I am trying to fine tune my ststem and seem to be getting somewhat frustrated. I have a KDC-MP44U HU, Polk db6501's and an Alpine Type S 10 sealed. Powered by a Kenwood XR-5S - bridged to 160 watts X 2 to the Polks, 350 watts to the sub. The Polks are sounding pretty close to where I want them, but I don't have any punch from the sub. It's there, but very quiet. I have tried adjusting the input, crossover points, and have the sub level on the deck all the way up. Still not much from the sub.
Any ideas?

 

Go ported and more power, that would help.

 

might not be enough sub to begin with..you might be searching for a higher powered sub also is it sealed or ported? willing to make an adjustments in gear to satisfy yours needs? what kind of car?