Ok...I have found both of these for sale for the same price, $350.

Which one should I pick up?

*USED* Velodyne CT-150. 250w RMS amplifier, 15" driver, 72lbs, favorable reviews everywhere. Basically flat response from 25Hz on.

*NEW* Audio Pro Avantek. "400w" amplifier (unknown if RMS or max), 10" driver, I can't find any reviews, don't know about frequency response.

This is for home theater us 75% of the time, music 25%. I am leaning towards the Velodyne since I know more about what I'm getting into. But, maybe there's more I can find out.

I never heard of avantek but other may have. But I'd also have to choose the Velodyne as a choice if that is the only two you narrowed it down to.

That is the only two. This is to replace the following:

KLH 10" front subwoofer (100watt RMS, front firing, cheap, bad cabinet, port noise)
Onkyo 10" rear subwoofer ("150watt" RMS, down firing, cheap, bad cabinet, port noise, weak driver, boomy)

I think the one Velodyne should do the trick quite nicely, but the other could too. But I think the better low frequency extension of the Velodyne will be the plus, as asthetics and size mean nothing to me. But, it is nearly 10 years old. The other one is new.

Picking up Velodyne today.