Exhaust to boomy and loud

[newsh]

How about a Miltek rear box? I loved the sound of my coupe with the Miltek and the 3" system on the avant is fine, both of these were from DP back though but without cats (the avant cats are empty) I guess the 1 into 2 and back quietens things down a fair bit..
My understanding is that twin outlets help to smooth out the resonance which causes booming because of the different lengths as they turn the corner. This applies to a coupe box mounted across the back of the car.

[Rusty]

I have 3" DP, 100 CPI sports cat and single back box. The 3" pipe runs to the back seats and then drops to 2.5" to clear the rear diff. The change in section does reduce the resonance of the system, at the expense of flow but for my setup, it works well. Measured about 90dB at ADI so easily withing all trackday limits too