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 #141 (rated 3.3/5) for the BK Electronics Monolith-DF. 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.
Why pick the BK Electronics Monolith-DF: A down ported 12 inch subwoofer with balanced XLR and RCA inputs at a low price, now discontinued. 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.
The SVS PB-4000 is the better-sounding option. A 13.5 inch ported subwoofer with very deep, strong bass for big home theaters and balanced and RCA inputs. The catch: The 594.4H x 520.7W x 703.6D mm cabinet and 153.2 lbs (69.5 kg) mass make this a serious placement and moving commitment.
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.
A down ported 12 inch subwoofer with balanced XLR and RCA inputs at a low price, now discontinued.
A 13.5 inch ported subwoofer with very deep, strong bass for big home theaters and balanced and RCA inputs.
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Specifications Side By Side
| BK Electronics Monolith-DF | SVS PB-4000 | |
|---|---|---|
| Price | £406.95 Discontinued | $2,158.97 Discontinued |
| Ranked | #141 of 143 in Large Home Subwoofers (Over 75 lbs) | #69 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, bottom | ported, front |
| Output SPL at 15 Hz | 91.3 dB | 102.1 dB |
| Output SPL at 20 Hz | 102.0 dB | 115.3 dB |
| Output SPL at 25 Hz | 106.4 dB | 116.3 dB |
| Output SPL at 31.5 Hz | 108.3 dB | 117.8 dB |
| Output SPL at 40 Hz | 108.6 dB | 119.8 dB |
| Output SPL at 50 Hz | 108.7 dB | 121.7 dB |
| Output SPL at 63 Hz | 108.6 dB | 120.7 dB |
| Output SPL at 80 Hz | 107.7 dB | 119.2 dB |
| CEA-2010-A Average (40-80Hz) | 108.4 dB | 120.3 dB |
| Dimensions | 23.8”H x 21.3”W x 16.5”D (603.8 x 539.8 x 419.9 mm) | 23.4”H x 20.5”W x 27.7”D (594.4 x 520.7 x 703.6 mm) |
| Weight | 103.2 lbs (46.8 kg) | 153.2 lbs (69.5 kg) |
| Warranty | 2 | 5 |
| Cabinet Color | black, wood | black |
| Country | United Kingdom | United States |
| Measurement Source | Ilkka Rissanen | Audioholics |
| Drivers | 12” (305mm) driver with ported design | 13.5” (343mm) driver with ported design |
| Inputs | XLR (balanced), RCA (unbalanced) | XLR (balanced), RCA (LFE/stereo) |
| XLR Input | Yes | Yes |
| RCA Input | Yes | Yes |
| TRS Input | No | No |
| Optical Input | No | No |
| Coaxial Input | No | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | No | No |
| Aux Input | No | No |
| Output SPL at 100 Hz | - | 118.1 dB |
| Output SPL at 125 Hz | - | 117.5 dB |
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