i guess, lol..... so, i partied a bit last night, and recovered today, lol. anyways, as you stated, you were only pushing a 60 watt, and were not taxing the power supply, save for full, possibly clipped signal. also, you did nothing for imp. rise. i'll admit, i also do most of my tuning by ear listening for both signal distortion, clipping, and driver distortion. after all, you are tuning it to be heard by ear....... i also can't help but to use paper and a simple calculator to build enclosures, lol. anyways, the power level we are talking about here, you are going to see more difference once it begins to start passing some real current, both in supply voltage drop(unless you have your alt and such bucked up to prevent any, which would be overkill in this install) and, i suspect, output rail voltage. adversely, imp. rise, is going to make that voltage pass less power (measured in watts) via current drop. if your feed signal, the hu, begins to clip at 3/4, and you set the gains to that point, any signal greater will be playing a clipped/distorted signal, even if the amp is not actually clipping, which, in turn, will lower the actual power handling of the sub itself. so, i suppose, in the end, you could set it that way, then your 750watt driver will be protected from going over it's now 550watt rms limit, but i would rather feed it a clean 750. i'll still go out and clamp to see the real numbers, just need a couple days to go do it...
