. The reason I decided on the older LPA-1 and not any of their new stuff is simply because others have used this amp with great success. I am not sure what kind of poor quality control is in their newer/higher line of amps, but the good old LPA-1 is tried and true, perhaps you should give it a try, you can find em used for around $400 plus shipping. The warranty is transferable so if you find a newer one, you can still have around 4.5 years of warranty.

Just a thought. I wouldn't even think about purchasing their new amps, the LPA-1 hasn't failed me yet. If you are only driving 2 channels, the LPA-1 puts out around 270 watts per channel. (but you only need 1 watt, what a waste eh?)
Posted By: Family Man Re: XPA 2 Now! A Keeper? - 11/03/08 10:54 PM
If you could spare a little bit more, i have just connected the A1400-8. i blasted my garbage reciever and it still sounded amazing.

If you can spare a little bit more, this is the amp for axiom's home theater speakers.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 01:27 AM
"A little bit more"? Try almost 3grand more, you must be loaded. \:\)
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 01:35 AM
Hold on, now how much did those Odyssey monoblocks that you recommended cost?
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 01:54 AM
About $1500 total.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 03:00 AM
Hey that's not bad, I must have googled the wrong item. \:\)
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 03:06 AM
Basically Klaus built me the Stratos monoblocks in Khartago cases.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 11/04/08 03:13 AM

Save yourself $500 and get the Rotel RB1080. It's a proven winner with the M80s.
Posted By: myrison Re: XPA 2 Now! A Keeper? - 11/04/08 03:14 AM
Randy, did you like one case better than the other, or why did you ask for that custom combination?
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 03:15 AM
A few pics of my custom built amps by Klaus. Did I mention they have a 20year warranty!






Posted By: pmbuko Re: XPA 2 Now! A Keeper? - 11/04/08 04:26 AM
I like big caps and I cannot lie.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 11/04/08 04:43 AM
Nice caps!
Posted By: CV Re: XPA 2 Now! A Keeper? - 11/04/08 04:44 AM
The cap size is making me capsize.
Posted By: pmbuko Re: XPA 2 Now! A Keeper? - 11/04/08 02:21 PM
One size fits all?
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 09:27 PM
I finally got Lonnie on the phone and he concurred that the XPA2 and M80s appear to be a mismatch. He states that with the original M80s the crossover did appear to drop below 1.5 ohm at certain frequencies (he didn't specify what testing was done). Lonnie also stated that the the XPA2 does not have a current limiting circuit as does the Rotel, this is an intentional design to allow the xpa2 to express the full dynamic range in an unfettered manner.

The only emotiva amp(s) he would suggest as a consideration to run the M80s would be two XPA1 monoblocks, which are able to go down to a 1.5 ohm load. These will be $999 apiece so the cost would go up quite a bit with that solution.

The sound of the XPA2 with the M80s at high volumes was quite good, however perhaps this is the definitive word regarding their incompatibility at just such high volumes.
Posted By: jakewash Re: XPA 2 Now! A Keeper? - 11/04/08 09:33 PM
The original M80s croosver was reworked back in 2002-2003 and the newer tests that have been done prove it does not get anywhere near 1.5ohm.

For that kind of money you might as well get the A1400-2 that is now looking like it will be in production soon.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 09:34 PM
I'm not trying to doubt Lonnie as I had a lot of conversation with him 3 years ago about the MPS1. But, he had never even heard of Axiom at the time. Even the prior m80's never dipped below 4ohm at any frequency, the Soundstage graphs don't lie. Sounds like an excuse to me. Oh well.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 09:41 PM
 Originally Posted By: jakewash
For that kind of money you might as well get the A1400-2 that is now looking like it will be in production soon.


Absolutely, I am just passing along the info for those who had expressed interest in the XPA/M80 pairing question.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 09:46 PM
I think the main difference is that now he is acknowledging the incompatibility between the design of his amp(s) and the M80s and not attributing it to setup issues or a defective unit. Also he is happy with his design so we should not expect a change in his future amp designs to improve this situation with regard to the M80s.
Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/04/08 09:58 PM
Does he understand it is not just m80's. I know people with Rockets having the same problem on other forums.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/04/08 10:05 PM
I didn't want to press him on that point, I think we are all wise to suspect the veracity of the info about going M80s going below 4 ohms; my goal here was merely to convey/share that the problem has been acknowledged and there are no current plans to improve compatibility on Lonnie's end.
Posted By: tomtuttle Re: XPA 2 Now! A Keeper? - 11/04/08 10:20 PM
That is disappointing news.

I don't want to pile on, but lack of "compatibility" seems like a pretty benign way to phrase what's happening here. I'm really surprised that the Emotiva design seems to be having such trouble with low impedance loads. Heaven help anyone trying to drive Maggies, eh?
Posted By: Wid Re: XPA 2 Now! A Keeper? - 11/05/08 02:44 AM

When I was researching the Rotel amps never once did I read that they were current limiting.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/05/08 03:01 AM
Makes you wonder where all the "info" is coming from, BTW I forgot to add that Lonnie states that it is the "high power amps that are not current limited" in the Emotiva line that do not pair well with the M80s, presumably this does not include some of the lower wattage amps in the Emotiva lineup.
Posted By: Wid Re: XPA 2 Now! A Keeper? - 11/05/08 11:56 AM

Did he used to be a car salesman? What a line of shit.
Posted By: SatKartr Re: XPA 2 Now! A Keeper? - 11/05/08 05:22 PM
Ah yes, the perfect vehicle, for SK's Bogus Journey!
Posted By: Ya_basta Re: XPA 2 Now! A Keeper? - 11/06/08 12:51 AM
 Originally Posted By: SatKartr
Lonnie states that it is the "high power amps that are not current limited" in the Emotiva line that do not pair well with the M80s, presumably this does not include some of the lower wattage amps in the Emotiva lineup.


I wish I was notified of this when I was having problems with my RPA-1.

Sounds like Emotiva amps are the PC of computer systems, oh yes, loaded with Vista also
Posted By: Wid Re: XPA 2 Now! A Keeper? - 11/06/08 12:56 AM

I'd never buy one, I will say they sure do look good though.
Posted By: merchman Re: XPA 2 Now! A Keeper? - 11/06/08 12:59 AM
You're right Wid, they do look nice but looks ain't everything.
Posted By: JohnK Re: XPA 2 Now! A Keeper? - 11/06/08 02:22 AM
Any competently designed amplifier has to be "current limited". In the most extreme case, where a short has occurred due to a loose wire or whatever and the extremely low resulting impedance creates a sudden huge current surge, the amplifier has to shut down almost instantly to avoid damage. Protection against less severe requirements is also provided in varying degrees.
Posted By: Murph Re: XPA 2 Now! A Keeper? - 11/07/08 12:49 PM
 Originally Posted By: wheelz999
Sounds like Emotiva amps are the PC of computer systems, oh yes, loaded with Vista also


Nice One!
Posted By: PeterChenoweth Re: XPA 2 Now! A Keeper? - 11/07/08 02:38 PM
What a load of crap from Emotiva. \:\(

"They don't pair well with M80's."

Whiskey Tango Foxtrot. Sounds to me like they're just lying about the specs of their amps. Pure and simple. If the specs state it's 4-ohm capable, it better reliably power 4-ohm speakers, period.

It still blows my mind that my lowly $499 LPA-1 has no trouble at all with my M80's, when all of their 'high-end' amps can't do the job.

I'm just one insignificant customer, but I'm now seriously rethinking my preorder of the UMC.

Posted By: SirQuack Re: XPA 2 Now! A Keeper? - 11/07/08 06:38 PM
I know when I was having problems with my MPS-1, Lonnie mentioned it was the only amp with the waveform limiter circuit. Not sure about the newest models...
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