Axiom Home Page Forums General Discussion Home Theater How much power do I need - m60 measurements

2X6: if you will read the FTC Regulation that John referenced, you will see that he is correct in what he says.

I'm not saying that the FTC Regulation is right, wrong, or indifferent, but it was an ATTEMPT to force manufacturers to more accurately specify their gear. Read some of the FTC commentary leading to the Regulation. You may find it quite interesting.

I'd really like to see the FTC do the same sort of thing with speaker wire/ cables. If such a thing were to happen, watch all the charlatans cry foul!!!!

Back to the “how much power do I really need question”.

My M80’s driven by a HK 7300. A pretty respectable AVR by anyone’s standards for power capabilities. I have a set of M22’s in parallel as my center. QS-8’s, and an EP 600. All this is an area that is 10’ X 10’. According to your calcs and the hard line that John has always taken here about the “how much power do I need” topic, any ol’ AVR rated at 50 watts per channel or less would be more than adequate. Right??

I don't think so.........

Last night the little lady was out so my son and I watched a movie the way we like them, “movie theater loud”. (great kid, takes after his old man)…….We watched Spawn (his pick this time). I bumped the volume up to what sounded about right, which just happened to be -10 on the AVR. The AVR goes from a -80 to +8. (It was roughly 85%). Out of curiosity, I pulled out the RS meter just to see how loud things were getting. On the C setting, slow response, normal dialog was around 75 db. Gun fights and action scenes would get up to 95 db with an occasional spike over 100 db. Just for the hell of it, I ran the volume to max, and guess what; it didn’t get all that much louder. (the EP 600’s volume is just about ¼ up).

That was watching a movie………………..

Listening to stereo is completely different. I don’t know how loud it’ll play. Well over 100 db’s at 12’. That’s as far as I’ve had it.

You can’t just say “a 50 watt AVR will be just fine”. It very well may be just fine for YOU and at YOUR listening levels. But it sure in the hell wouldn’t cut it for ME. And it may not cut it for half the folks asking the question either.

mdrew: I think that you just verified my above analysis that seems to indicate that for loud listening, you need more capability than 100 watts of peak power, at least for the fronts and center. It may be that the peak power capability is far more important than the average power capability. At least, that is what I am currently thinking.

I, too, was playing around last night with the SPL meter. I find that anything averaging 91-94 dB SPL on the meter is just too loud for me to enjoy. 87-90 dB SPL is about as loud as I would like to listen. But, that is just me.

Boy, I'm glad I skipped this thread...

This has been a great thread. What don't you like about it?

I agree with you fellas. I usually listen to movies at 72db. Music, a bit less. Most of the music I listen to is jazz or female vocals, so it tends not to be too taxing on the amps. My Thiel CS 3.6 fronts are 4 ohm power hungry monsters, so I use the Yamaha Monster M-80s which are rated at 330 wpc, continuous 4ohms, at 0.02% distortion, Dynamic power (1KHz/4ohms) 640 wpc; Signal to Noise ratio 127db!!!; Damping Factor (1KHz/8ohms) 250. I figure they deserve some headroom. Great combination with the Yamaha brutes - power for the power hungry. Axioms are efficient. and the 8 ohm speakers at less than ear-splitting volumes don't need much power, but if you have a high quality amp (sounds good), then the more the better.

As to the FCC regs which permit manufacturers to rate multichannel amps on a per channel basis when the output is only accurate when 2 channels are driven is simply a license to proliferate false and misleading advertising. If a mfgr rates a 6 channel receiver's amp sections at 100 wpc, and when 6 channels are driven it only puts out 31 wpc, then anyone who relied on the 6x100w rating has been deceived. Simple.

Johnk,

Thanks great info. So is the blind listening comparison of amps. This stuff is just gold when trying to decide how to spend your A/V money.

My room is a little smaller than Gena's and probably a lot more reflective, so I would expect to get to ear splitting without strain or distortion.

I am beginning to think the "strain" I am hearing at loud but not exceeding loud volumes in some material may be due to the material. When I turn down the volume I think I am hearing it when near the speaker but not in the listening position. Maybe just a hot mic, close mic, or saturated mic on some of my recordings. They are modern recordings and otherwise well done so I did not notice. Nora Jones "Come Away with Me" is the CD I heard this on most. Not sure if there are any fans with amps in their system. Wish I had an amp. to compare.

Mike, you may have confused me with another poster; nothing like that was said.

A short course for the technically challenged like myself.
Link

As luck would have it I did get a loan of an Anthem 5 ch 225 W rms amplifier to compare to my integrated Yamaha RX2400-V 125 W x 7ch receiver's amps.

In each case the "distortion" or harshness I heard was on the recordings. Both the Yamaha and the amp play to, FOR ME(and others listening), painful levels with no discernable distortions or differences. I am not claiming there wasn't any, there obviously is if you look at the specifications or measure, just reporting that I could not hear them. I am not an "expert listener" or an audiophile just posting my experience in case it is of use to someone.

I would still go with separates if it was in the budget, but my next purchase will be rear channel backs if I start getting 7.1 DVDs or an HD DVD player.

My setup
M60ti
VP150
QS8
Velodyne DLS-4000 Sub
Yamaha RX-V2400
Room is 15 x 18" open at one corner and part of one side. Carpet but wall surfaces are fairly reflective. Listening position if 12'.