Short answer: the JTR Speakers Captivator 215PRO. It ranks #7 of 143 subwoofers by sound quality (rated 4.5/5) at $3,500 and is still sold new; the Monoprice Monolith 16 THX Ultra ranks #19 (rated 4.4/5) and is discontinued, so it is only an option used.
The case for 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.
What the JTR Speakers Captivator 215PRO does well: A tall dual 15 inch ported subwoofer with huge punch in the upper bass, great for hard hitting movie effects and loud music. 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 215PRO. It is rated higher for sound quality; the Monoprice Monolith 16 THX Ultra is no longer sold new.
Want more options? Browse the full Subwoofers rankings.
A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used.
A tall dual 15 inch ported subwoofer with huge punch in the upper bass, great for hard hitting movie effects and loud music.
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
| Monoprice Monolith 16 THX Ultra | JTR Speakers Captivator 215PRO | |
|---|---|---|
| Price | $2,300 Discontinued | $3,500 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #7 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | 103.6 dB |
| Output SPL at 20 Hz | 118.4 dB | 106.6 dB |
| Output SPL at 25 Hz | 123.3 dB | 122.1 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 126.8 dB |
| Output SPL at 40 Hz | 126.3 dB | 129.3 dB |
| Output SPL at 50 Hz | 126.5 dB | 131.2 dB |
| Output SPL at 63 Hz | 126.6 dB | 131.3 dB |
| Output SPL at 80 Hz | 126.8 dB | 130.9 dB |
| Output SPL at 100 Hz | 127.2 dB | 130.7 dB |
| Output SPL at 125 Hz | 127.6 dB | 131.1 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 130.7 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 40”H x 18”W x 30”D (1016.0 x 457.2 x 762.0 mm) |
| Weight | 171.5 lbs (77.8 kg) | 149 lbs (67.6 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 16” (406mm) driver | 2x 15” (381mm) drivers |
| 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 |
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