Short answer: the Monoprice Monolith M-215 for better sound quality, the XTZ Sound SUB 3X12 for the lower price. The Monoprice Monolith M-215 ranks #18 of 97 subwoofers at $2500. The XTZ Sound SUB 3X12 ranks #19 at $1412.84, $1087.16 cheaper.
What the XTZ Sound SUB 3X12 offers: Independent CEA-2010 testing records 114.5 dB at 20 Hz and 125.3 dB through 40-80 Hz. The ported, front enclosure with 3x 12” (305mm) drivers has the headroom for demanding film bass in a large room. Watch for: The 1158.2H x 535.9W x 556.3D mm cabinet and 77.4 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 XTZ Sound SUB 3X12 if the price is the priority over sound quality, or the Monoprice Monolith M-215 if sound quality is the priority over the price.
Specifications Side By Side
| XTZ Sound SUB 3X12 | Monoprice Monolith M-215 | |
|---|---|---|
| Price | $1,412.84 | $2,500 |
| Ranked | #19 of 97 in Large Powered Home Subwoofers (Over 75 lbs) | #18 of 97 in Large Powered Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 12.5 Hz | 100.0 dB | 103.9 dB |
| Output SPL at 15 Hz | 109.1 dB | 113.1 dB |
| Output SPL at 20 Hz | 114.5 dB | 118.9 dB |
| Output SPL at 25 Hz | 118.5 dB | 122.6 dB |
| Output SPL at 31.5 Hz | 121.8 dB | 125.2 dB |
| Output SPL at 40 Hz | 124.8 dB | 126.4 dB |
| Output SPL at 50 Hz | 125.4 dB | 126.1 dB |
| Output SPL at 63 Hz | 125.4 dB | 125.6 dB |
| Output SPL at 80 Hz | 125.6 dB | 125.6 dB |
| Output SPL at 100 Hz | 126.1 dB | 125.7 dB |
| Output SPL at 125 Hz | 126.4 dB | 126.3 dB |
| CEA-2010-A Average (40-80Hz) | 125.3 dB | 125.9 dB |
| Dimensions | 45.6"H x 21.1"W x 21.9"D (1158.2 x 535.9 x 556.3 mm) | 42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm) |
| Weight | 170.6 lbs / 77.4 kg | 216.1 lbs / 98.0 kg |
| Warranty | 5/2 | 5 |
| Cabinet Color | black | black |
| Country | Sweden | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 3x 12" (305mm) drivers | 2x 15" (381mm) drivers |
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Prices on this page were last checked September 8, 2026 at 6:02 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
XTZ Sound SUB 3X12: $1,412.84 eBay
Pros: Independent CEA-2010 testing records 114.5 dB at 20 Hz and 125.3 dB through 40-80 Hz. The ported, front enclosure with 3x 12” (305mm) drivers has the headroom for demanding film bass in a large room.
Cons: The 1158.2H x 535.9W x 556.3D mm cabinet and 77.4 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 XTZ Sound SUB 3X12 review and specifications →
| CEA-2010-A Average (40-80Hz) | 125.3 dB |
|---|---|
| Cabinet Color | black |
| Country | Sweden |
| Dimensions | 45.6"H x 21.1"W x 21.9"D (1158.2 x 535.9 x 556.3 mm) |
| Drivers | 3x 12" (305mm) drivers |
| Enclosure | ported, front |
| Measurement Source | Audioholics |
| Output SPL at 12.5 Hz | 100.0 dB |
| Output SPL at 15 Hz | 109.1 dB |
| Output SPL at 20 Hz | 114.5 dB |
| Output SPL at 25 Hz | 118.5 dB |
| Output SPL at 31.5 Hz | 121.8 dB |
| Output SPL at 40 Hz | 124.8 dB |
| Output SPL at 50 Hz | 125.4 dB |
| Output SPL at 63 Hz | 125.4 dB |
| Output SPL at 80 Hz | 125.6 dB |
| Output SPL at 100 Hz | 126.1 dB |
| Output SPL at 125 Hz | 126.4 dB |
| Warranty | 5/2 |
| Weight | 170.6 lbs / 77.4 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Monoprice Monolith M-215: $2,500 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
- Head-to-Head Comparisons
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