Short answer: both are discontinued, so this only matters if you are buying used. Used, the SVS PB-4000 is the better pick: it ranks #69 of 143 subwoofers by sound quality (rated 4.2/5), against #88 (rated 4.1/5) for the Monoprice Monolith M15-S. If you want one new, the SVS PB-5000 R-Evolution replaces the SVS PB-4000 and is rated 4.2/5 at $2,399.
Buy the SVS PB-4000 only if you find one used in good condition; both are discontinued, and it is the better rated of the two. For a new speaker, buy the SVS PB-5000 R-Evolution, which replaces the SVS PB-4000.
Want more options? Browse the full Subwoofers rankings.
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Specifications Side By Side
| Monoprice Monolith M15-S | SVS PB-4000 | |
|---|---|---|
| Price | $999 Discontinued | $2,158.97 Discontinued |
| Ranked | #88 of 143 in Large Home Subwoofers (Over 75 lbs) | #69 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, front |
| Output SPL at 15 Hz | 100.1 dB | 102.1 dB |
| Output SPL at 20 Hz | 105.6 dB | 115.3 dB |
| Output SPL at 25 Hz | 111.2 dB | 116.3 dB |
| Output SPL at 31.5 Hz | 115.2 dB | 117.8 dB |
| Output SPL at 40 Hz | 118.4 dB | 119.8 dB |
| Output SPL at 50 Hz | 119.3 dB | 121.7 dB |
| Output SPL at 63 Hz | 119.6 dB | 120.7 dB |
| Output SPL at 80 Hz | 118.9 dB | 119.2 dB |
| Output SPL at 100 Hz | 119.1 dB | 118.1 dB |
| Output SPL at 125 Hz | 118.9 dB | 117.5 dB |
| CEA-2010-A Average (40-80Hz) | 119.0 dB | 120.3 dB |
| Dimensions | 23.5”H x 16.7”W x 19.7”D (596.9 x 424.2 x 500.4 mm) | 23.4”H x 20.5”W x 27.7”D (594.4 x 520.7 x 703.6 mm) |
| Warranty | 5 | 5 |
| Country | United States | United States |
| Measurement Source | Manufacturer | Audioholics |
| Weight | 80 lbs (36.3 kg) | 153.2 lbs (69.5 kg) |
| Drivers | 15” (381mm) driver | 13.5” (343mm) driver with ported design |
| Cabinet Color | - | black |
| Inputs | - | XLR (balanced), RCA (LFE/stereo) |
| 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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