S90i subwoofer


In-Wall (2×4) RTL Subwoofer

The S55i can be mounted in-ceiling, in-wall, under risers, in closets, and on floors. It is a rare example of a custom-centric design that offers competitive results versus the finest freestanding options. The S55i is a strong performer, featuring the quickness and tonality all our RTL subwoofers are known for, with bass extension to 40Hz. Its size makes it well suited to being custom-installed and thereby hidden behind its small paintable grill and bezel.

The Regenerative Transmission Line®

Regenerative Transmission Line® designs yielded the unique combination of high sensitivity, high output, and low distortion with the uniform and extended response we required. The result is extraordinary power and punch combined with a remarkable level of quickness, tunefulness, and realism.

Key Features

In-Wall (2×4) with Grille
Regenerative Transmission Line® design

Highly Detailed & Dynamically Accurate
(4) Custom Designed High-Output Long throw 3”x5” Woofers

Optional floor/ceiling extension port kit available for venting into a space from an adjacent room, attic, riser, ceiling, and or floor.

Flat Frequency Response Across a 40Hz-80Hz Operating Range
(4) High Operating Woofers
DSP Required
(1) Channel of Power Amplification per Subwoofer Required


Frequency Response40Hz – 80 Hz ± 3dB relative to the target curve
Impedance8 ohms
Sensitivity90 dB / 2.83 V / 1m
Power Handling, Peak240w
Maximum SPL112dB / 40Hz / 1m
Shipping Weight43 lbs. (20 kg
Dimensions – HxWxD54” x 15.875” x 4.25” (137.1cm x 35.9cm x 10.5cm)


PDF File Icon

S55i Owner’s Manual

PDF File Icon

S55i Dimensions (PDF)

DWG File Icon

S55i Dimensions (DWG)

PDF File Icon

Optional S55i Port Extension Kit (PDF)

PDF File Icon

Optional Port Kit Installation Manual

Related Products