Regarding More Amplifier Wattage For A Given System

01-24-2008, 04:42 PM

If you're putting the same voltage into a lower impedance, the current provided by the amp has to increase. It's true that the opposition to the flow of current is less, but the amplifier has to spit out more electrons to keep the "pressure" (voltage) at the same place. There is no free lunch.

I'm sure that a well designed amp putting 100 W into 8 ohms is likely to sound as good as a well designed amp putting 100 W into 4 ohms. Also, if that output is at the same distortion figure (and all other things are equal) there shouldn't be any perceptible difference. Now, if one amp is running at 0.1% THD, and the other is at 1%, that's a different story. (Maybe - I've never done any empirical testing on such a thing. It may be that even that difference is hair splitting.)

Rant engaged:

Personally, (and this isn't to get on anyone's case in particular) I think the whole "headroom" thing is the new "myth with a kernel of truth that sounds plausible" in SR. Sure, you ought to have enough power for your boxes, but the discussion seems to be centered almost entirely around bigger amps into the same configuration of boxes, rather than adding more of the same amps AND boxes. (That's how you really get more PA.) If I had "2 over 2, with 400 watts per box," I'm sure the results of going to "4 over 4 with 400 watts per box" would be better than keeping the 2 over 2 and upping the power to 800 watts per box. I'd be less likely to blow something to bits, and I would be able to move a greater volume of air. I would have more headroom in the whole PA, instead of just a single component.

Rant disengaged.

I guess my whole point boils down to "Does the rig sound bad?" If so, then is it really because the amp is running close to rated power? If the rig really is disappointing, my bet is that there multiple factors in play, with much more to do with the issue than how close to rated continuous power the amp is running.

As always, just my opinion.