Short answer: the Pro Audio Technology LFC-24sm. It ranks #4 of 143 subwoofers by sound quality (rated 4.6/5) at $10,000 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. The catch: Heavy at 172 lbs (78 kg) and ported design can interact with room acoustics.
Why pick the Pro Audio Technology LFC-24sm: A giant 24 inch ported subwoofer with enormous deep bass output, built for large dedicated cinema rooms. The tradeoff: The 660.4H x 1536.7W x 533.4D mm cabinet and 266.1 lbs (120.7 kg) mass still need deliberate placement and calibration.
Buy the Pro Audio Technology LFC-24sm. It is rated higher for sound quality, and the Monoprice Monolith 16 THX Ultra is discontinued, so it is only available used.
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 giant 24 inch ported subwoofer with enormous deep bass output, built for large dedicated cinema 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
| Monoprice Monolith 16 THX Ultra | Pro Audio Technology LFC-24sm | |
|---|---|---|
| Price | $2,300 Discontinued | $10,000 Passive |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #4 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | - |
| Output SPL at 20 Hz | 118.4 dB | 123.7 dB |
| Output SPL at 25 Hz | 123.3 dB | 131.4 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 133.6 dB |
| Output SPL at 40 Hz | 126.3 dB | 135.4 dB |
| Output SPL at 50 Hz | 126.5 dB | 136.0 dB |
| Output SPL at 63 Hz | 126.6 dB | 135.2 dB |
| Output SPL at 80 Hz | 126.8 dB | - |
| Output SPL at 100 Hz | 127.2 dB | - |
| Output SPL at 125 Hz | 127.6 dB | - |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 135.5 dB (avg of 3/4 bands) |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 26”H x 60.5”W x 21”D (660.4 x 1536.7 x 533.4 mm) |
| Weight | 171.5 lbs (77.8 kg) | 266.1 lbs (120.7 kg) |
| Warranty | 5 | - |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 16” (406mm) driver | 24” (610mm) 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 | - |
| Passive | - | Yes |
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