Axiom Home Page Forums General Discussion Technical Questions Denon with external amp

Just wondering. When you hook up an external amp to a Denon receiver does this disable the amps on the Denon?

I've not tried hooking up an external to my Denon, but isn't that what the pre-outs do? once you hook a speaker up to the pre-out, you have bypassed the amp for that particular channel while leaving the amp working on the other channels?

I thought so but I really don't know.

Unless its got some little loops in the back like Ive seen on old Yamaha amps then the receivers amp will still be running, but given that its got no load its not going to contribute much noise or load to the rest of the system. Don't worry about it.

So then in theory one could bi amp a set of M80's then. If you took your AVR and pre outed the two mains and then used the second amp as well....no?

Would bi amping be better than one dedicated 300-350W @ 4 ohms stable be?

Later
Phil

You can't bi-amp the same signal. As soon as you use the preout for a particular speaker on the receiver you can't hook up the same speaker to the receiver output for that speaker. I guess I should let Let John K answer this.

you could bi-amp if you had bi-wiring and bi-speakers.... but theres not much point... not that theres ever been much point to bi-wiring.

A bi speaker is one that can switch one of its outputs to an input, right?

hahah

I thought that was a herma speaker.

Yeah Rick, I'm pretty sure that is the case with most receivers. As soon as you use the "pre-outs" for any given channel, that bypasses the internal amp stage. However, I guess I've never tried to hook up a pair of speakers to the regular speaker jacks, AND use the pre-outs at the same time.

I can't remember what receiver, but some model had a warning against hooking up speakers when the pre-outs were connected to amps.

I do remember that someone used a Kill-A-Watt on a previous Pioneer Elite flagship receiver. He found that when there were no speakers connected to the internal amps they still drew some power vs. going into the settings and disabling the amps. It wasn't much, like 5 Watts, but that does add up over time. My current Pioneer, while having pre-outs has no setting to disable the internal amps.

Ricky- I'm using the pre outs for five channels that go to a 5X200 external amp, and using the 3808's amp for the surround back channels.

Mike, are the binding posts that you're using the preouts on still active?

Even if a receiver leaves both its internal amps and pre-outs active at the same time, bi-amping is going to be a problem. Adjusting the channel trims will cut both the internal amp, and the signal going to the external. Unless the external has exactly the same gain as the built-in, you're going to end up with half the speaker at a different level. You'd have to use an external amp with it's own trim setting.

I have no plans on anything like this, the question was brought up and I was looking for the correct answer.

Rick, most(all?)HT receivers don't have a device to cut off the pre-amplifier voltage from the internal amplifier output channels when the pre-outs are used. This can be tested on any particular unit by inserting an RCA plug(doesn't have to be connected to anything)into the pre-out and observing whether the regular sound from the receiver to that speaker is cut off.

An example of where a cut off does occur is using the headphone outputs of most HT receivers. Since these units(contrary to some belief)don't use a "cheap" separate headphone amp, but instead the regular amplifier greatly attenuated for headphone use, the output would no longer be suitable for driving speakers. Therefore, inserting the headphone plug moves a mechanical switch which cuts off the pre-amp voltage from the regular output channels, which merely continue at "idle".

Phil, more than connecting a separate amplifier to one section of the speaker is needed for true bi-amping and to have any significant benefits. An external crossover(usually electronic)has to be used ahead of both amplifiers so that each receives only the desired limited range of frequencies to amplify. The internal crossover in the speaker has to be removed, or at least bypassed.

Thanks John.

I'm using the pre outs for SEVEN channels FROM my Denon 3808 to my external EMOTIVA AMP (2). SQ is so dynamic and lots headroom. I will never go back to AVR. The best sound I was missing from my Axiom speakers for a year until I was introduce to me from this forum. The reason I did upgrade was that Denon can not bring out the best of these AXIOM speakers. With external amp,I can hear the musical instrument details and the punch of those Axiom mid-bass sound so good which I was looking for in these AXIOM speakers. But, I would like to share some issue I ran into with EMO amp and my M80V2. Right now I am stucked with the so call distortion and clipping issue with EMOTIVA amp (XPA 2). Believe me with the external amp it's sound very good, but but be careful with external amp make sure it is a 2 ohm stable amp if you are pairing with M80v2. This Issue-DISTORTION AND CLIPPING WHEN EVER I PUSH the volume up. It is not that loud, just when I play above my listen level for demo to friends with heavy rap/pop music. Some how some where the M80v2 impedence dipped below 2ohm. Other than that it sound very good with external amp. I am kinda disappointed with my M80v2. I thought m80s are suppose to be an efficient 4 ohm speaker/easy speaker to drive . O well. I am returning my Emotiva XPA 2 next week from the 30 days in home trial period. Plus,I tried Outlaw amps and Adcom, EMOTIVA amp sound better and cheaper. If you have other Axiom speakers besides the M80 your be fine with any external amp.

At no point in the impedance curve does the M80 dip below 4 ohm.

With the graph it looks real good on paper. This is the curve that sold me with Axiom speakers. But, believe me, when you have the 80s in the room and play demo loud you will find out the what 80s can lead into distortion. It does dip a lot lower than that. Before the external amp. My denon never clip. Right now I am listening with my friend. He is new in HT audiophile world and listening to my system as I typing. It did clips twice now. We played Snoopdog, alicia key, Jay Z...anything with heavy bass it will distort. Plus, I have my neighbor brought his Polk LSi 15 (4ohms) and we are doing A/B right now...into 5 mins. Polk is doing OK. I am stuck with the 80s. They do sound very dynamic with EMOTIVA AMP...I am looking into other amp right too power my 80s.

I know what the M80s can do, I've had them nearly 7 years. I power them with a Rotel RB 1080 and never had the Rotel go into protect mode. A good quality amp should have no problem driving the Axioms to ear bleeding levels. The Rotel can indeed do it.

If I'm not mistaken, haven't there been complaints about Emotiva amps shutting down on other 4 ohm speakers besides Axioms?

Yes. This is my first for going external. Thanks for sharing about the Rotel. I just learning now that I have to find an amp that is stable at 2 ohm to drive the 80s because Rotel is stable at 2 ohm. EMO XPA 2 amp is not. I will look into Rotel and can you tell me where you get yours. I am looking into 2 channels amp that is under $1000.00 and around 300 watts or higher the better. Let me know. Again, I think 80s do dips below 3ohms and fews amp out there can handle those low impedence load. Thanks

The high end Emotivas are the only external amps we've come across with problems with the M80s. Outlaws, Rotels, Parasounds, Crowns, Axioms (of course), Denons, no problem. High end Emotiva? Problem. I wouldn't be pointing at the M80s...

I've driven my 80's to some pretty darn high levels without ever once clipping the 80s and it's only rated at 75wpc.

I'm with the others, it ain't the M80s.

Rotel is only sold by local retailers. Check the Rotel site to see if you have a dealer near you.

Seems strange the Denon doesn't shut down but the EMO amp does. That should tell ya something about the quality.

The graph I posted was done by a third party, SoundStage , and was done independently. Once again, the M80s do not fall below 4 ohm.

Did you test them to come to your conclusion?

No measure just by reading lots of reviews such as http://WWW.skiingninja.com and many Axiom owners discussed in EMOTIVA Forum. I will post the website that talks about the 80s impedence dip below 4 ohm. Believe me I love Axiom speakers. Denon do not have thermal heat sensor. That they will not shut down, but the play loud and no dynamic details compare with what I am hearing from EMOTIVA AMP. I am planning to return the amp next week. Also, I did talked with EMO Tech. and they can not believe M80v2 is very hard to drive...Well, I believe all your words and other reviews are true. Until now, I experienced what is really mean with clipping issue. Thanks again. I will look into Rotel and Adcom.

Yeah, the Ninja has a serious beef with Axiom (particularly because of this forum, I believe)--and he hasn't tested the current M80s.

It's really your choice as to which forum population to believe, but at least we've got the graphs on our side.

And....those graphs are third party, as Rick mentioned.

I take Soundstages word and measurements over the ninjas any day.

I read a review of the Rotel amp I use and it didn't fair well with speakers that dipped below 4 ohm. I've never had a problem and that would indicate to me Soundstages measurements are correct.

You can read it here.

Wid...what I don't understand is why my m80v2 do not pair well with EMO amp, but are perfect with my neighbor Polk LSi15 with no clipping. This is all new to me. First when I bought my Axiom m80, I thought any amp with real power to drive them will have no problem and only the underpower amp is the cause of the clipping.

GS, welcome. "Believe me", or "I think" can't overcome the solid evidence of the measured curve which Rick showed. This was made not by SoundStage itself, but by the NRC(National Research Council of Canada), one of the world's most highly respected independent audio testing organizations. The M80s can be driven to beyond safe listening levels by your 3808 and similar units.

Yes. I am on your side too. I own Axiom speakers, and this week I really experienced the clipping issue with m80. I read here and EMO forum many stated the 80s are difficult to drive speakers. So I was being stubborn, I tried with EMO amp and now experience the distortion/clipping problem with my speaker. Also, earlier this week I spoke with Axiom tech support...they also said 80s do dipps into below 3 ohms in some frequency. Well, I have to find the amp that advertised in the stable 2 ohm not 4 ohm. I learn my lesson here.

It's fairly simple. The Polks are easier to drive. The M80s draw more current from an amp than the typical 8 ohm speaker making it hard for the the amp not to run into over load.

If it was a well engineered amp it should not be having problems. Look at your Denon, it will drive the M80s fine.

What Axiom tech told you that?

JohnK-Thanks. I do believe the reviews last year that got me hook with Axiom speakers and pulled the trigger. Also, I have in my family are Klipsch RF5 and the sound increabible with EMO Amp. Here listen to these
http://www.youtube.com/watch?v=9jRwSgey-mg
http://www.youtube.com/watch?v=KFvl3rsqZn4

Brent...on the phone and phone conversation.

Really. He has given me the wrong info before too.

From another Axiom expert

Wow! After reading Alan's thread I do feel safe. Wid-I discovered the clipping problem happen during music play in Direct and PureDirect mode from Denon DSP. 2 Stereo, 7 ch stereo, and Dolby Digital OK. Could it be the pair problem DENON and EMO amp.

Thank you guys for all your help. I will talk with EMO tomorrow about this clipping with my M80v2. Good night all.

http://emotivalounge.proboards.com/index.cgi?action=display&board=amps&thread=4057&page=2#60582

You're not going to get satisfaction from talking to Emotiva about this issue. They - predictably - assert that the M80 is difficult to drive. However, the Emotiva amps seem to be the only ones that have that difficulty. It's not a "pairing" problem between the Denon and the Emotiva. It's not the M80's causing the distortion. That Emotiva amp has a problem with difficult loads. Follow Wid's advice and get a Rotel or one of the brands Ken mentioned. Do a forum search here for Emotiva and read the many, long, detailed threads that detail the agony of people like you that have tried this before.

A pair of Outlaw monoblocks might fit the bill.

Look, I desperately want to like Emotiva products. Their company is run by fine people. I like their style. I like the value proposition. But there is something about the engineering inside the XPA series amps that just doesn't play nice with the impedance presented by certain speakers.

As others have mentioned, if you're not hearing the distortion at similar volumes by simply using the Denon's onboard amps, that should tell you everything you need to know.

What the guy with beer-breath said.


And I like their pretty blue lights.

Anyone who knows anything knows that blue lights are the coolest!

I agree wholeheartedly with Tom. I'd love to like Emotivas, but I'm unwilling to give up the speaker sound I love just to get an amp.

I agree with football head, blue lights are the best.

While blue lights might look nice, they can be awfully distracting on the rack while trying to watch a movie (if they are in sight). Some equipment with blue lights, if not implemented properly are blinding.

I, too, find blue lights generally way too bright. Pretty, but I don't buy equipment to look at the equipment.

One of the prettiest pieces of equipement I've owned was a Marantz 2252B receiver. It was all brushed aluminum (even the radio dial) and had red and blue lights. Loved that thing. Of course, those blue lights were light bulbs behind blue plastic or something like, so that's a bit different.

Blue lights are cool!

I've read that some of the newer Rotel gear has non-dimmable blue lights, which as the good Dr. states can probably be very distracting if the equipment rack is in sight while watching a movie. That is what I really like about having the equipment rack behind the seating area of the room, I really like this guy's setup but the Rotel lights are mighty bright though.

I concur.

Thats a nice rack!

I concur with your concurrence.

Speaking of a desire to see nice racks, where's Charles been lately?

And, I like my blue lights dim...they better represent me.

dim and dimmer...

There's always wheelz's photo thread ...

HEHEHEHE

That color temperature joke didn't get by me.

...I was going to correct that.

Speaking of lights on components, are any of you guys aware of some sort of tape or something that can be applied over top of said lights to dim them even more? The lights on my APC Power commissioner are set to their lowest setting, but they are still fairly bright.

I didn't know if there was some sort of film available that I could adhere across the front of the unit where the lights are. It would obviously have to be a clean look and inconspicuous.

Any thoughts?
Thanks

I used double-sided tape to put a quarter over the spectacularly bright blue circle of lights on the DTV receiver in our bedroom. It's ghetto fabulous.

Am I helping?

LOL Tom, yes you are helping. Now I know what to do if I want to "pimp my room" .

Cam in my work plane a couple of the digital displays are like that at night time, even with the dimmest setting they are still bright ... I took some static cling window tinting and cut it to fit the face of the display, works great and it can used over and over again.

I don't know if that would work with your application or not but it's a thought, also that tint comes in various colors and shades so it can be matched fairly easily.

That's awesome, Rick! I know exactly what you are talking about, as I was going to get some professionally installed on my windows. I really think that's my best option; I'll pick some up at the local hardware store.

Thanks again, man.

Anytime brother ... I hope it works for you!

Great tip Rick, hey, where is that audio ideas and tips thread.......

HI guys...I'm back and have some update. Well, EMO told me just return XPA 2 for full refund because I am not happy and try their only top notch line of amp monoblock (XPA 1)that can take a difficult load, M80. XPA 1 is a 2 ohm stablize amp. But, man it's like $1k a piece kinda over my budget at this time. I might give them a try. Also, I wanted to add to my external amp experience that I did tried out Outlaw monoblock M2200 with M80. From my OWN opinion and HT set up, Outlaw sounds alright but EMO XPA 2 sound more dynamic and detailed base on my HT set up and my ears. But, man there is something I like about the EMO amp sound that matches very dynamic sound which I really like coming out from my M80. Tell me this... I don't really do not understand much.It just that when I demo and crank up the volume in the 3-6 mins., distortion and clipping problem happen during music play in Direct and PureDirect mode from Denon DSP. 2 Stereo, 7 ch stereo, and Dolby Digital OK. Could it be the pairing problem my DENON and EMO amp. I will post my HT AXIOM speakers PICs set up soon. Thanks again for all the adviced and opinion from the AXIOM forum.

How do you have the M80s crossed over in the Denons set up? Do you have them set to small?

Hi WID...nice to hear from you again. Much appreciated to come on line today. Here, my Denon configuration set up.
All my speakers crossed over to SMALL. F/R at 40 hz and sub is LFE with 80Hz crossover.

I would try crossing the M80's over at 60Hz or 80Hz instead.

OK. I'll try both 60 and 80Hz. But, why I get distortion in the DIRECT AND PURE DIRECT mode. In Pure/Direct mode I hear very different, much better dynamic sound and sound a lot better than 2 channel stereo mode. Pure/Direct mode are my regular 2 channel for my music listening. Is it too much bass in these two modes that is coming from my Audyssey. Or should I re-calibrate my system again?

I would try the same. It would ease the work load of the amp.

Ok thanks. I'll be back later on today for the update.

Would it be necessary to do Audyssey calibration again? Or just leaving as is.

If you ask in regard to just adjusting the crossover then no noeed to run Audyssey again.

Wait a second, you're running Audyssey EQ? Turn it off and see if you like it better.

Also, what volume levels are we talking about here?

Oh no, you didn’t . . .?

Well, we have to reduce the variables--or at least get some more data. Changing the crossover is unlikely to affect distortion, and I have a hard time believing, after thinking on it, that the Emotiva is distorting rather than just shutting down if it can't handle the impedance. There's something else going on here.

Sorry Ken. I thought you’d know I was just poking fun at the Audyssey Posse.

Oh, I figured as much.

I’m probably wrong, but I thought that when in direct or pure direct there was no EQ applied and it was just straight stereo??

I’m also quite curious just what SPL levels you are experiencing when you say it clips. I can’t be in the same room with just the 3808 driving my M80’s. Way too loud. Well over 100 DB.

One other thing to be cautious about, is if you are actually hearing clipping, you’ve already crossed over to a clipping state well before you hear it. I’d stop doing that before you screw up your drivers.

I will test my XPA-2 and M80s in direct mode and see if I have any issues with heavy bass. The XPA-2's meters should help indicate when it is being driven too hard. I am also curious at what point the m80 woofers will start to bottom out. I don't see them producing really low frequency bass at very high levels without a sub to help. They do however produce a lot of punch with bass that is around 45-65 HZ (just guessing on frequency). With Rap music or any other low frequency bass I have to use my sub to get strong output.

Ok I dont have a ton of bass heavy music, but I do have the Grammy nominees cds from 2009 and 2010. I tested with Apologize from one republic, I kissed a girl- Katy perry, from 2009 and poker face - Lady Gaga.

I used my Checkmate cm-140 spl meter C weighted and turned up these songs to 100db. which is about all I can take. The XPA-2s meters were peaking at 8 blue LEDs out of 12 I cant remember how may of the twelve are red? Maybe four. This is with the sub removed.

My findings are IMHO that the bass is not as strong as I would like it. The mids and highs sound more strained then they do with the sub/crossover turned on. The m80s are easier to listen to at these levels with the sub on. I am not hearing any glaring distortion they are just more harsh/a little strained sounding. At these levels the bass is starting to bottom. It sounds like I am reaching the limits of the woofers. I could drive them harder I think but I don't want to damage my equipment or ears.

For me these heavy bass songs sound way better with my sub. The highs and midrange are crisp and clear. And the bass output is much stronger as expected.

Not sure if this helps just my observations.

OK I added the sub back crossed over at 60hz and at the same volume setting I am hitting 108db and the sound is easier to listen to than without the sub at 100db however my ears are telling me that this is all I can take in one sitting. My XPA-2 is cruising along at 4 LEDs lit.

I would return the XPA-2 and get something else. If it’s distorting (staining) at 100dB while showing in the “blue” there is something wrong with it IMO. As a test to be sure it could handle it I played some very intense GOA Trance (150+ BPM) on my Onkyo 3007 at 100dB 3 meters away for two hours w/o noticing any distortion or shutting down with no extra ventilation. If a 140w/ch receiver can handle the M80s w/o a problem so to should a 500w/ch @ 4ohm amp. For that matter a 75w/ch tube amp should be able to handle that with just a tiny bit to spare.

OTOH, if you can’t listen at 100dB then it really shouldn’t matter that the amp can’t handle it.

Seems like Emo is having quality control issues with parts or something. I can’t think of what else would explain some people having no problem at all with a particular amp driving the M80s while others have shutdowns or distortion at levels it should breeze right through. But I’m sure Emo will blame the speaker.

I really doubt the M80s are bottoming out the drivers. You might be hearing the limit of the amp.

Irreversible hearing damage occurs at 140 peak DB (instantaneous) and 104 sustained DB (one hour). Be careful.

I spent most of the time working outside in the yard hoping to stave off the neighbors from calling the cops if they didn’t like it. When inside except for an occasional listening test I was wearing double hearing protection.