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 #63 (rated 4.2/5) for the Monoprice Monolith 13 THX Ultra. If you want one new, the JTR Speakers Orbit Shifter PRO ranks #1 at $4,499.
The case for 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. 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.
What the Monoprice Monolith 13 THX Ultra does well: A THX Ultra certified 13 inch ported subwoofer with deep, strong bass for large rooms at a good price used. Watch for: The 604.5H x 515.6W x 739.1D mm cabinet and 153.2 lbs (69.5 kg) mass make this a serious placement and moving commitment.
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 THX Ultra certified 13 inch ported subwoofer with deep, strong bass for large rooms at a good price used.
Prices on this page were last checked October 31, 2026 at 7:11 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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| JTR Speakers Captivator S2 | Monoprice Monolith 13 THX Ultra | |
|---|---|---|
| Price | $3,995 Discontinued | $1,700 Discontinued |
| Ranked | #9 of 143 in Large Home Subwoofers (Over 75 lbs) | #63 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 | 94.0 dB |
| Output SPL at 15 Hz | 108.7 dB | 109.1 dB |
| Output SPL at 20 Hz | 115.1 dB | 115.0 dB |
| Output SPL at 25 Hz | 119.7 dB | 118.0 dB |
| Output SPL at 31.5 Hz | 124.8 dB | 119.5 dB |
| Output SPL at 40 Hz | 129.3 dB | 120.3 dB |
| Output SPL at 50 Hz | 130.3 dB | 120.7 dB |
| Output SPL at 63 Hz | 129.4 dB | 121.4 dB |
| Output SPL at 80 Hz | 128.5 dB | 122.1 dB |
| Output SPL at 100 Hz | 128.1 dB | 122.7 dB |
| Output SPL at 125 Hz | 128.0 dB | 123.8 dB |
| CEA-2010-A Average (40-80Hz) | 129.4 dB | 121.1 dB |
| Dimensions | 40”H x 21”W x 18”D (1016.0 x 533.4 x 457.2 mm) | 23.8”H x 20.3”W x 29.1”D (604.5 x 515.6 x 739.1 mm) |
| Weight | 220 lbs (99.8 kg) | 153.2 lbs (69.5 kg) |
| Warranty | 5/3 | 5 |
| Country | United States | United States |
| Measurement Source | Data-bass | Audioholics |
| Drivers | 2x 18” (457mm) drivers | 13” (330mm) driver |
| Inputs | XLR (balanced), RCA | XLR (stereo balanced), RCA (stereo/mono) |
| 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 |
Related Speaker Comparisons
How JTR Speakers Captivator S2 compares with other leading options:
- JTR Speakers Captivator S2 vs JTR Speakers Orbit Shifter PRO
- JTR Speakers Captivator S2 vs JTR Speakers Orbit Shifter LFU
- JTR Speakers Captivator S2 vs WW Speaker Cabinets X21 - B&C 21DS115-4
- JTR Speakers Captivator S2 vs Pro Audio Technology LFC-24sm
- JTR Speakers Captivator S2 vs Power Sound Audio (PSA) TRIAX