Short answer: both are discontinued, so this only matters if you are buying used. Used, the Harbinger V2218S is the better pick: it ranks #15 of 143 subwoofers by sound quality (rated 4.5/5), against #141 (rated 3.3/5) for the BK Electronics Monolith-DF. If you want one new, the JTR Speakers Orbit Shifter PRO ranks #1 at $4,499.
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.
The Harbinger V2218S is the better-sounding pick. A pro style 18 inch ported subwoofer with hard hitting upper bass for movie effects and music, relatively light for its output. 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.
Buy the Harbinger V2218S 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, start with the JTR Speakers Orbit Shifter PRO instead.
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 pro style 18 inch ported subwoofer with hard hitting upper bass for movie effects and music, relatively light for its output.
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Specifications Side By Side
| BK Electronics Monolith-DF | Harbinger V2218S | |
|---|---|---|
| Price | £406.95 Discontinued | $3,495 Discontinued |
| Ranked | #141 of 143 in Large Home Subwoofers (Over 75 lbs) | #15 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, bottom | ported, front |
| Output SPL at 15 Hz | 91.3 dB | - |
| Output SPL at 20 Hz | 102.0 dB | 81.7 dB |
| Output SPL at 25 Hz | 106.4 dB | 99.7 dB |
| Output SPL at 31.5 Hz | 108.3 dB | 118.0 dB |
| Output SPL at 40 Hz | 108.6 dB | 122.8 dB |
| Output SPL at 50 Hz | 108.7 dB | 129.0 dB |
| Output SPL at 63 Hz | 108.6 dB | 132.2 dB |
| Output SPL at 80 Hz | 107.7 dB | 131.7 dB |
| CEA-2010-A Average (40-80Hz) | 108.4 dB | 128.9 dB |
| Dimensions | 23.8”H x 21.3”W x 16.5”D (603.8 x 539.8 x 419.9 mm) | 32.5”H x 26.5”W x 29.7”D (825.5 x 673.1 x 754.4 mm) |
| Weight | 103.2 lbs (46.8 kg) | 89.9 lbs (40.8 kg) |
| Warranty | 2 | - |
| Cabinet Color | black, wood | black |
| Country | United Kingdom | United States |
| Measurement Source | Ilkka Rissanen | Brent Butterworth |
| Drivers | 12” (305mm) driver with ported design | 18” (457mm) driver |
| Inputs | XLR (balanced), RCA (unbalanced) | - |
| 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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