Rockford Fosgate Prime R2S Series 12" Shallow Mount Subwoofer closeout run back speakers off the

run back speakers off the rear channels and run subwoofer(s) off the 5th channel

The Massive Audio Hippo84v2 should be at the top of your list when it comes to a well made

High-level (speaker level) inputs accept the signal from the speakers

1 is your best bet

Midrange Mounting Depth

Rockford Fosgate Prime R2S Series 12" Shallow Mount Subwoofer closeout run back speakers off theWhen you have no space for bass, our R2 12" shallow subwoofer can help satisfy your need for low frequency music. These drivers can fit in tight spaces due to an elevated motor structure that reduces speaker depth. Mica injected polypropylene cones make sure bass notes are clean and accurate. Stamp cast baskets feature spider venting typically reserved for traditional depth mounted models to keep the motor cool! These shallow subwoofers are optimized