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    SKU: OSD-IWS-88

    OSD IWS88Dual 8" In Wall Subwoofer 350W, Injected Woofers Back Bridge Plate

    Purchase In Wall Subwoofer OSD IWS88 Dual 8" Injected Woofers Back Bridge Plate
    • Outdoor Speaker Depot SKU: OSD-IWS-88 dual-in-wall-passive-subwoofer-8-inch
    • In Stock


      Compare at: $161.99
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    We improved the lower end of our popular dual in-wall subwoofer. By adding a strong reinforced back plate to stiff the structure of the subwoofer, we make it to sound deeper and clean. A subwoofer is designed to reproduce the lowest of audible frequencies and will give you that spine-tingling rumble effect that takes you out of reality and into the plot. With dual 8" Injected polypropylene woofers, bigger magnets and 350 Watts of power handling, the IWS-88 in-wall subwoofer performs excellently for home theater surround sound applications as well as for listening to music. Like all OSD Audio speakers, the IWS-88 includes a dog-ear bracket system that mounts securely to the sheet-rock after the cut-out hole has been made and the speaker has been dropped into the hole. The grille is paintable to match your room decor and we even include a cutout template that doubles as a paint shield. You'll experience thunderous, room-filling bass without filling up floor space.

    Amplifier Suggestions
    Because this is a passive speaker, it will require a subwoofer amplifier to power it. An ideal match to this subwoofer is our OSD SMP500 dedicated subwoofer amplifier that features 400W RMS @ 4 ohms, Variable High Cut Filter 30Hz-150Hz; front panel Knob, and Choice of Signal Level Input or LFE (Low-Frequency Effects).

    Warning: California's Proposition 65


    This product can expose you to chemicals, including vinyl chloride, which is known to the State of California to cause cancer. For more information, go to

    • Speaker Type: Dual 8" In-Wall Subwoofer
    • Woofer: Dual 8" Injected Polypropylene w/ Reinforced Back Plate
    • Frequency Response: 38Hz-500Hz
    • Power Handling: 350 Watts
    • Sensitivity: 90 dB @ 1W/1M
    • Impedance: 4 Ohms
    • Inputs: Spring Binding Posts
    • Install-friendly Dog Ear Installation Brackets
    • Cut-Out Template for Easy Installation
    • Paintable Grille Included
    • Sold As: Single
    • Mounting Depth (Assuming .5" Drywall): 3.56"
    • Unit Dimensions: (L x H x D) 11.43" x 18.43" x 4"
    • Cutout Dimensions: (L x H) 10.25" x 17.75"
    • Weight: 11 lbs
    • Warranty: 10 Years
    • *Note: Requires Additional Subwoofer Amplifier
    31 Questions asked
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    What's on your mind?

    Ricky • 12/17/2019, 2:17:43 PM Two questions: 1. Do you recommend placing foam or dampning material behind the sub inside the wall? Or just keep the wall cavity as is? 2. For two subs, what amplifier do you recommend? What's required? Thank you, Ricky
    Customer Service • 12/17/2019, 2:17:43 PM
    Hi Ricky: The dampening material can be used to tune the sub in your wall. I would experiment without filling, then with filling to see which you like the best. Typically fiberfill is added to make the Subwoofer think it is a larger cavity. The SMP500 would be the best for the Subwoofer especially if you want to power two subs. You would need to run them in series so the amp would see an 8-ohm load versus two in parallel since that would drop the two four ohm speakers down to a 2-ohm load which it would not like. The biggest bang for the buck would be purchasing 4 of the Subs and wiring in Series-parallel, so the amp sees a 4-ohm load. It drives up the sensitivity (making the subs much more efficient), and now you have the cone material of eight 8" subs. Then you are getting the most out of the SMP500. TL/5320
    Andrew • 12/17/2019, 2:17:43 PM I ordered two of these can I adjust the internal wiring so I can have a series/parallel so I end up with a 4 ohm load?
    Customer Service • 12/17/2019, 2:17:43 PM
    Hello Andrew:The IWS88 is a 4-ohm subwoofer already meaning it has 2 8 ohm drivers wired in parallel. When wiring two together you would get a 2-ohm load in parallel and 8-ohm in series. If you series-parallel the four 8-ohm drivers, you will still get 8-ohm. Now if you bought four IWS88, to begin with, and series-parallel them together, you would get your 4-ohm load, and our SMP500 would be the perfect amp to drive them. Did you buy them directly from us; we could offer you a bundle discount for purchasing the two additional IWS88 (and the amp as well)? The four speakers in series-parallel would dramatically raise the power handling and sensitivity while cutting down on distortion. Please let me know if you are interested; tim@osdaudio.comTL/5614
    Andrew • 12/17/2019, 2:17:43 PM I ordered two of these can I adjust the internal wiring so I can have a series/parallel so I end up with a 4 ohm load?
    Customer Service • 12/17/2019, 2:17:43 PM
    Thanks. Shortly after I hit send I did the math and realized there is no way to get there from here. :) These 2 subs and the SMP300 are arriving in a few days. Will the impedance matching volume control help to get the most out of the amp? I don't think i am ready for quite that many backboxes and holes in my ceiling.
    Stephen • 12/17/2019, 2:17:43 PM Will I need an amp in addition to my Denon AVR receiver with the sub port?
    Customer Service • 12/17/2019, 2:17:43 PM
    Hi Stephan:Yes, you will need a dedicated subwoofer amplifier simial to our SMP300 or SMP500 DSP Digital Amplifier. Both can do a 4-ohm load like that featured on the IWS88.TL/5635
    Vince • 12/03/2020, 9:36:44 AM In your response to Nim on 12/17/2019, 2:17:43 PM, you recommend building an enclosure. Is that 1/4 inch board (assuming plywood) on the front face? Meaning the wall to which the subwoofer is attached or is on the opposite drywall that acts as the rear of the enclosure? Ours is a retrofit so we would have to get the board inside the cut out. If the board is to brace the front side then perhaps glued on board strips along the perimeter of the cut out will work? BTW: Thank you for the excellent support you provide below. This was the reason why we shopped Outdoor Speaker Depot.
    Customer Service • 12/04/2020, 1:11:37 AM
    Hi Vince: The 1/4" board was most definitely for the back of the box hopefully preventing more signal escaping out the back sheetrock. It is different when doing retrofit versus new construction. Fiber fill can be more important for retrofit allowing you to tune the enclosure. The more fiber fill you add the more the speaker thinks it is working in a larger enclosure. The fiber fill really absorbs the low frequencies. I wouldn't worry about reinforcing the front. The eight dog ears will provide a tight seal. Don't forget adding a bead of Silicone on the back of the front bezel/frame. You could apply the Silicone around the cutout hole instead. Thank you for the kind words. TL/12/3/20