http://www.caraudio.com/forum/showthread.php?t=279633
If i also may add I posted the Actual Release date on the 2200... READ.....
The Knob is a really neat feature on the amp.... When you set the amp up via correct gain structure/ Lowpass/ SSF etc... You Plug this lil thing in and you have what is called an Actual Gain Control In which it adjusts the actual GAIN on the amp up or down REMOTELY... It IS NOT A BASS BOOST KNOB!!! lol... Say you have your gain set a 1/2 of the way up for example it will either increase or decrease the gain on the amp to the point were it is set and no more.... NICE!!!
The AQ2200D doesn't have the crap features like "BASS BOOST" Etc...
It has what all D class sub amps should have... A GAIN, CROSSOVER, and SSF...
That way you can spend the extra money on making the amp better or more eff. instead of wasting it on pointless and damaging Feature's a lot of people use that end up screwing shit up...