i just got the alpine pxa-h510, and it has plenty of control. I have it hooked up to my 9857 via ai-net, but the processor has a 'changer in' ai-net connection, so you want lose that. the thing I like about it most is the fact that the volume is still controlled with the HU, not the processor. As of now, I only change the sub level with it, as I havn't got around to playing with ti much, but it is a nice, solid processor. Heres the specs if you interested:
Parametric-EQ Number of Bands
Front: 4, Rear: 4, Center: 2, Subwoofer: 1
Equalizer Center Frequency Range
Front and rear
Band 1: 20/25/31.5/40/50/63/80/100/125/160/200/250/315/400/500/630 (Hz)
Band 2: 63/80/100/125/160/200/250/315/400/500/630/800/1k/1.2k/1.6k/2k (Hz)
Band 3: 200/250/315/400/500/630/800/1k/1.2k/1.6k/2k/2.5k/3.2k/4k/5k/6.3k (Hz)
Band 4: 630/800/1k/1.2k/1.6k/2k/2.5k/3.2k/4k/5k/6.3k/8k/10k/12.5/16k/20k (Hz)
Center
Band 1: 100/125/160/200/250/315/400/500/630/800/1k/1.2k/1.6k/2k/2.5k (Hz)
Band 2: 315/400/500/630/800/1k/1.2k/1.6k/2k/2.5k/3.2k/4k/5k/6.3k/8k (Hz)
Subwoofer
Band 1: 20/25/31.5/40/50/63/80 (Hz)
I got mine for $150 used off
ebay, its a few years old, but is in mint condition.
Plus, its got Dolby Digital!!!