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 #24 of 143 subwoofers, rated 4.4/5, at $2,999.99. The XTZ Sound SUB 3X12 ranks #28, rated 4.3/5, at $1,412.84, $1,587.15 cheaper.
Why pick the XTZ Sound SUB 3X12: A triple 12 inch subwoofer with huge, deep output for movies in a large room, for less than most rivals. The tradeoff: The 1158.2H x 535.9W x 556.3D mm cabinet and 170.6 lbs (77.4 kg) mass make this a serious placement and moving commitment.
What the Monoprice Monolith M-215 does well: A dual 15 inch ported subwoofer with excellent output down to the lowest notes, a strong value for large home theaters. Watch for: The 1074.4H x 508.0W x 701.0D mm cabinet and 216.1 lbs (98.0 kg) mass make this a serious placement and moving commitment.
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.
Still deciding? The full Subwoofers rankings cover every ranked option.
A triple 12 inch subwoofer with huge, deep output for movies in a large room, for less than most rivals.
A dual 15 inch ported subwoofer with excellent output down to the lowest notes, a strong value for large home theaters.
Prices on this page were last checked October 23, 2026 at 8:27 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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Specifications Side By Side
| XTZ Sound SUB 3X12 | Monoprice Monolith M-215 | |
|---|---|---|
| Price | $1,412.84 | $2999.99 |
| Ranked | #28 of 143 in Large Home Subwoofers (Over 75 lbs) | #24 of 143 in Large 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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