I recently installed the sony XAV-AX4000 from trail seven. It came with the wiring harness and everything i needed. For some reason there is no bass. I have tried everything, changed all the EQ functions checked connections, nothing.
I plugged the old stock unit back in and bass worked fine.
My 17 JKU does not have the amp under the steering column, did not even have Bluetooth.
Do i need to buy an amp or is this a head unit issue? Anyone else have this problem?

 

Welcome to JK Forum MOpinion is Call Trail Seven ask for Tech Assistance..

 

tried that this morning. They are supposed to call me back but haven't yet.