QUICK message about wattage in small-med rooms

The question remains just how accurately your McIntosh meters can keep up with the actual power output of the amp on peaks?

Cheers,
SB

Sure, one can quibble about that....

But the OP's point still stands for the vast majority of home theater uses.

It is true, an alternative is to try other amp with meter, I had an Accuphase power amp before and it's just like what the first poster said, only a few watts during most listening session and may be 20 or 30 at crescendos or what not, yes of course different listeners, systems and music might use a whole lot more, and transient might demand far higher number but I'd think the message is most of the time for most listeners very little power is used, YMMV.

Yes, obviously average power will be much lower than peak power. I see the same thing when I hook up a kill-a-watt. On spikes, I seem to recall I rarely went over 100 total. When it's not spiking, I am drawing not much at all.

Which is why I think someone implied that the peak draw may not be visible, as it may last for a very short period of time.

I used to have a program I wrote that read WAV files, and measured peak to average. At least 10 dB. Which calls for 10 times the power. I had no nice way to estimate how long those peaks lasted. Maybe a meter can't pick them up.

I think even some of the amp with meters have a function to capture the peak usage, may be that would show be useful to interested users.

To be honest its just not very sexy to sell you a 50w amp that weight 2 tonnes and cost half your mortgage

I didn't mean to imply that your meters were defective, nor do I doubt that you listen at a volume that only averages 1-3 watts continous. What I meant in my first post is your meters are probably not physically capable of measuring instaneous full power surges. That's the nature of the beast. But what happens when your source material goes into "overdrive" for a split second during an action scene, for example? Remember that when a common HT RC system is in use (Audyssey, etc.) it is common for it to boost by as much as 9dB depending on factors like the room, among other things. Just that 9dB of boost alone requires an 8X increase in amplifier power regardless of your average volume setting.

I'm not trying to argue with you. I'm only mentioning something that you don't seem to be aware of. Sorry if that's too much for you to handle.

I'm done here.

Cheers,
SB

Wow I didn't even think about equalization boosting the signal. That changes everything!

3 watts for average level. If he needs a 20dB peak, that's 300 watts (limit of his amp if it has no headroom (tightly regulated power supply)).

I imagine it's more complex than for eg a 3dB boost to double the total watts. For instance, if that boost was in a bass frequency, and it was using 200w for that "note," then we'd double 200w to 400w, and so the total power draw might be 200w higher instead of 300w higher, for a total of 500w. If the boost is higher up, where pre-eq it was drawing 20w, then the 3dB boost adds another 20w, which is more easily handled.

Definitely suggests that at higher volumes (like over -10dBfs) and low-to-medium sensitivity speakers, one should look to getting a little more amp, and make sure those speakers have decent peak power handling. The OP's CM9's can probably handle 800w peaks, so less of an issue for him.