Sub and Amp question
 

Ok i have one last question before my sound system is complete. i have a pioneer avic x930 bt with the expensive wire harness and pac. i have a mb quarts amp (monoblock) 1500D and one kicker L7. We wired everything up right get power to the amp. put the 2 RCA from the amp input to the SWL and SWR on the back of the AVIC. the problem i am having is the sub is very quiet you can barley hear it. We know the sub is good tested it in another car and I got the amp back from the shop and they said its good. Some one else was telling me i have to use a y splitter, since thats why its so quiet. i was woundering doest the amp or sub have to be hooked up to the other amp and sub thats in the car? Or is there something im missing. This is the last thing i need to do to get this all good to go.

Have you checked the subwoofer settings on the radio? On Pioneer headunits (I have one too), there is a "Subwoofer Level" option that goes down to -24dB and at that point, you cannot hear it... This could explain... Or maybe you're not in phase? Try to reverse phase on the headunit! If this does not work, then I don't know what it could be :S Hope this will help!

make sure you have a good ground!!!!

Alright i will try this out tomorrow. Also the ground is on the same one the battery is on in the trunk i figured that was good enough for the amp.

on the mono block amp unplug 1 rca leaving just 1 plugged in and see what happens. It will either get quieter or louder. if it gets quieter then pull the sub from the box and hook up just one voice coil and again see if it gets louder or queiter

Check and make sure one of your voice coils isn't wired up backwards. I had a friend who had this issue with a JVC 15 and he claimed his amp wasn't big enough so I hooked mine up to it and when this sub would just barely move, my lights would dim horribly and they wouldn't even do that with two 15s. Pulled the sub, rewired it, had the box sitting on the ground. It now was bouncing box and all off the ground. The voice coils were working against one another.