This product is a vintage Polk model and is not available for sale, but it may still be available in some stores as a closeout or used product. The following text is taken from the original sales brochure for this product and does not reflect current availability. If you happen to have any question or concerns about this product, or any other Polk Audio product, feel free to contact our Customer Service Department at 1-800-377-7655 Monday - Friday, 9am - 5:30pm EST


Dual-Driver Powered Subwoofer

Available Finishes:

Loudspeakers For
Serious Listeners

Bass Too Big For Polk Audio

When we got the DVD of "Underworld," the first thing we all did was rush into the demo room, where our newest loudspeaker models are lined up around a flat-screen television. From the get-go, the "Underworld" DVD is an aural orgasm of hectic, full-range mayhem from all channels and profound, positively subterranean low frequency effects -- which we were ready to experience via the brand new LSiW in the corner. Nothing prepared us for the bass on this DVD. After a while, as we were nodding in appreciation and smiling at each other as the movie unfolded around us, with bullets flying and music pounding, thinking about how great our big speakers sounded, we realized that all of our bodily functions had ceased. Amazingly, we were all dead!

The only things keeping us alive were the immense, physical, throbbing, waves of low frequencies that were flowing out of the LSiW and hammering our hearts and lungs in and out! We were dead guys, watching "Underworld," being kept alive by the pure bass power of the LSiW!

And then Peter (big time VP; very important) came in to the demo room from some far-flung meeting all the way in another part of the building and asked us TURN IT DOWN because it was disturbing their meeting. We work at Polk Audio -- and WE HAD TO TURN IT DOWN. That's BIG BASS.

The moral of that fun little story is not that we don't have enough to do here at Polk Audio, nor that we usually enjoy silly vampire movies. It's that the LSiW is Polk Audio's most advanced Powered Subwoofer. It is specifically engineered to deliver gobs of bass with the accuracy, depth and power needed for ultra-performance audio systems such as the Polk Audio LSi Series. Multiple input/output options and extreme user controls allow more flexibility, while two bass venting technologies -- Polk's Power Port combined with Slot Load Venting -- pump out waves of thunderous, musical bass.

LSiW Features:

  • Dual 10 inch (25cm) Dynamic Balance Drivers have nearly 40% more surface area than a single 12-inch driver and a much greater force to mass ratio. The result is lower distortion and higher Sound Pressure Level with superb detail and musicality for truly big, tight, emotionally satisfying bass.
  • High roll surrounds allow longer cone excursion for louder, gut-kicking bass.
  • Both drivers feature vented, four-layer, long-winding-height Voice Coils, Vented Pole Pieces, and Aluminum Formers, ensuring better heat dissipation and less heat build-up for a long life of big bass.
  • Both drivers are magnetically shielded, so the LSiW is safe for placement near video equipment with no risk of video picture distortion.
  • Two Bass Venting Technologies -- Slot Load Vent and Power Port -- combine to virtually eliminate port turbulence and noise. The LSiW specializes in low distortion, high output, deep bass that you can really feel.
  • During the design process, a state-of-the-art Klippel laser optimization machine is used to perfectly position the voice coil in the magnetic gap. This ensures that equal force is placed on the driver cone in both forward and backward travel. The result is tighter, more detailed, lower distortion bass.
  • Heavy duty MDF Cabinet with 1.75-inch (4.5cm) side panels and rigid internal bracing -- a level of craftsmanship rarely seen in subs at this price level -- control vibration for near-zero cabinet resonance.
  • High gloss lacquer finish with your choice of Ebony or Cherry real wood veneer side panels.
  • Adjustable Carpet Spikes/Rubber Feet reduce bass coloration and ensure that the LSiW doesn't "walk around your room" like an old washing machine.
  • Stiff, low-resonance, driver suspension keeps the driver stable for increased transient bass response and more musical detail and definition.
  • Huge, fire-retardant flat NOMEX Spiders provide highly reliable mechanical and thermal stability for safe, extended linear motion and long excursion bass.
  • Convenient Front Panel Control Pod gives instant access to Volume Control, Low Pass Adjustment, 3dB Bass Boost Toggle Switch and power indicator light to give you more immediate subwoofer control.

    Amplifier features:

  • Hybrid Design Amplifier incorporates a High Current Linear Class B Power Supply and a Class D Switching Output Stage provides maximum power and cool operation for loud, effortless performance, low distortion and long-term reliable operation.
  • Mechanically isolated 5.75-inch-(14.6cm)-diameter solid core Torodial Transformer dishes out high voltage, high current power with less radiated noise for quieter performance. (You'll never hear any mechanical hum coming from this big baby!) It's so big that it allows this amplifier to be rated at 825 Watts Peak -- more than a whole Horsepower (which is 746 Watts, in case you need to know)!
  • Eighth-inch (3.2mm)-thick metal amplifier mounting plate dissipates heat, keeping the amp cool for long term reliability.
  • Multiple connection options, including Filtered Line Ins & Outs, Speaker Level Ins & Outs, adjustable-filtered Line In and unfiltered LFE give you unprecedented hookup flexibility and more control.
  • Electrolytic Power Supply Storage Capacitors store up to 16,400 microfarads of "backup" power for accurate, extended-peak performance with no power supply "sags."
  • Glass Epoxy Wave-Soldered Circuit Board won't bend or shrink; plated through-holes allow twice the amount of component contact area; shorter traces ensure less signal path noise.
  • High current, low impedance FETs combine with Mylar Capacitors in the Output Stage for quieter amp operation and better sound.
  • Dual low-noise Operational Amplifiers at the input gain stages give this amp an enhanced ability to change voltage "on the fly," for excellent transient response (that's tight bass to you).
  • Gold Plated Five-Way Binding Posts for the most secure connection options.
  • LSiW available in 110 and 220 Volts.

Note: The LSiW is NOT recommended as a lifesaving device and can not really keep someone alive by replicating the motion of the heart and lungs, as related in the story above. That's just a story. We weren't really dead. But the LSiW does dole out some serious big pounding physical bass you just have to feel to believe. Don't believe the living dead part. Do believe the big bass part. Okay, ma? I'm still alive and doing fine.

Driver Complement

Diameter10" (25.40cm) 
TypeDynamic Balance long-throw drivers with Polymer Composite cones 


Total Frequency Response20Hz - 160Hz 
Upper -3dB Limit125Hz kHz
Lower -3dB Limit30  Hz
Power Handling
Continuous400 watts
Peak825 watts
Subwoofer Crossover50Hz - 140 Hz 

Amplifier Specs

Power Requirements (voltage)120V or 240V AC 50/60 Hz 
Bandwidth20Hz - 145Hz 
220V AvailabilityYes 
Continuous Average Output
Amplifier TypeSubwoofer 
Dynamic Power825 watts


Cabinet Dimensions
Height16 3/4" (42.55cm) 
Width16 7/8" (42.86cm) 
Depth19 3/8" (49.21cm) 
Enclosure Type
Subwoofer Enclosure TypeVented via slot loaded Power Port 


Total Shipping Weight81.00 pounds


Speaker Warranty5 years parts and labor (original purchaser) 
Subwoofer Amplifier Warranty3 years parts and labor (original purchaser) 

Specifications, dimensions and features subject to change without notice. For more information call us at 1-800-377-7655 (USA and Canada). Outside of North America call +1 (410) 358-3600.

LSiW Media

LSiW Literature

Want to know more? Want to dig just a little deeper to learn about this product? Here's a list of source material that will give more detail, other perspectives, and answer questions you may have.

LSiW Accessories