Short answer: the JTR Speakers Captivator 4000ULF for better sound quality, the Monoprice Monolith M-215 for the lower price. The JTR Speakers Captivator 4000ULF ranks #6 of 143 subwoofers, rated 4.5/5, at $5,699. The Monoprice Monolith M-215 ranks #24, rated 4.4/5, at $1,499.99, $4,199.01 cheaper.
Buy the JTR Speakers Captivator 4000ULF if sound quality is the priority over the price, or the Monoprice Monolith M-215 if the price is the priority over sound quality.
Want more options? Browse the full Subwoofers rankings.
Prices on this page were last checked November 7, 2026 at 7:34 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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Specifications Side By Side
| JTR Speakers Captivator 4000ULF | Monoprice Monolith M-215 | |
|---|---|---|
| Price | $5,699 each | $1,499.99 |
| Ranked | #6 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 10 Hz | 111.0 dB | - |
| Output SPL at 12.5 Hz | 115.3 dB | 103.9 dB |
| Output SPL at 15 Hz | 119.3 dB | 113.1 dB |
| Output SPL at 20 Hz | 122.3 dB | 118.9 dB |
| Output SPL at 25 Hz | 126.1 dB | 122.6 dB |
| Output SPL at 31.5 Hz | 129.3 dB | 125.2 dB |
| Output SPL at 40 Hz | 130.7 dB | 126.4 dB |
| Output SPL at 50 Hz | 131.2 dB | 126.1 dB |
| Output SPL at 63 Hz | 130.9 dB | 125.6 dB |
| Output SPL at 80 Hz | 130.6 dB | 125.6 dB |
| Output SPL at 100 Hz | 130.5 dB | 125.7 dB |
| Output SPL at 125 Hz | 129.5 dB | 126.3 dB |
| CEA-2010-A Average (40-80Hz) | 130.8 dB | 125.9 dB |
| Dimensions | 41”H x 20.5”W x 39.5”D (1041.4 x 520.7 x 1003.3 mm) | 42.3”H x 20”W x 27.6”D (1074.4 x 508.0 x 701.0 mm) |
| Weight | 265 lbs (120.2 kg) | 216.1 lbs (98.0 kg) |
| Warranty | 5/3 | 5 |
| Cabinet Color | black, custom | black |
| Country | United States | United States |
| Measurement Source | Data-bass | Brent Butterworth |
| Drivers | 2x 18” (457mm) driver | 2x 15” (381mm) drivers |
| Inputs | XLR, RCA | - |
| XLR Input | Yes | - |
| RCA Input | Yes | - |
| TRS Input | No | - |
| Optical Input | No | - |
| Coaxial Input | No | - |
| USB Input | No | - |
| HDMI Input | No | - |
| AES Input | No | - |
| Aux Input | No | - |
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