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 $2,599.
Why pick the BK Electronics Monolith-DF: Independent CEA-2010 testing records 102.0 dB at 20 Hz and 108.4 dB through 40-80 Hz. 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. Independent CEA-2010 testing records 115.3 dB at 20 Hz and 120.3 dB through 40-80 Hz. 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.
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 |
Related Speaker Comparisons
How SVS PB-4000 compares with other leading options:
- JTR Speakers Orbit Shifter PRO vs SVS PB-4000
- JTR Speakers Orbit Shifter LFU vs SVS PB-4000
- Power Sound Audio (PSA) TRIAX vs SVS PB-4000
- JTR Speakers Captivator 4000ULF vs SVS PB-4000
- JTR Speakers Captivator S2 vs SVS PB-4000
Prices 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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The Two Speakers In Full
BK Electronics Monolith-DF: £406.95 Discontinued eBay
Pros: Independent CEA-2010 testing records 102.0 dB at 20 Hz and 108.4 dB through 40-80 Hz. The ported, bottom enclosure with 12” (305mm) driver with ported design delivers substantial upper-bass output for movie effects and music.
Cons: 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 603.8H x 539.8W x 419.9D mm cabinet and 46.8 kg mass still require deliberate placement and calibration. Discontinued.
Full BK Electronics Monolith-DF review and specifications →
| AES Input | No |
|---|---|
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 108.4 dB |
| Cabinet Color | black, wood |
| Coaxial Input | No |
| Country | United Kingdom |
| Dimensions | 23.8”H x 21.3”W x 16.5”D (603.8 x 539.8 x 419.9 mm) |
| Drivers | 12” (305mm) driver with ported design |
| Enclosure | ported, bottom |
| HDMI Input | No |
| Inputs | XLR (balanced), RCA (unbalanced) |
| Measurement Source | Ilkka Rissanen |
| Optical Input | No |
| Output SPL at 15 Hz | 91.3 dB |
| Output SPL at 20 Hz | 102.0 dB |
| Output SPL at 25 Hz | 106.4 dB |
| Output SPL at 31.5 Hz | 108.3 dB |
| Output SPL at 40 Hz | 108.6 dB |
| Output SPL at 50 Hz | 108.7 dB |
| Output SPL at 63 Hz | 108.6 dB |
| Output SPL at 80 Hz | 107.7 dB |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | No |
| Warranty | 2 |
| Weight | 103.2 lbs (46.8 kg) |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Ilkka Rissanen; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- BK Electronics Monolith-DF vs SVS SB13-Plus
- BK Electronics Monolith-DF vs Genelec HTS4B
- BK Electronics Monolith-DF vs RSL (Rogersound Labs) Speedwoofer 12S
- BK Electronics Monolith-DF vs HSU Research VTF-3 MK3
- BK Electronics Monolith-DF vs Rythmik F18
- BK Electronics Monolith-DF vs HSU Research VTF-3 MK5 HP
- BK Electronics Monolith-DF vs Rythmik FV15HP
- BK Electronics Monolith-DF vs JTR Speakers Captivator 1400
- See all 16 comparisons
SVS PB-4000: $2,158.97 Discontinued Amazon $2,158.97 eBay
Newer model: the SVS PB-5000 R-Evolution, ranked lower, estimated 4.2/5, released Apr 2025. See every SVS subwoofers generation.
Same family: the SVS PB-1000 (smaller subwoofer, rated 3.6/5), the SVS PB-2000 (smaller subwoofer, rated 4.1/5), the SVS PB-3000 (smaller subwoofer, ranked higher, rated 4.2/5), the SVS SB-1000 (larger subwoofer, rated 3.9/5), the SVS SB-2000 (larger subwoofer, rated 3.9/5), the SVS SB-3000 (larger subwoofer, rated 4.1/5), the SVS SB-4000 (larger subwoofer, ranked lower, rated 4.2/5) and the SVS PC-2000 (larger subwoofer, rated 3.7/5).
Pros: Independent CEA-2010 testing records 115.3 dB at 20 Hz and 120.3 dB through 40-80 Hz. The ported, front enclosure with 13.5” (343mm) driver with ported design has the headroom for demanding film bass in a large room.
Cons: The 594.4H x 520.7W x 703.6D mm cabinet and 69.5 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential. Discontinued.
Full SVS PB-4000 review and specifications →
| Released | Jan 2018 (8 years ago) |
|---|---|
| AES Input | No |
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 120.3 dB |
| Cabinet Color | black |
| Coaxial Input | No |
| Country | United States |
| Dimensions | 23.4”H x 20.5”W x 27.7”D (594.4 x 520.7 x 703.6 mm) |
| Drivers | 13.5” (343mm) driver with ported design |
| Enclosure | ported, front |
| HDMI Input | No |
| Inputs | XLR (balanced), RCA (LFE/stereo) |
| Measurement Source | Audioholics |
| Optical Input | No |
| Output SPL at 15 Hz | 102.1 dB |
| Output SPL at 20 Hz | 115.3 dB |
| Output SPL at 25 Hz | 116.3 dB |
| Output SPL at 31.5 Hz | 117.8 dB |
| Output SPL at 40 Hz | 119.8 dB |
| Output SPL at 50 Hz | 121.7 dB |
| Output SPL at 63 Hz | 120.7 dB |
| Output SPL at 80 Hz | 119.2 dB |
| Output SPL at 100 Hz | 118.1 dB |
| Output SPL at 125 Hz | 117.5 dB |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | No |
| Warranty | 5 |
| Weight | 153.2 lbs (69.5 kg) |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Audioholics; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- SVS PB-4000 vs SVS SB-4000
- SVS PB-4000 vs Monoprice Monolith M-15 V2
- SVS PB-4000 vs SVS PB-5000 R-Evolution
- SVS PB-4000 vs HSU Research VTF-3 MK5 HP
- SVS PB-4000 vs HSU Research VTF-15H MK2
- SVS PB-4000 vs Rythmik FV15HP
- SVS PB-4000 vs Rythmik F18
- SVS PB-4000 vs Monoprice Monolith M15-S
- See all 25 comparisons