Axiom Home Page Forums General Discussion Home Theater Value Reciever for Amps

Based on the channel levels you posted, and playing at 0dB, you may be driving your Denon into distortion. How many dB above zero can you go on that Denon? Careful you don't blow your ears or tweeters. Maybe disconnect your speakers when trying this.

Speakers thermally and/or mechanically compress if over-driven. If they are compressing, a larger amp will not help.

P.S. I see Bridgman has given you a very complete answer.

Taking consideration Bridgman's response, there is merit in tackling the electronic side of the equation first and see if an increase in power will produce a dynamic headroom improvement in the performance of the M22's and QS-8's. At a minimum, if you were to get larger speakers, you would need to this upgrade step as well.

The Emotiva route I mentioned is a popular one with those familiar with internet direct companies and willing to give them a shot.

I'm a big fan of NAD products and have a stereo amp in the living room. I would not hesitate to recommend any of their AVR's or Separates (T-7x7 series or M series).

On a budget? I've owned Denon and Yamaha in the past but much prefer my current Onkyo. Honestly though, it's a civic/accord vs corolla/camry vs sentra/Altima argument. They are all about the same. The higher end of their models tend to have a bit better build qualities.

Another interesting puppy on the market is the ARCAM AVR550. A bit pricey but I've heard good things. In the same vein, Rotel used to be a big player and the Rotel RAP-1580 would be a cool piece of gear to have... I would also consider the Anthem MRX720.

Dog I hate this hobby!

In your original post, you said you are hearing "strain". Strain is thermal and/or dynamic compression. If on the other hand you are hearing harsh highs, that's an indication of harmonic distortion from your Denon. Try to establish the root cause. You may want to talk with Axiom about it.

I miss the good old days when we had peak-reading VU meters and clipping lights. This whole "customer is too dumb to be told what is going on" thing really irks me.

That said, I do have to acknowledge and appreciate Axiom's "give them so much power they don't need clipping lights or VU meters" approach.

I've been thinking of building just such a thing. It would present practically 0 burden to the amp and have an app to show you all kinds of things like voltage, current, average power, peak power, waveform, harmonic spectrum, etc etc. It would be available in multi-channel.

Perhaps "strain" wasn't the best word. During loud passages it just feels like the dynamics aren't there... It sounds like the musical power is falling short of what it should be.

... It feels "not quite there". You know what I mean?

I'm watching Gladiator (for example) and just feeling like there should be more sound!

I do know what you mean. You've moved from an 800 cu ft room to over 7000 cu ft. And you have puny QS8s and M22s. I had QS8s and traded them in for QS10HP and I am so happy now. My space isn't as large as yours but it's not puny either at 4200 cu ft. My Onk, M5, QS10, EP800 and VP160 - all v4 - completely fill my space. I can't say I feel the rushing of wind or anything like that but my ears give out long before my system does. That's at around 30 to 40 Watts average peak power so it's not anywhere close to taxing my Onk. BTW, I can't say enough about v4 if you read my posts and product reviews.

Hi snazzed,

I just wanted to add the importance of having available dynamic headroom. Virtually all receivers and even many separates that use a switching power supply have no dynamic headroom. The power supply is sized to the RMS continuous power rating of the amplifier. In music and movies it is the dynamic peaks being clipped or compressed that cause the loss of performance at higher levels, which can be reached very quickly in large rooms. A few numbers to consider which Bridgman has already touched on; every time you double the distance from your speakers you lose 6dB, dynamic peaks can reach 12dB or more in music and movies, but you only gain 3dB for every doubling of the wattage of the amplifier. You can see how quickly you need a lot more power. A linear power supply with lots of storage capacitance will allow the amplifier to produce multiples of its rated power for short periods of time. All of our ADA amplifiers have this capability. So my suggestion would be to get a receiver that has pre-outs and not worry too much about its rated RMS power. Then get a separate amplifier with lots of dynamic headroom to power the front three channels. You can power the surrounds either from the receiver, by adding more channels to your main amplifier that is running your fronts, or by getting a smaller multi-channel separate amplifier to power the surrounds. There is a lot less dynamic power required for the surround channels.

Snazzed, I want to give you some numbers from my system so you can put Ian's feedback into context.

I have an Onkyo TX-NR818. It's rated 135W/channel to a similar standard as your Denon. I recently did a test with a 200Hz tone via my M100v4. You know my room size and how far away I sit. My room is on the lively side so it's not too damped. As I mentioned above, I normally listen between -10 and -20.

At -20, my Onk is putting out 0.2W and at -10 it's 1.75W. I can turn my Onk up to +13 but for the purpose of this test, I turned it up only to +10 because I was worried I might blow something up. At +10, the Onk was putting out 173W to EACH M100. I doubt it was a clean 175W - I don't know because I had hearing protection on.

With that as background, let's say the sound is only clean up to +4 which is almost 45W. I think it's quite a conservative assumption to say it's clean up to a third of its rated specification. So even at -10, that leaves me with 14dB of headroom. In a 4200 cu ft. room and 13 feet away from the mains!

Your Denon is rated at 90W so let's say it's only clean to 30W. If I use my Onk/M100 data as a guide, when you set it to 0, that's leaving you with only 3dB of headroom. That would mean dynamic content is getting clipped. Perhaps you're not hearing harshness in the highs and instead perceiving that "it's not there" because Denon has done a good job on its soft clipping circuit.

Now that I've gone through this analysis, I can recommend you ought to give an ADA a try.

P.S. Make sure you don't have something silly like "Night mode" on.

I will ask the question, When you say it is not loud enough, are you talking all frequencies or what?

I kind of remember Brigman going on about his experiment with speakers and how moving the couch made the sound improve. Throwing more power into a standing wave will do nothing to improve the sound. Have you tried moving the speakers around in the room (even non permanent) just to see if you are getting bad sound from the room rather than lack of power or speakers.