Short answer: both are discontinued, and they are rated the same for sound quality (#142 and #141 of 143 subwoofers). Either one is only an option used, so choose on condition and price. If you want one new, the JTR Speakers Orbit Shifter PRO ranks #1 at $4,499.
What the SVS SB13-Plus does well: A sealed 13 inch subwoofer with XLR and RCA inputs in a compact cube cabinet, now discontinued. The tradeoff: 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.
What the BK Electronics Monolith-DF does well: 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.
Buy the SVS SB13-Plus or the BK Electronics Monolith-DF, whichever you find used in better condition; both are discontinued. For a new speaker, start with the JTR Speakers Orbit Shifter PRO instead.
Still deciding? The full Subwoofers rankings cover every ranked option.
A sealed 13 inch subwoofer with XLR and RCA inputs in a compact cube cabinet, now discontinued.
A down ported 12 inch subwoofer with balanced XLR and RCA inputs at a low price, now discontinued.
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Specifications Side By Side
| SVS SB13-Plus | BK Electronics Monolith-DF | |
|---|---|---|
| Price | $1,399 Discontinued | £406.95 Discontinued |
| Ranked | #142 of 143 in Large Home Subwoofers (Over 75 lbs) | #141 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, bottom |
| Output SPL at 20 Hz | 92.3 dB | 102.0 dB |
| Output SPL at 25 Hz | 97.2 dB | 106.4 dB |
| Output SPL at 31.5 Hz | 97.2 dB | 108.3 dB |
| Output SPL at 40 Hz | 108.1 dB | 108.6 dB |
| Output SPL at 50 Hz | 108.1 dB | 108.7 dB |
| Output SPL at 63 Hz | 108.1 dB | 108.6 dB |
| CEA-2010-A Average (40-80Hz) | 108.1 dB (avg of 3/4 bands) | 108.4 dB |
| Dimensions | 17”H x 17”W x 18”D (431.8 x 431.8 x 457.2 mm) | 23.8”H x 21.3”W x 16.5”D (603.8 x 539.8 x 419.9 mm) |
| Weight | 95 lbs (43.1 kg) | 103.2 lbs (46.8 kg) |
| Warranty | 5 | 2 |
| Country | United States | United Kingdom |
| Measurement Source | Brent Butterworth | Ilkka Rissanen |
| Drivers | 13” (330mm) driver | 12” (305mm) driver with ported design |
| Inputs | XLR (balanced), RCA | XLR (balanced), RCA (unbalanced) |
| 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 15 Hz | - | 91.3 dB |
| Output SPL at 80 Hz | - | 107.7 dB |
| Cabinet Color | - | black, wood |
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