Short answer: the Monoprice Monolith M-215, if you are buying new. The Monoprice Monolith 16 THX Ultra measures as well as it (#19 vs #24 of 143 subwoofers, 4.4/5 vs 4.4/5) but is discontinued, so only consider it used; the Monoprice Monolith M-215 is still sold new at $2,999.99.
Buy the Monoprice Monolith M-215 if you want one new; the Monoprice Monolith 16 THX Ultra is discontinued, so only look for it used.
Still deciding? The full Subwoofers rankings cover every ranked option.
16-inch ported driver and THX Ultra certification deliver 126.5dB CEA-2010-A average at a fraction of the price of the subwoofers ranked above it.
eBay
Independent CEA-2010 testing records 118.9 dB at 20 Hz and 125.9 dB through 40-80 Hz.
Monoprice $2999.99 eBayPrices on this page were last checked October 15, 2026 at 5:41 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 | Monoprice Monolith M-215 | |
|---|---|---|
| Price | $2,300 Discontinued | $2999.99 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #24 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | 113.1 dB |
| Output SPL at 20 Hz | 118.4 dB | 118.9 dB |
| Output SPL at 25 Hz | 123.3 dB | 122.6 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 125.2 dB |
| Output SPL at 40 Hz | 126.3 dB | 126.4 dB |
| Output SPL at 50 Hz | 126.5 dB | 126.1 dB |
| Output SPL at 63 Hz | 126.6 dB | 125.6 dB |
| Output SPL at 80 Hz | 126.8 dB | 125.6 dB |
| Output SPL at 100 Hz | 127.2 dB | 125.7 dB |
| Output SPL at 125 Hz | 127.6 dB | 126.3 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 125.9 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 42.3”H x 20”W x 27.6”D (1074.4 x 508.0 x 701.0 mm) |
| Weight | 171.5 lbs (77.8 kg) | 216.1 lbs (98.0 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 16” (406mm) driver | 2x 15” (381mm) drivers |
| 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 | - |
| Output SPL at 12.5 Hz | - | 103.9 dB |
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