just a quick question, hopefully i can get a straight answer. I've got an amp that can put out 500 watts at 8 ohms (per channel), or 850 watts at 4 ohms (per channel). Which would be louder? My automatic sense is to think the 850 ohms would be louder, but then it may be that the increased resistance of the 4 ohm cabinet would make less 'efficient' use of the power, and their loudness level would be similar. So which would be louder? I'm looking at getting a new 15 or 18 sub and trying to figure out which I want to go with.