Short answer: the REL Acoustics HT/1510 Predator II, if you are buying new. The Monoprice Monolith 16 THX Ultra ranks higher than it (#19 vs #98 of 143 subwoofers, 4.4/5 vs 4.1/5) but is discontinued, so only consider it used; the REL Acoustics HT/1510 Predator II is still sold new at $1,799.
The Monoprice Monolith 16 THX Ultra is the better-sounding pick. 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 REL Acoustics HT/1510 Predator II does well: A sealed 15 inch home theater subwoofer with strong, punchy upper bass for movie effects and 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 REL Acoustics HT/1510 Predator II, since the Monoprice Monolith 16 THX Ultra is discontinued and only worth hunting down used.
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 sealed 15 inch home theater subwoofer with strong, punchy upper bass for movie effects and 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 | REL Acoustics HT/1510 Predator II | |
|---|---|---|
| Price | $2,300 Discontinued | $1,799.00 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #98 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | sealed |
| Output SPL at 15 Hz | 107.3 dB | 91.4 dB |
| Output SPL at 20 Hz | 118.4 dB | 98.0 dB |
| Output SPL at 25 Hz | 123.3 dB | 104.4 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 111.1 dB |
| Output SPL at 40 Hz | 126.3 dB | 116.9 dB |
| Output SPL at 50 Hz | 126.5 dB | 118.5 dB |
| Output SPL at 63 Hz | 126.6 dB | 118.5 dB |
| Output SPL at 80 Hz | 126.8 dB | 118.4 dB |
| Output SPL at 100 Hz | 127.2 dB | 118.5 dB |
| Output SPL at 125 Hz | 127.6 dB | 118.0 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 118.1 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 18”H x 21.3”W x 19.4”D (457.2 x 541.0 x 492.8 mm) |
| Weight | 171.5 lbs (77.8 kg) | 99.6 lbs (45.2 kg) |
| Warranty | 5 | 3 |
| Cabinet Color | black | black |
| Country | United States | United Kingdom |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 16” (406mm) driver | 15” (381mm) driver |
| Inputs | XLR, RCA, XLR out | - |
| 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 | - |
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