Axiom Home Page Forums General Discussion Stereo Stereo amp recommendation?

I like the HK 3480(120wpc) but looking for more oomph for my M22ti, I've look at a few, Subwoofer output is a must.

1)Cambridge Audio Azur 640A, it appears to be a good buy but only has 65wpc so it's a bit wimpy, I'll more than likely disappointed with the ouput I can from this IA.
2)NAD C272 150wpc and the HK 3480 as the pre/pro, not sure if this is a good setup.
3)NAD C372 150wpc IA, a complete replacement and I don't have to keep the HK 3480.
4)Outlaw M-200 200wpc monoblocks, use HK 3480 as pre/pro.

budget is under $700.

well, if you HK is already rated at 120 watts, then the NAD C272 at 150 watts will not be much of an improvement..

i would go with the 200 watt monoblock, if you really want a significient diference in power level and sound output.

just my opinion.

bigjohn

reason why I'd considered NAD C270 or C372 is the dynamic power rating, 220w/340w/460w @8ohm/4ohm/2ohm. I could be wrong but the real world performance it's probably close to the Outlaw monoblocks.

Hi demasoni,

Keep in mind that "dynamic power" ratings are measured in milliseconds (a few thousandths of a second). It does not mean that the amplifier will deliver sustained power output at those levels for more than a fraction of a second.

Generally speaking, the power supply and heat sinking of a basic power amp will be more robust than any integrated amp, so you could expect greater sustained power output in real-world terms than an integrated amp would deliver.

Dynamic power ratings tend to be very misleading. They are often quoted at low impedances as well. The amp may deliver that power for a fraction of a second and then shut down from overheating into a 4-ohm or lower-impedance load.

Regards,

The HK3480 has 120 watts per channel, and low impedance capability to 150 watts.
The M22's have two 5" drivers and a tweater. Thats like a center channel speaker.
It's SPL is 93db. Just how much power is needed to adequately drive such a speaker?
It seems to me that the HK3480 is overkill already.

Dan

thanks for all the great advices, it looks like the monoblocks should give me the most improvement over the HK 3480.
Dan, no doubt the M22ti are very efficient and it doesn't need that much power to drive them, generally 50wpc is enough for moderate listening level, though the M22ti are rated up to 200w, I was under the impression that either match the power rating or overpower them a little should get the most out of these very fine speakers.

Honestly I do not know for sure if I could hear any difference, but I'm expecting about 2~3 dB of headroom and overall music dynamic improvement with 200+ wpc amp. Underpowering the M22ti for extended period of time can't be good, especially when I crank them up couple times a week, no? maybe you were right about the HK 3480. The volume level of this receiver can go from -80 to +18 dB and I have never drive them past the 0 dB mark, moderate level stays somewhere between -40 to -25 dB, at night it stay at around -50 to -40 dB, and -15 to -5 dB is pretty much the reference level I prefer, anything higher will make my ears bleed.

Sorry, I just had to smile when I saw your post.

A month ago : "I'm just gonna buy some little speakers for my office, let's try these Axioms".

Today : "Not sure my rock-solid 120 W/chan receiver has enough power to get the very best out of these speakers, maybe I should add a separate power amp"

Seriously, my first thought would be that spending $$ on a sub would make you far happier than spending $$ on a new amp. With bookshelf speakers and no sub you tend to turn the volume up higher to get bass... and with a sub you find that you don't need to turn the volume up so much.

I'm not even talking about high-pass filtering the signal going to the M22s yet, which reduces your power requirements even more, just having the sub run "in parallel" with the mains makes a big difference in the way you will listen.

Good luck with whatever you decide.

JB

I don't have M22s but have M60s. All I know is that after I switched from my NADs 70 watts/channel to two outlaw monoblocks, I noticed a distinct improvement in dynamics and 'punchiness' (forgive me). It was worth it. Although its a fine amp, I'm not necessarily recommending Outlaws, just recommending more headroom.

I know someday I will move up to a better amp and the best thing about having the separate amps is that in the future, I will move these babies to my stereo upstairs.

Bridgeman(JB).

I know, it's funny isn't it? ever since I got hooked on the Axiom I've found myself keep looking for excuses to upgrade stuff, it's like a black hole that you just can't seems to filled up, this hobby is addicting!!

As for the Sub, you're definitely right, I've already narrow down to the Onix Rocket UFW-10 and SVS PB12(aka PB1). I'm leaning more toward the SVS and I'll make my decision tonight and order either one of the sub tomorrow :-)



Riffman,

I'm going to take my time to look around more, the Rotel RB-1080 appears to be a very nice 200wpc stereo as well, I'm still trying to decide if it's worthwhile to sink another chunk of money on something I might not need.

DE, as Dan pointed out, your 3480 should have plenty of power for your M22s. No, the maximum power rating that a speaker can handle without going up in smoke has nothing to do with how much it needs, and no "match" of the maximum rating is needed. Note that at a comfortably loud level your M22s will use 1 or 2 watts; it's unlikely that even split second peaks will use more than a hundred watts. Unused headroom just goes to waste.

Not to hijack your thread or anything, but I really really like my SVS PB1-ISD. It is a fantastically solid and satisfying product. I've never heard the Rocket and know it is a fine product that gets good reviews. The small size of the box always bothered me on that whole "you can't reason with physics" level, though.

Ok, looks like I can skip the amp upgrade and invest my hard earned money on something more sensible, you guys are great!! :-) I'm going to order the SVS PB1-ISD tomorrow, PB10 will be here shortly so I hope the PB1 is not going to be on back order or anything. Next thing I need is a pair of heavy-weight stands to secure the M22ti, my 11 months old daughter is starting to walk, those curious little hands are all over the place!

Tom, where did you set the crossover point on your PB1? and which main speakers are you using? :-)

Good choice,a sub and not the amp.I think you will be amazed with the sub in the mix.

Tom has M60s. They're very nice. I've visited them. Him.

Sweeeet!! I just ordered the black color PB12-ISD(aka PB1-ISD) 5 minutes ago, Erik told me I should receive it on next Tuesday or Wednesday, can't wait to hear this bad boy eventhough I have no idea how well does it match with the M22ti. They have a PB12 in B-stock for $549, unfortunately it's tan color othewise I might of jump on it.

We're moving to another city by the end of next month so we'll have to start packing very soon, my wife is going to freaked when she sees this 78 lbs big box next week!! haha.

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I'm going to take my time to look around more, the Rotel RB-1080 appears to be a very nice 200wpc stereo as well, I'm still trying to decide if it's worthwhile to sink another chunk of money on something I might not need.

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I'd like too see what type of gear youll have in a year from now. Give me a buzz then, I might have my MF 3.2 cdp ready for grabs as I will be getting the next upgrades.

Peter? Can you tell Ben how well the PB12-ISD (aka PB1-ISD) matches the M22tis?

Saturn, I think I know why you bought the MF 3.2 CDP now, it's the curiosity and itch that have gotten the best of us, once you'd tasted a $1000 amp, before long you'll be shopping for a $1500 or $2000 upgrade, the same bug is going to work its way deeper and deeper to the core as long as financially allow.

BTW, I don't think any of us are saying that a bigger / better amp won't make ANY difference, just that you will probably see a small, subtle improvement from the new amp versus a huge, honkin' improvement from the new sub

Enjoy !!

Bridgman,

I totally agreed with you, that's why I'm holding off the amp upgrade now eventhough the little devil in my head keep telling me to go waste some cash, and I'm glad Dan and other reminded me....the extra headroom I get from a bigger amp is not useable or needed at the moment, If I must spend the money I think it's more sensible to upgrade my current M22ti to M60ti first, or just jump on the HT boat. :-)

M22ti + PB12-ISD = Seamless integration

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BTW, I don't think any of us are saying that a bigger / better amp won't make ANY difference, just that you will probably see a small, subtle improvement from the new amp versus a huge, honkin' improvement from the new sub

Enjoy !!

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On the contrary I found that smaller power amps with dedicated circuitry, quality parts like short paths and high power reserves on the power supply, minimal components within give the best presentation.
For example a Creek 5350SE 85w@8ohms or the CEC 3300 amp 60w@8ohms class A or Exposure 2010 50w@8ohms or Musical Fidelity A300 150w@8ohms can present a sound with more detail, better headroom and better soundstage than my Bryston 4B 250w@8ohms. I sold my Bryston and would pick up any of the amps I mentioned which also is much cheaper than the Bryston. Actually my older Bryston 3B 125w@8ohms sounded better than my Bryston 4B.

>>On the contrary I found that smaller power amps...

Well, um, that would be the "better" part of my comment...

I don't disagree. I haven't had a chance to listen to the very best amps, just "decent 200w/chan" vs. "built into the receiver" and I definitely preferred the bigger/better amp every time.

I just didn't want demasoni to buy a spiffy new amp and cut corners on the sub, when we all know he should buy that big honkin SVS that he's lusting after

You are now a Local .

>>If I must spend the money I think it's more sensible to upgrade my current M22ti to M60ti first, or just jump on the HT boat. :-)

There are just too many options, aren't there. I'm still trying to get my head around the differences between "best approach for HT" and "best approach for stereo". Even with the HK 630 (which I think has pretty good DSP code) there is still a real benefit to running in good ole stereo, mostly razor-sharp imaging and discrimination between the instruments.

The one interesting thing I noticed is that I can let the HK DSP high-pass the M2s and route all the bass to the sub (ie set 'em to "small") without seeming to hurt imaging much, while using the PSB's built-in high pass filter did seem to muck with the imaging a lot more.

Get the sub of your dreams. Be happy.

>>You are now a Local .

... and damn proud of it, let me tell you !!

You probably rarely push more than 5 watts while listening to your M22s. If the first watt isn't great, who cares about how many more there are behind it?

!

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I just didn't want demasoni to buy a spiffy new amp and cut corners on the sub, when we all know he should buy that big honkin SVS that he's lusting after

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I totally agree with you. A sub in his setup would immensely improve his setup. I was just putting my 2 cents about amps that I have auditioned over the years.

ok...as for the crossover, I really hope the highpass filter from SVS sub wouldn't mess with the sound quality, if the imaging is going to suffer then I'll either bite the bullet and build one myself, or forget about the highpass and run the M22ti at full range.

Dang it, is my sub here yet?!?!? I can't help but keep checking my email for shipping confirmation with tracking number :-)

For music, I would still run the M22s at full range... M2s need a bit more help from the sub than the M22s do...

I find things still sound a bit better in "large" even with the HK bass management; just that the difference used to be significant and now the difference is quite small.

Again, I don't really know why the x-over at 80-100 hz makes any difference in the first place... I need some better A/B switching gizmos to be 100% sure of what I hear.

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ok...as for the crossover, I really hope the highpass filter from SVS sub wouldn't mess with the sound quality, if the imaging is going to suffer then I'll either bite the bullet and build one myself, or forget about the highpass and run the M22ti at full range.

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Demasoni:

Well based on my findings I found that external crossovers work the best if one does not have a Surround Receiver with a sub out or if someone wants a full range stereo listening with mains and a sub. I use a Mirage LFX-1 active crossover which is hard to find but there are places that have em and they work amazingly. You can use low pass or high pass type connections. Low pass is okey but at low pass you can not really control the sound level. It is fixed. Using high pass is good because as you raise the volume level on the poweramp the sub volume level will also increase.

My setup is weird but works well. I wanted the full signal sound going to my speakers without any interferance. So I have the output of my mains going to my main speakers (like everyone else). But the bananas I have coming out of my poweramp are "stackable". So you can attach another set of speaker wires to the end of the stackable bananas and send the same signal to the active crossover high pass input. So also the crossover receives the full signal. From the active crossover I set it to where my speakers rolls off I'd say around 50hz and the signal coming out of the active crossover in both the high pass or low pass output is from 50hz and lower to fill in the low end. So the full signal gets passed to my speakers without any interferance. And the same signal get sent to the active crossover which only passes 50hz and lower to the sub...A nice full range of sound I get with this setup. The LFX-1 is used around $150-$250



See the out connectors of my power amp has WBT locking stackable banana connectors..RED+ & WHITE-. Connected to the end of the WBT are Ultralink locking bananas RED+&BLUE-.
The wires from the pair of WBT speaker wires(CAT5 network cables) go to the speakers. The pair of Ultralink speaker wires go the LFX-1 high pass input which is above my power amp. From my active crossover I have a RCA sub connector out to my sub.

Mirage LFX-1
http://spacelofts.com/h30/mini-IMG_2397.htm

Couldn't the Outlaw Icbm do the same thing as the Mirage,It's only $249 new and $199 from B-stock.

Outlaw works very nicely. BTW Saturn, neat cable arrangement. Not the rat's nest so many backsides look like.

Bridgman, what are those speakers? They look like M22s except for the MTM arrangement.

They are VP100s. Don't ask

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Couldn't the Outlaw Icbm do the same thing as the Mirage,It's only $249 new and $199 from B-stock.

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Yes thats an external crossover.

Hello Bridgman

Funny, but I considered using a pair of modified Meraks in the same way - Meraks were built by Axiom, have the same shape as your VP100s but use a pair of 6.5" drivers which I replaced with a pair of Axiom aluminum drivers. I like the Meraks for their horn tweeter. With upgraded caps and Axiom driver upgrade these Meraks sound terrific.

Saturn,

thanks for the great advice :-)

I was looking at some diffferent crossover circuit diagram and also checked out some external crossover and eq last night as well. My first concern is, active crossover tend to robbed power and they will color the sound to a certain degree depends on the type and brand of components I'm going to use. I do not know how the Axiom and SVS's drivers going to react toward different filter slope. If I'm going to buy one, I sure as heck going to need the complete list of components they used, If I build one from scratch, then it'll be extremely time consuming and going to cost $$$$$, a first order design(6dB/octave), it is affected less by impedance variations than higher orders, BUT...the drivers will be producing sound at frequencies that are very likely outside their upper or lower limits. At low powers (<10w) is probably not a major issue, but it becomes much more important when I'm pushing >50w. The HK3480 is 120wpc so it's going to be much worst, scratch that!! :-)

Ok, so I go 2nd order filters(12dB/octave), it's better at keeping unwanted frequencies out of the drivers, but it's more complex, and affected by impedance variations to a much greater degree, it's very tricky and not a good idea to simply use off the shelf caps and coils from...say partsexpress, the capacitance used must remain predictable and constant over time and power as well. The kicker is, the possible variations(especially those caused by voice coil temperature) can totally ruin the sound regardless of the quality of teh components or care in making this crossover network. The whole design task becomes even more complex and the tolerances more exacting as the order increased, so 3rd(18dB/octave) and 4th(24dB/octave) order filters are going to be a MAJOR pain in the arse!!

And I still haven't take phase shift and filter alignment into consideration, no wonder Axiom Engineers designed their drivers the way they are!!! After much consideration I think I'll stick with the KISS rule to be on the safe side.

That's why the M3Tis sound so good. The driver runs free, direcctly coupled to the amp, and the tweeter gets a really simple single capacitor and resistor.

Whatever the HK630 does in "small" mode is pretty good in terms of keeping the imaging, but I have no idea what that is other than knowing it uses the DSP, ie I don't know if the filter implementations are 6, 12, 24 dB/octave or whether any special type of filter was coded in the DSP.

My guess is that the HK uses 24db/octave because going through the HK crossover seems to raise the bar yet again in terms of how loudly the M2s can play "comfortably". With no high-pass they were not able to play as loud as I wanted without sounding strained -- with the PSB's 12 dB/8va they were able to play "just about as loud as I wanted" and with the HK's crossover I reach my limit before the M2s meet theirs. Crossover frequency was 80 hz in every case.

If you are OK with looking into an outboard crossover then I guess nothing needs to affect your sub purchase, ie you don't need to get any specific sub model in order to get the right high-pass filtering path built into the sub.

All I can say is that the best sound *seems* to be at the extremes... you get the best imaging (by a small margin) when the mains are getting an unfiltered signal, but you get the best SPL with a fairly sharp high-pass on the mains (matching the low-pass on the sub, of course).

DE, you may have been making the crossover question unnecessarily complicated and should indeed apply the KISS principle. To me that would suggest that you try the provisions that the SVS has before considering any type of external crossover. Since your 3480's outputs are unfiltered full range, use the sub's internal crossover to set it's rolloff(bearing in mind that, as Tom Nousaine has often found, the markings on the dial may be very inaccurate). Although the details aren't entirely clear(possibly ask Tom at SVS)my understanding is that the line level output on the sub has a 12dB/octave high pass crossover at about 80Hz to the receiver inputs. Feeding this into the amp ins on your 3480(with the jumpers disconnected, of course)might well give entirely satisfactory results without further complication.

The 3480 has a sub out but it is a full range signal.No need to disconnect any jumpers.

John, I thought the Highpass can only be engaged through the high level(speaker terminals) connection??

Wid, I believe John is refering to hooking up RCA from the source(ex: cd player) directly to the sub, then route another pair of RCA from the SUB preout to the 3480's main-in where jumpers connected. Now, instead of using the main-in shouldn't I use CD-IN or any other line level input instead??

Bridgman,

I believe the HK has 2nd order(12dB/octave), either that or 3rd order (18dB/octave) but definitely not 4th order.

I will try the 80hz highpass from svs sub and see how the M22ti sound with it. They're running in full range and don't sound strain at high volume so I might ended up leaving them the way they are.

Yes, this is a similar concept that is employed in several other mfg'ers designs as well - most notably Reference 3a.

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That's why the M3Tis sound so good.

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I don't mean to pick nits -- ok, maybe I do -- but wouldn't this mean that the M22s would sound better if configured the same way, with the woofers "running free"?

It seems the Pb-1 does do high pass filtering using the line level connections.I'll be darn.So what it seems Johnk is saying is to disconnect the jumpers on the reciever send the signal from the preouts of the reciever to the inputs on the sub then the outputs of the sub back to the inputs of the amp section.If thats the case thats a pretty nice feature my subs don't have.

Yes, Rick, what I meant was disconnecting the jumper between the 3480 pre-out and main-in so that the high-passed out from the sub would feed the 3480 amp section.

DE, as Rick also commented, SVS says that the line-level out on the sub is high passed, but doesn't give details. I've seen it said elsewhere that it's a 12dB/octave cross at 80Hz, but contact SVS for more info if you want.

I'd sent an email to Erik at SVS and still waiting for reply, I believe the PB1 has a 12dB/octave highpass as well.

The PB1 is on its way from Maryland to Virginia at the moment, and scheduled delivery is tomorrow afternoon...yayyy!! ;-)

Let us know what he says.

Just got the reply from Erik at SVS:


"Hey Ben;

You can use the 80hz highpass crossover on either the low or high level inputs/outputs. You can connect the sub in between the source and the receiver or between the receiver and the speakers. The only difference between the hookup methods is that the highpass filter on the low level inputs is 12db/octave while on the high level inputs it is 6db/octave.

Erik K"



I'll try the low level at 12dB/octave first, I think this is a little too steep, M22ti doesn't has much bass to begin with, anything below 60hz is weak so 6dB/octave should roll over easier and more natural sounding. I'll have to play around with different connection when I get the Sub tonight.

Ben, note that on receivers with bass management a 12dB/octave highpass is standard(24 dB/octave lowpass). It's likely that the line level connection would give slightly better results.

This afternoon the UPS guy was having a hard time getting the SVS box out of his truck, his face turned red and looked like he was about to faint when he'd finally carried it up the 8' stair to my door, my first guess...either this guy was a wimp, or this gigantic box weight a ton!! Heh, it was pretty heavy, shipping weight is 87 lbs but not as bad as I'd imagined. I brought it down to the basement and carefully inspect the box, didn't find any sign of it being dropped, so I'd unpacked everything, man this sub is extremely well contruct and seems like it can withstand some serious nuclear blast. This bad boy doesn't has the classy look of the Rocket UFW-10, but it's more like a good ol' muscle car packed with raw power under the hood.

I quickly dismissed the puny user manual and hooked up the cables and popped in a Dave Matthews Band CD, firing up the SVS solidified the muscle car image it has, it's getting late and I only had it set at 9 o'clock, that's plenty loud for now, had a chance to play the Darla taps scene and it shook the entire basement, everything on the wall was rattling and my daughter's pictures almost fell off, I'd jumped up quickly and turned down the volume!! If you'd asked me how does it sound so far, I'd say..."KICKS AZZ!!"
For now I run the Receiver's Sub preout directly to the SVS's low level input, and run the M22ti full range, everything sounds great so far but I will have to try the 80hz highpass some other time, I'm going to enjoy a couple more music cd with this new beast now. :-)

Congrats on the SVS!

I've got a PB1 (PB12) and M22s and keep them crossed over at 80Hz for music and movies. The only time I really notice a difference between running them full or crossed over is if I turn the sub off. Try it both ways and see what you like best.

So far the SVS PB1(PB12) matches extremely well with the M22ti, I still haven't got a chance to let the PB1 stretch its legs, some serious cranking will be done tomorrow after my wife and daughter went out. I'll have to calibrate it and map the in room FR as well, hopefully my neighbor wouldn't complaint much ;-)

I don't like the 80hz highpass on the SVS, the M22ti didn't sound quite right with the filter engaged, and they lost a couple dB. Plus the Sub is much easier to localized and pin-point even being crossed at 60hz to 70hz.

I'm going to leave the M22ti running in full range, in my room they have useable bass all the way down to 50hz and start rolling off at 45hz, then sharply decline at 40hz. they are able to draw most bass toward them, the sub virtually disappeared in my room even being crossed at 80hz, though I much prefer 70hz.