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 #141 (rated 3.3/5) for the BK Electronics Monolith-DF. If you want one new, the JTR Speakers Orbit Shifter PRO ranks #1 at $4,499.
The JTR Speakers Captivator S2 is the better-sounding option. A tall sealed subwoofer with two 18 inch drivers and serious deep bass output for demanding movies in a large room. The catch: The 1016.0H x 533.4W x 457.2D mm cabinet and 220 lbs (99.8 kg) mass make this a serious placement and moving commitment.
Why pick the BK Electronics Monolith-DF: A down ported 12 inch subwoofer with balanced XLR and RCA inputs at a low price, now discontinued. The catch: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority.
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.
Still deciding? The full Subwoofers rankings cover every ranked option.
A tall sealed subwoofer with two 18 inch drivers and serious deep bass output for demanding movies in a large room.
A down ported 12 inch subwoofer with balanced XLR and RCA inputs at a low price, now discontinued.
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Specifications Side By Side
| JTR Speakers Captivator S2 | BK Electronics Monolith-DF | |
|---|---|---|
| Price | $3,995 Discontinued | £406.95 Discontinued |
| Ranked | #9 of 143 in Large Home Subwoofers (Over 75 lbs) | #141 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, bottom |
| 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 | 91.3 dB |
| Output SPL at 20 Hz | 115.1 dB | 102.0 dB |
| Output SPL at 25 Hz | 119.7 dB | 106.4 dB |
| Output SPL at 31.5 Hz | 124.8 dB | 108.3 dB |
| Output SPL at 40 Hz | 129.3 dB | 108.6 dB |
| Output SPL at 50 Hz | 130.3 dB | 108.7 dB |
| Output SPL at 63 Hz | 129.4 dB | 108.6 dB |
| Output SPL at 80 Hz | 128.5 dB | 107.7 dB |
| Output SPL at 100 Hz | 128.1 dB | - |
| Output SPL at 125 Hz | 128.0 dB | - |
| CEA-2010-A Average (40-80Hz) | 129.4 dB | 108.4 dB |
| Dimensions | 40”H x 21”W x 18”D (1016.0 x 533.4 x 457.2 mm) | 23.8”H x 21.3”W x 16.5”D (603.8 x 539.8 x 419.9 mm) |
| Weight | 220 lbs (99.8 kg) | 103.2 lbs (46.8 kg) |
| Warranty | 5/3 | 2 |
| Country | United States | United Kingdom |
| Measurement Source | Data-bass | Ilkka Rissanen |
| Drivers | 2x 18” (457mm) drivers | 12” (305mm) driver with ported design |
| Inputs | XLR (balanced), RCA | XLR (balanced), RCA (unbalanced) |
| XLR Input | Yes | Yes |
| RCA Input | Yes | Yes |
| TRS Input | No | No |
| Optical Input | No | No |
| Coaxial Input | No | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | No | No |
| Aux Input | No | No |
| Cabinet Color | - | black, wood |
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