Short answer: the RSL (Rogersound Labs) Speedwoofer 12S, if you are buying new. The Monoprice Monolith 16 THX Ultra ranks higher than it (#19 vs #131 of 143 subwoofers, 4.4/5 vs 3.7/5) but is discontinued, so only consider it used; the RSL (Rogersound Labs) Speedwoofer 12S is still sold new at $884.96.
The Monoprice Monolith 16 THX Ultra is the better-sounding choice. 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.
What the RSL (Rogersound Labs) Speedwoofer 12S does well: An affordable rear ported 12 inch subwoofer with strong deep bass output for movies. The catch: The 565.1H x 479.4W x 562.0D mm cabinet and 82 lbs (37.2 kg) mass make this a serious placement and moving commitment.
Buy the RSL (Rogersound Labs) Speedwoofer 12S 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.
An affordable rear ported 12 inch subwoofer with strong deep bass output for movies.
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 | RSL (Rogersound Labs) Speedwoofer 12S | |
|---|---|---|
| Price | $2,300 Discontinued | $884.96 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #131 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, rear |
| Output SPL at 15 Hz | 107.3 dB | 104.4 dB |
| Output SPL at 20 Hz | 118.4 dB | 109.3 dB |
| Output SPL at 25 Hz | 123.3 dB | 110.9 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 112.5 dB |
| Output SPL at 40 Hz | 126.3 dB | 113.4 dB |
| Output SPL at 50 Hz | 126.5 dB | 113.4 dB |
| Output SPL at 63 Hz | 126.6 dB | 113.0 dB |
| Output SPL at 80 Hz | 126.8 dB | 113.1 dB |
| Output SPL at 100 Hz | 127.2 dB | 112.2 dB |
| Output SPL at 125 Hz | 127.6 dB | - |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 113.2 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 22.2”H x 18.9”W x 22.1”D (565.1 x 479.4 x 562.0 mm) |
| Weight | 171.5 lbs (77.8 kg) | 82 lbs (37.2 kg) |
| Warranty | 5 | 5/3 |
| Cabinet Color | black | black, white |
| Country | United States | United States |
| Measurement Source | Audioholics | ErinsAudioCorner |
| Drivers | 16” (406mm) driver | 12” (305mm) 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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