Short answer: the Monoprice Monolith M-215 if sound quality matters most, the Monoprice Monolith M15-S if price matters most. The Monoprice Monolith M-215 ranks #23 of 110 subwoofers, rated 4.4/5, at $2999.99. The Monoprice Monolith M15-S ranks #72, rated 4.1/5, at $999, $2000.99 cheaper.
Buy the Monoprice Monolith M-215 if sound quality matters more than the price. Buy the Monoprice Monolith M15-S if the price matters more than sound quality.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith M-215 | Monoprice Monolith M15-S | |
|---|---|---|
| Price | $2999.99 | $999 |
| Ranked | #23 of 110 in Large Home Subwoofers (Over 75 lbs) | #72 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | sealed |
| Output SPL at 12.5 Hz | 103.9 dB | - |
| Output SPL at 15 Hz | 113.1 dB | 100.1 dB |
| Output SPL at 20 Hz | 118.9 dB | 105.6 dB |
| Output SPL at 25 Hz | 122.6 dB | 111.2 dB |
| Output SPL at 31.5 Hz | 125.2 dB | 115.2 dB |
| Output SPL at 40 Hz | 126.4 dB | 118.4 dB |
| Output SPL at 50 Hz | 126.1 dB | 119.3 dB |
| Output SPL at 63 Hz | 125.6 dB | 119.6 dB |
| Output SPL at 80 Hz | 125.6 dB | 118.9 dB |
| Output SPL at 100 Hz | 125.7 dB | 119.1 dB |
| Output SPL at 125 Hz | 126.3 dB | 118.9 dB |
| CEA-2010-A Average (40-80Hz) | 125.9 dB | 119.0 dB |
| Dimensions | 42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm) | 23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm) |
| Weight | 216.1 lbs (98.0 kg) | 80 lbs (36.3 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | - |
| Country | United States | United States |
| Measurement Source | Brent Butterworth | Manufacturer |
| Drivers | 2x 15" (381mm) drivers | 15" (381mm) driver |
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Prices on this page were last checked September 23, 2026 at 11:24 PM 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
Monoprice Monolith M-215: $2999.99 Monoprice eBay
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 Color | black |
| Country | United States |
| Dimensions | 42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm) |
| Drivers | 2x 15" (381mm) drivers |
| Enclosure | ported, front |
| Measurement Source | Brent Butterworth |
| Output SPL at 12.5 Hz | 103.9 dB |
| Output SPL at 15 Hz | 113.1 dB |
| Output SPL at 20 Hz | 118.9 dB |
| Output SPL at 25 Hz | 122.6 dB |
| Output SPL at 31.5 Hz | 125.2 dB |
| Output SPL at 40 Hz | 126.4 dB |
| Output SPL at 50 Hz | 126.1 dB |
| Output SPL at 63 Hz | 125.6 dB |
| Output SPL at 80 Hz | 125.6 dB |
| Output SPL at 100 Hz | 125.7 dB |
| Output SPL at 125 Hz | 126.3 dB |
| Warranty | 5 |
| Weight | 216.1 lbs (98.0 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Brent Butterworth; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
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Monoprice Monolith M15-S: $999 eBay
Pros: Published CEA-2010 specifications list 105.6 dB at 20 Hz and 119.0 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver has the headroom for demanding film bass in a large room.
Cons: The 596.9H x 424.2W x 500.4D mm cabinet and 36.3 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Notes: Product # 35141
Full Monoprice Monolith M15-S review and specifications →
| CEA-2010-A Average (40-80Hz) | 119.0 dB |
|---|---|
| Country | United States |
| Dimensions | 23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm) |
| Drivers | 15" (381mm) driver |
| Enclosure | sealed |
| Measurement Source | Manufacturer |
| Output SPL at 15 Hz | 100.1 dB |
| Output SPL at 20 Hz | 105.6 dB |
| Output SPL at 25 Hz | 111.2 dB |
| Output SPL at 31.5 Hz | 115.2 dB |
| Output SPL at 40 Hz | 118.4 dB |
| Output SPL at 50 Hz | 119.3 dB |
| Output SPL at 63 Hz | 119.6 dB |
| Output SPL at 80 Hz | 118.9 dB |
| Output SPL at 100 Hz | 119.1 dB |
| Output SPL at 125 Hz | 118.9 dB |
| Warranty | 5 |
| Weight | 80 lbs (36.3 kg) |
- Reviews, Comparisons and Sound Samples
- These figures are manufacturer-specified rather than independently measured.
- Head-to-Head Comparisons
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- Monoprice Monolith M15-S vs Rythmik FV15HP
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- Monoprice Monolith M15-S vs Monoprice Monolith 16 THX Ultra
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