RSL (Rogersound Labs) Speedwoofer 12S vs Monoprice Monolith M-215

Last updated: September 16, 2026

Short answer: the Monoprice Monolith M-215 for better sound quality, the RSL (Rogersound Labs) Speedwoofer 12S for the lower price. The Monoprice Monolith M-215 ranks #23 of 110 subwoofers at $2999.99. The RSL (Rogersound Labs) Speedwoofer 12S ranks #98 at $800, $2199.99 cheaper.

RSL (Rogersound Labs) Speedwoofer 12S vs Monoprice Monolith M-215

What the RSL (Rogersound Labs) Speedwoofer 12S offers: Independent CEA-2010 testing records 109.3 dB at 20 Hz and 113.2 dB through 40-80 Hz. The ported, rear enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room. Watch for: The 565.1H x 479.4W x 562.0D mm cabinet and 37.2 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

What the Monoprice Monolith M-215 offers: Independent CEA-2010 testing records 118.9 dB at 20 Hz and 125.9 dB through 40-80 Hz. The ported, front enclosure with 2x 15” (381mm) drivers has the headroom for demanding film bass in a large room. Watch for: The 1074.4H x 508.0W x 701.0D mm cabinet and 98.0 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Buy the RSL (Rogersound Labs) Speedwoofer 12S if the price is the priority over sound quality, or the Monoprice Monolith M-215 if sound quality is the priority over the price.

The RSL (Rogersound Labs) Speedwoofer 12S is not a sound-quality pick. It sits near the bottom of the 110 subwoofers; there are better options higher up.

Want more options? Browse the full Subwoofers rankings.

Buy the Monoprice Monolith M-215 at Monoprice ($2999.99) →

Specifications Side By Side

RSL (Rogersound Labs) Speedwoofer 12S Monoprice Monolith M-215
Price$800$2999.99
Ranked#98 of 110 in Large Home Subwoofers (Over 75 lbs)#23 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosureported, rearported, front
Output SPL at 15 Hz104.4 dB113.1 dB
Output SPL at 20 Hz109.3 dB118.9 dB
Output SPL at 25 Hz110.9 dB122.6 dB
Output SPL at 31.5 Hz112.5 dB125.2 dB
Output SPL at 40 Hz113.4 dB126.4 dB
Output SPL at 50 Hz113.4 dB126.1 dB
Output SPL at 63 Hz113.0 dB125.6 dB
Output SPL at 80 Hz113.1 dB125.6 dB
Output SPL at 100 Hz112.2 dB125.7 dB
CEA-2010-A Average (40-80Hz)113.2 dB125.9 dB
Dimensions22.2"H x 18.9"W x 22.1"D (565.1 x 479.4 x 562.0 mm)42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm)
Weight82 lbs (37.2 kg)216.1 lbs (98.0 kg)
Warranty?5
Cabinet Colorblack, whiteblack
CountryUnited StatesUnited States
Measurement SourceErinsAudioCornerBrent Butterworth
Drivers12" (305mm) driver2x 15" (381mm) drivers
Output SPL at 12.5 Hz-103.9 dB
Output SPL at 125 Hz-126.3 dB
Buy the Monoprice Monolith M-215 at Monoprice ($2999.99) →

How Monoprice Monolith M-215 compares with other leading options:

Prices on this page were last checked September 16, 2026 at 12:41 AM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.

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The Two Speakers In Full

RSL (Rogersound Labs) Speedwoofer 12S: $800 eBay

RSL (Rogersound Labs) Speedwoofer 12S ranking card

Pros: Independent CEA-2010 testing records 109.3 dB at 20 Hz and 113.2 dB through 40-80 Hz. The ported, rear enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room.

Cons: The 565.1H x 479.4W x 562.0D mm cabinet and 37.2 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Full RSL (Rogersound Labs) Speedwoofer 12S review and specifications →

CEA-2010-A Average (40-80Hz)113.2 dB
Cabinet Colorblack, white
CountryUnited States
Dimensions22.2"H x 18.9"W x 22.1"D (565.1 x 479.4 x 562.0 mm)
Drivers12" (305mm) driver
Enclosureported, rear
Measurement SourceErinsAudioCorner
Output SPL at 15 Hz104.4 dB
Output SPL at 20 Hz109.3 dB
Output SPL at 25 Hz110.9 dB
Output SPL at 31.5 Hz112.5 dB
Output SPL at 40 Hz113.4 dB
Output SPL at 50 Hz113.4 dB
Output SPL at 63 Hz113.0 dB
Output SPL at 80 Hz113.1 dB
Output SPL at 100 Hz112.2 dB
Warranty?
Weight82 lbs (37.2 kg)
Search eBay for RSL (Rogersound Labs) Speedwoofer 12S →

Monoprice Monolith M-215: $2999.99 Monoprice eBay

Monoprice Monolith M-215 ranking card

Pros: Independent CEA-2010 testing records 118.9 dB at 20 Hz and 125.9 dB through 40-80 Hz. The ported, front enclosure with 2x 15” (381mm) drivers has the headroom for demanding film bass in a large room.

Cons: The 1074.4H x 508.0W x 701.0D mm cabinet and 98.0 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Notes: Product # 38543

Full Monoprice Monolith M-215 review and specifications →

CEA-2010-A Average (40-80Hz)125.9 dB
Cabinet Colorblack
CountryUnited States
Dimensions42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm)
Drivers2x 15" (381mm) drivers
Enclosureported, front
Measurement SourceBrent Butterworth
Output SPL at 12.5 Hz103.9 dB
Output SPL at 15 Hz113.1 dB
Output SPL at 20 Hz118.9 dB
Output SPL at 25 Hz122.6 dB
Output SPL at 31.5 Hz125.2 dB
Output SPL at 40 Hz126.4 dB
Output SPL at 50 Hz126.1 dB
Output SPL at 63 Hz125.6 dB
Output SPL at 80 Hz125.6 dB
Output SPL at 100 Hz125.7 dB
Output SPL at 125 Hz126.3 dB
Warranty5
Weight216.1 lbs (98.0 kg)
Check current price at Monoprice ($2999.99) →Search eBay for Monoprice Monolith M-215 →