Short answer: the JTR Speakers Captivator RS1, if you are buying new. The Monoprice Monolith 16 THX Ultra ranks higher than it (#19 vs #56 of 143 subwoofers, 4.4/5 vs 4.2/5) but is discontinued, so only consider it used; the JTR Speakers Captivator RS1 is still sold new at $3,300.
Why pick the Monoprice Monolith 16 THX Ultra: A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used. Watch for: Heavy at 172 lbs (78 kg) and ported design can interact with room acoustics.
The case for the JTR Speakers Captivator RS1: A compact sealed 18 inch subwoofer with strong deep bass for home theater and both balanced and RCA inputs. The tradeoff: The 533.4H x 533.4W x 457.2D mm cabinet and 117.1 lbs (53.1 kg) mass make this a serious placement and moving commitment.
Buy the JTR Speakers Captivator RS1 new; the Monoprice Monolith 16 THX Ultra is no longer sold new, so it only makes sense as a used find.
Still deciding? The full Subwoofers rankings cover every ranked option.
A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used.
A compact sealed 18 inch subwoofer with strong deep bass for home theater and both balanced and RCA inputs.
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.
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Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | JTR Speakers Captivator RS1 | |
|---|---|---|
| Price | $2,300 Discontinued | $3,300 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #56 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | sealed |
| Output SPL at 15 Hz | 107.3 dB | 105.4 dB |
| Output SPL at 20 Hz | 118.4 dB | 111.1 dB |
| Output SPL at 25 Hz | 123.3 dB | 115.5 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 119.6 dB |
| Output SPL at 40 Hz | 126.3 dB | 121.3 dB |
| Output SPL at 50 Hz | 126.5 dB | 122.0 dB |
| Output SPL at 63 Hz | 126.6 dB | 122.1 dB |
| Output SPL at 80 Hz | 126.8 dB | 121.9 dB |
| Output SPL at 100 Hz | 127.2 dB | 121.9 dB |
| Output SPL at 125 Hz | 127.6 dB | 121.9 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 121.8 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 21”H x 21”W x 18”D (533.4 x 533.4 x 457.2 mm) |
| Weight | 171.5 lbs (77.8 kg) | 117.1 lbs (53.1 kg) |
| Warranty | 5 | 5/3 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 16” (406mm) driver | 18” (457mm) driver |
| Inputs | XLR, RCA, XLR out | XLR, RCA |
| 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 |
| Output SPL at 10 Hz | - | 96.1 dB |
| Output SPL at 12.5 Hz | - | 100.1 dB |
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