Short answer: the WW Speaker Cabinets X21 - B&C 21DS115-4. It ranks #3 of 143 subwoofers by sound quality (rated 4.6/5) at $3,995 and is still sold new; the JTR Speakers Captivator S2 ranks #9 (rated 4.5/5) and is discontinued, so it is only an option used.
Why pick the JTR Speakers Captivator S2: A tall sealed subwoofer with two 18 inch drivers and serious deep bass output for demanding movies in a large room. Watch for: 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 WW Speaker Cabinets X21 - B&C 21DS115-4: A passive 21 inch ported subwoofer with enormous output, made for big home theater rooms. Watch for: Premium $3995 price, massive 114.6 lbs (52 kg) cabinet, and ported room gain dependency.
Buy the WW Speaker Cabinets X21 - B&C 21DS115-4. It is rated higher for sound quality, and the JTR Speakers Captivator S2 is discontinued, so it is only available used.
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 passive 21 inch ported subwoofer with enormous output, made for big home theater rooms.
Prices on this page were last checked October 29, 2026 at 4:42 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 S2 | WW Speaker Cabinets X21 - B&C 21DS115-4 | |
|---|---|---|
| Price | $3,995 Discontinued | $3,995 Passive |
| Ranked | #9 of 143 in Large Home Subwoofers (Over 75 lbs) | #3 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, front |
| Output SPL at 10 Hz | 100.3 dB | - |
| Output SPL at 12.5 Hz | 103.3 dB | 96.2 dB |
| Output SPL at 15 Hz | 108.7 dB | 111.9 dB |
| Output SPL at 20 Hz | 115.1 dB | 121.9 dB |
| Output SPL at 25 Hz | 119.7 dB | 120.8 dB |
| Output SPL at 31.5 Hz | 124.8 dB | 122.5 dB |
| Output SPL at 40 Hz | 129.3 dB | 126.7 dB |
| Output SPL at 50 Hz | 130.3 dB | 129.2 dB |
| Output SPL at 63 Hz | 129.4 dB | 132.9 dB |
| Output SPL at 80 Hz | 128.5 dB | 136.3 dB |
| Output SPL at 100 Hz | 128.1 dB | 139.0 dB |
| Output SPL at 125 Hz | 128.0 dB | 140.1 dB |
| CEA-2010-A Average (40-80Hz) | 129.4 dB | 131.3 dB |
| Dimensions | 40”H x 21”W x 18”D (1016.0 x 533.4 x 457.2 mm) | 24”H x 32”W x 32”D (609.6 x 812.8 x 812.8 mm) |
| Weight | 220 lbs (99.8 kg) | 115.1 lbs (52.2 kg) |
| Warranty | 5/3 | - |
| Country | United States | United States |
| Measurement Source | Data-bass | Data-bass |
| Drivers | 2x 18” (457mm) drivers | 21” (533mm) 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 | - |
| Passive | - | Yes |
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