Short answer: both are discontinued, so this only matters if you are buying used. Used, the JTR Speakers Captivator S2 is the better pick: it ranks #9 of 143 subwoofers by sound quality (rated 4.5/5), against #88 (rated 4.1/5) for the Monoprice Monolith M15-S. If you want one new, the JTR Speakers Orbit Shifter PRO ranks #1 at $4,499.
Buy the JTR Speakers Captivator S2 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, start with the JTR Speakers Orbit Shifter PRO instead.
Want more options? Browse the full Subwoofers rankings.
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Specifications Side By Side
| JTR Speakers Captivator S2 | Monoprice Monolith M15-S | |
|---|---|---|
| Price | $3,995 Discontinued | $999 Discontinued |
| Ranked | #9 of 143 in Large Home Subwoofers (Over 75 lbs) | #88 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | sealed |
| Output SPL at 10 Hz | 100.3 dB | - |
| Output SPL at 12.5 Hz | 103.3 dB | - |
| Output SPL at 15 Hz | 108.7 dB | 100.1 dB |
| Output SPL at 20 Hz | 115.1 dB | 105.6 dB |
| Output SPL at 25 Hz | 119.7 dB | 111.2 dB |
| Output SPL at 31.5 Hz | 124.8 dB | 115.2 dB |
| Output SPL at 40 Hz | 129.3 dB | 118.4 dB |
| Output SPL at 50 Hz | 130.3 dB | 119.3 dB |
| Output SPL at 63 Hz | 129.4 dB | 119.6 dB |
| Output SPL at 80 Hz | 128.5 dB | 118.9 dB |
| Output SPL at 100 Hz | 128.1 dB | 119.1 dB |
| Output SPL at 125 Hz | 128.0 dB | 118.9 dB |
| CEA-2010-A Average (40-80Hz) | 129.4 dB | 119.0 dB |
| Dimensions | 40”H x 21”W x 18”D (1016.0 x 533.4 x 457.2 mm) | 23.5”H x 16.7”W x 19.7”D (596.9 x 424.2 x 500.4 mm) |
| Weight | 220 lbs (99.8 kg) | 80 lbs (36.3 kg) |
| Warranty | 5/3 | 5 |
| Country | United States | United States |
| Measurement Source | Data-bass | Manufacturer |
| Drivers | 2x 18” (457mm) drivers | 15” (381mm) driver |
| Inputs | XLR (balanced), 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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