Very nice amplifier. Here are my $.02 which will be further enhanced when I get my new box so my DD9512 gets hella loud.
Price: $255 + shipping on eBay.
1500w RMS @ 1 ohm it's actually a tad higher than that, but great power
Subsonic Filter adjustable from 15-35hz I believe. Works great.
0-180* Phase Adjuster, haven't used it yet.
.2-9v Preout adjuster - works great, I set it to ~2v, which is what my H/U puts out.
Line-Out RCA jacks - Nice, you only need to run one set of RCA's to the trunk, because you can run RCA's out of the amp - Full signal - and then to your other amps.
Low Pass Filter - Adjustable from 35-250hz I believe. Works great.
Remote control 0-18db gain. Very nice, mine is mounted by my dash.
Power wire terminals accept 4 awg wire. Very handy. Speakers accepted my 12 fine, and will probably go to 10 awg. Remote wire handles basically the same as the speaker wire. Albeit I am running a small wire there.
The blue hifonics logo on the amp is very nice. It's actually pretty bright.
It pounds. I have no scientific data. No numbers, nothing. But it pushes my subs hard and gets loud. Very clean power even in rapid hitting bass. Very clean response in sweeping bass notes as well.
I will edit this post in a few days after I get to hear my DD 9512 in the new box. I will also make sure the specs are correct in the meantime.