S90 fc V2


C20 Audiophile Top 25 of All Time AwardSound Image AwardS90i CE Pro Best Award Finalist

RTL Subwoofer with Port Extension Kit

The S90-f/c highly efficient design yields fast, dynamic, articulate results with accurate timbre. This is a high-end subwoofer solution for customers who desire no-compromise performance, but prefer the aesthetic benefits of custom-installed, hidden loudspeakers. The S90-f/c has superb performance characteristics, which include a flat response to 20 Hz with usable in-room energy down to 17 Hz, outstanding dynamic capability, and accurate timbre reproduction. Three versions are available: S90i (when an exposed grille is needed), S90 basic-port (when you are going to place it behind scrim cloth/acoustic fabric and you do not need a grille, and S90-f/c (when you need to extend the port of the S90 from the attic, crawl space, or an adjacent room).

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 (2×6) with Grille
Regenerative Transmission Line® Design

Highly Detailed & Dynamically Accurate
(2) Custom Designed High-Output Long Throw 5”x7” Woofers

Three versions are available:
1. S90i for when an exposed grille is needed
2. S90 basic-port for when you are going to place it behind scrim cloth/acoustic fabric and you do not need a grille
3. S90-f/c for when you need to extend the port of the S90 from an attic, craw space, or an adjacent room

Flat Frequency Response Across a 20Hz-80Hz Operating Range
(2) High Operating Woofers
DSP Required
(1) Channel of Power Amplification per Subwoofer Required


Frequency Response20Hz – 80 Hz ± 2dB relative to the target curve
Impedance4 ohms
Sensitivity93 dB / 2.83 V / 1m
Power Handling, Peak1000w
Maximum SPL123dB / 20Hz / 1m
Shipping Weight65 lbs. (30 kg)
Dimensions – HxWxD92.75” x 15.875” x 6.125” (235cm x 40.3cm x 15.5cm)



S90-f/c Kit Installation Video (using older metal tube)

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S90-f/c Owner’s Manual

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S90i Dimensions (PDF)

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S90i Dimensions (DWG)

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S90-f/c Port Extension Kit (PDF)

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S90-f/c Port Extension Kit (DWG)

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Port Kit Installation Manual

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