Cambridge Audio S90

Compact powered subwoofer

  • Cambridge Audio S90

    Front with grille attached

  • Cambridge Audio S90


  • Cambridge Audio S90

    Front with grille off

Item #: 779S90GR
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Our take on the Cambridge Audio S90

by Dave Bar
Cambridge Audio

Why add a powered subwoofer?

A powered subwoofer gives you bass you can feel as well as hear. Our customers love the depth and impact their subs add to music and movies. We hear comments like "it brings out sounds I didn't know existed in discs I've watched a million times." Powered subwoofers aren't just for big bass that rattles your picture frames; they can also deliver tight, accurate lows. If you haven't shopped for a powered sub in a while, you might be surprised at how small they get. Look for an ultra-compact model if you want to tuck your sub away under an end table or in a corner.

Complete your system with deep bass

The S90 may be compact, but it can certainly pack a punch when needed — all the way down to 35Hz. A built-in 70-watt amplifier helps it deliver some serious low bass performance. It's a perfect match for Cambridge's S-series speaker line, and works best when used in a stereo music or home theater system along with the S70 floor-standing speakers, S30 bookshelf speakers, or S20 bookshelf speakers.


Read more

Designed and engineered with passion

All of Cambridge Audio's S-series speakers are carefully designed and tested at their London facility by a team of engineers fueled by their passion for incredible sound. The S90 uses an 8" forward-firing woofer and dual rear ports to create full-bodied, dynamic bass for all your favorite music, movies, and video games. The rigid cabinet comes with spiked feet to help keep the bass tight and well-controlled. It means you'll hear clean, detailed lows, even when you crank up the volume.


  • 70-watt RMS amplifier
  • 8" front-firing woofer
  • frequency response 35-180 Hz
  • bass reflex (ported) design
  • continuously variable 40-180 Hz crossover
  • two-position phase switch
  • auto on/off mode
  • line-level/subwoofer input
  • 11-13/16"W x 11-7/8"H (12-5/8 with spiked feet attached) x 13-15/16"D
  • weight: 23.6 lbs.
  • warranty: 5 years speaker, 3 years amplifier
  • Our 60-day money-back guarantee

Hands-on research from the Crutchfield Labs (what are the Labs?)

Features and Specs
Enclosure Bass Reflex
Video Shielded Partial
Woofer Size (inches) 8
Woofer Composition Paper
Firing Direction Front
Wireless No
Preamp-Level Inputs Yes
Speaker-Level Inputs No
Speaker-Level Outputs No
Low-Pass Crossover Freq 40-180Hz
High-Pass Crossover Freq N/A
Phase Switch Yes
Amplifier Output (watts) 70
Frequency Response 35-180 Hz
Height (inches) 11-7/8
Width (inches) 11-13/16
Depth (inches) 13-15/16
Weight 23.6 lbs
Speaker Parts Warranty 5 Years
Speaker Labor Warranty 5 Years
Amplifier Parts Warranty 3 Years
Amplifier Labor Warranty 3 Years
Product Research
What's in the box?

  • Powered subwoofer
  • 59" AC power cord
  • 4 Spiked feet (with hex-nut attached)
  • Installation Guide
  • Important Safety Instructions

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.



70W Amplifier: The Cambridge Audio S90 powered subwoofer is equipped with a 70 watt (RMS) amplifier for dynamic bass response.

8" Woofer: The Cambridge Audio S90 powered subwoofer features an 8" long-throw driver with a lightweight non-pressed paper cone, foam surround, and a high temperature voice-coil for big bass sound.

Bass Reflex Enclosure: The Cambridge Audio S90 powered subwoofer features a bass reflex (ported) enclosure with two rear-firing flared ports for improved bass characteristics and lower distortion.

Magnetic Shielding: The S90 powered subwoofer is partially magnetic shielded and can be placed as close as 3.9375' to your television or video monitor.

Placement: The powered subwoofer can be placed almost anywhere in your room as bass sound is largely non-directional.

Spiked Feet: The Cambridge Audio S90 powered subwoofer includes 4 spiked feet for added stability on your carpeted floors. The spiked feet are adjustable, in case you have uneven floors. The spiked feet add 0.75" to the height of the powered sub.

Note: The powered subwoofer can be used with or without the 4 spiked feet, in case you have tile or hardwood floors.


Volume Control: The Cambridge Audio S90 powered subwoofer has a rear-panel rotary volume control to adjust the volume of the subwoofer relative to the other speakers in the system.

Crossover Frequency: The Cambridge Audio S90 powered subwoofer offers a continuously variable low-pass filter, adjustable from 40-180 Hz.

Phase Adjustment: The subwoofer's phase adjustment allows you to adjust the subwoofer's phase between 0° (normal) or 180° (reverse). If the bass sounds muddy or unclear, adjusting the phase control can sometimes strengthen the bass performance.

Auto On/Off: The S90's Auto On/Off feature will switch the powered subwoofer On and Off automatically by signal detection.


RCA/LFE Input: The powered subwoofer has gold plated left & right RCA line-level inputs for use with receivers having a subwoofer or stereo preamp output that do not contain their own low-pass crossover. The left channel RCA input doubles as the LFE input, if your receiver has an LFE output and a built-in low-pass crossover.

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Add accessories for the Cambridge Audio S90

A high-quality audio cable helps your subwoofer re-create the deep bass in music and movie soundtracks. No audio cable is included with this sub. See all categories & accessories

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For a more in-depth review and enhanced detailed information on the Cambridge Audio S90, please visit the Crutchfield website product page (/ISEO-rccbcspd/p_779S90GR/Cambridge-Audio-S90.html ).