pdx, what i was trying to highlight was that speakers are not resistive loads...but they get close to that if running in sealed enclosures down toward the single digits. the left side of my chart (a ported option) shows power goes to zero and peak around the port tuning point. the left side of your chart (typical of sealed) shows power going to 100% as you head toward single digits. i had a low pass filter in place which would be typical in either case.
"I'm one of the people that always shoots for a 4 ohm load in my HT. always have, always will. If that means I have to buy an extra amp or 2? then so be it. It's just so much easier on your gear."
n8, is there any difference between running at 4 ohms and at 2 ohms if the current is limited to the same amount?
doublewing, i'm not sure how much low end boosting that the other guys are doing with their sealed subs. each +3db or so of boost doubles power requirements on the low end. so if someone were running +9db of low end boost to help make the frequency response flat, that is 8 times that power requirement on the low end. so even if two guys are both at "reference level", the guy with +9db low end boost to get there needs 8 times as much amp power.
archaea, related to the question for n8, i'm increasingly thinking that so long as the amp doesn't detect it as a short and shutdown, running below the recommended impedance load is fine, so long as either the signal is kept low enough not to pull more current than the amp can provide or it is limited internally. for practical purposes what this means, i think, is let's say you have an inuke 6000dsp and four drivers that are 4 ohms and you want 1000 watts per driver. as you point out, no apparent way to make this work since the amp is not bridgeable. however, just paralleling up the drivers for 2 ohms per channel, then setting the limiter to 1000 watts (or setting the voltage to 0.707 x the stable voltage into 4 ohms) will pull the same current and produce the same power--1000 watts per driver--which is what the amp would be providing if you were to have four 8 ohm drivers, 2 wired in parallel on each channel. the problem would be if you tried to run the full voltage swing into 2 ohms, then too much current gets pulled through the amp as it would be trying to provide 2000 watts per driver.