I know they don't, it's just that my LP 2.2HV should only be run @ 4ohms bridged, but really prefers 8ohms bridged. I know with impedence rise it probably wouldn't matter, but I'm not taking the chance of ruining this amp. I already paid to have it repaired once.3 ohm is pretty weird, but these really don't need a ton of power to get moving. ttt