Installed new deck - sub doesn't hit

I recently upgraded from an Eclipse Minidisc unit (I think it had 4V preouts) to an Alpine CDA-9815 unit with MP3 capability. For some reason, the subwoofers aren't hitting nearly as hard as they did when I had the Eclipse deck, even with the sub level turned to the max (15). I adjusted the gain higher, but it still doesn't hit like it used to. Thanks in advance for any help!

My suggestion would be to go over all your wiring and check to make sure everything is properly connected. Could just be your rca's not properly connected.

The RCA's for the sub are connected as tight as can be. I even unscrewed the connectors to make sure the wire was contacting the metal plugs properly.

Well you can always try another set of RCA's. But be sure to check all connection on the back of the headunit. If it isn't this then i will assume it will be something to do with the crossover frequency on the headunit.

that would be it. Crossover in the headunit.  My pioneer was like that till i played with the insystem crossovers. I need quality equipment, feel free to donate.