This time I picked up a clean Eosone RSP-912 for $180. Don't have a ton of specs on it, but I do know Eosone was essentially Polk. This subwoofer ALSO hums at higher levels. This leads me to a question on subwoofers in general - do they ALL hum if you turn the level up? I have it around 8 or so with the crossover around 65-70 hz or so. What I am doing right now to eliminate the hum is turn the level down to about 6-7 and turning up the subwoofer via my preamplifier (Set at 4). I think the Energy was probably the same way - if you turn the level way up it hums. The guy is willing to let me take it back to him if I'm not satisfied with it however I feel obligated to let him keep a little of the price ($10 or $20) for letting me try it out. This same guy had the full Eosone setup, including two tower speakers, a center channel and two "rears" - they had poly tweeters on the left and right side angled outward and what appeared to be a 6" driver in the middle. They seemed setup for use in a THX setup as 7.1 speakers.
He was selling all of it, sub included for $400 claiming he spent $2k on it all new. I don't have much need for anything but a sub but he'll let me buy the speakers if I like. Didn't know much about them though or if they have any real value resale wise.
Anyways this subwoofer seems very decent in bass. Most important - no pop on power off! Not even a little bit! I knew this was not normal. I think I'll record a video of what the Energy does to give a better idea. It's a manual push in switch whereas this Eosone is a vertical toggle switch of either on or off. Hell, it seems worth it to me just to get rid of that lousy *** popping which scared the hell out of me. Can anyone provide more specs on this sub? Here are pics from a similar sub I found online: