Upgraded speakers - sounds flat!


Jul 2, 2023
Hey guys, I’ve just replaced my HU with an DSXA410BT x 4X55w and replaced the factory speakers with in phase xtc 13.2 in the front and xtc 10.2 behind the seats. I didnt touch the tweeters.
My Z3 doesn’t appear to have and amp or factory Sub. There was an amp on the passenger door car. I’ve completely bypassed this by bridging the wires, and leaving the power etc in the factory plug. I’ve also used sticky foam around the seals of al of the speakers to ensure tight seal.

It sounds terrible. Completely flat, bass isn’t there, it sounds flat. Stereo EQ is set the best it can be. How have others overcome this issue? Would love a Sub, but don’t have the ability to make a custom box, and really don’t want to cut into any of the plastic!