Short answer: the Funk Audio Ultra 24.0 on measured sound quality, the BK Electronics Monolith-DF on price. The Funk Audio Ultra 24.0 ranks #11 of 110 subwoofers at $9761.14. The BK Electronics Monolith-DF ranks #107 at $8995, $766.14 cheaper.
What the BK Electronics Monolith-DF offers: 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. Watch for: 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.
What the Funk Audio Ultra 24.0 offers: Published CEA-2010 specifications list 120.0 dB at 20 Hz and 127.9 dB through 40-80 Hz. The sealed enclosure with 24” (610mm) driver has the headroom for demanding film bass in a large room. Watch for: The 787.4H x 660.4W x 609.6D mm cabinet and 135 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Buy the BK Electronics Monolith-DF when the price outweighs sound quality for you, and the Funk Audio Ultra 24.0 when sound quality outweighs the price instead.
If sound quality matters at all to you, skip the BK Electronics Monolith-DF. It ranks near the bottom of the 110 subwoofers, so look higher up the list instead.
Still deciding? The full Subwoofers rankings cover every ranked option.
Specifications Side By Side
| BK Electronics Monolith-DF | Funk Audio Ultra 24.0 | |
|---|---|---|
| Price | $8995 | $9,761.14 |
| Ranked | #107 of 110 in Large Home Subwoofers (Over 75 lbs) | #11 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, bottom | sealed |
| Output SPL at 15 Hz | 91.3 dB | 111.8 dB |
| Output SPL at 20 Hz | 102.0 dB | 120.0 dB |
| Output SPL at 25 Hz | 106.4 dB | 122.0 dB |
| Output SPL at 31.5 Hz | 108.3 dB | 123.0 dB |
| Output SPL at 40 Hz | 108.6 dB | 127.1 dB |
| Output SPL at 50 Hz | 108.7 dB | 129.9 dB |
| Output SPL at 63 Hz | 108.6 dB | 127.6 dB |
| Output SPL at 80 Hz | 107.7 dB | 127.0 dB |
| CEA-2010-A Average (40-80Hz) | 108.4 dB | 127.9 dB |
| Dimensions | 23.8"H x 21.3"W x 16.5"D (603.8 x 539.8 x 419.9 mm) | 31"H x 26"W x 24"D (787.4 x 660.4 x 609.6 mm) |
| Weight | 103.2 lbs (46.8 kg) | 297.6 lbs (135 kg) |
| Warranty | 2 | 3 |
| Cabinet Color | black, wood | wood, custom |
| Country | United Kingdom | Canada |
| Measurement Source | Ilkka Rissanen | Manufacturer |
| Drivers | 12" (305mm) driver with ported design | 24" (610mm) driver |
| Output SPL at 10 Hz | - | 101.0 dB |
| Output SPL at 12.5 Hz | - | 104.9 dB |
| Output SPL at 100 Hz | - | 128.2 dB |
Related Speaker Comparisons
More worthwhile head-to-heads for Funk Audio Ultra 24.0:
- Funk Audio Ultra 24.0 vs JTR Speakers Captivator S2
- Funk Audio Ultra 24.0 vs Power Sound Audio (PSA) V3600I
- Funk Audio Custom 21.0 vs Funk Audio Ultra 24.0
- JTR Speakers Growler (2015) vs Funk Audio Ultra 24.0
- Harbinger V2218S vs Funk Audio Ultra 24.0
Prices on this page were last checked September 16, 2026 at 12:41 AM 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: $8995 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.
Full BK Electronics Monolith-DF review and specifications →
| CEA-2010-A Average (40-80Hz) | 108.4 dB |
|---|---|
| Cabinet Color | black, wood |
| 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 |
| Measurement Source | Ilkka Rissanen |
| 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 |
| Warranty | 2 |
| Weight | 103.2 lbs (46.8 kg) |
- 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 SVS PB-4000
- BK Electronics Monolith-DF vs HSU Research VTF-3 MK5 HP
- BK Electronics Monolith-DF vs Rythmik FV15HP
- See all 16 comparisons
Funk Audio Ultra 24.0: $9,761.14 eBay
Pros: Published CEA-2010 specifications list 120.0 dB at 20 Hz and 127.9 dB through 40-80 Hz. The sealed enclosure with 24” (610mm) driver has the headroom for demanding film bass in a large room.
Cons: The 787.4H x 660.4W x 609.6D mm cabinet and 135 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Full Funk Audio Ultra 24.0 review and specifications →
| CEA-2010-A Average (40-80Hz) | 127.9 dB |
|---|---|
| Cabinet Color | wood, custom |
| Country | Canada |
| Dimensions | 31"H x 26"W x 24"D (787.4 x 660.4 x 609.6 mm) |
| Drivers | 24" (610mm) driver |
| Enclosure | sealed |
| Measurement Source | Manufacturer |
| Output SPL at 10 Hz | 101.0 dB |
| Output SPL at 12.5 Hz | 104.9 dB |
| Output SPL at 15 Hz | 111.8 dB |
| Output SPL at 20 Hz | 120.0 dB |
| Output SPL at 25 Hz | 122.0 dB |
| Output SPL at 31.5 Hz | 123.0 dB |
| Output SPL at 40 Hz | 127.1 dB |
| Output SPL at 50 Hz | 129.9 dB |
| Output SPL at 63 Hz | 127.6 dB |
| Output SPL at 80 Hz | 127.0 dB |
| Output SPL at 100 Hz | 128.2 dB |
| Warranty | 3 |
| Weight | 297.6 lbs (135 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- These figures are manufacturer-specified rather than independently measured.
- Head-to-Head Comparisons
- Funk Audio Ultra 24.0 vs Funk Audio Custom 21.0
- Funk Audio Ultra 24.0 vs Power Sound Audio (PSA) V3600I
- Funk Audio Ultra 24.0 vs JTR Speakers Captivator S2
- Funk Audio Ultra 24.0 vs JTR Speakers Growler (2015)
- Funk Audio Ultra 24.0 vs Harbinger V2218S
- Funk Audio Ultra 24.0 vs Funk Audio Classic 18.0
- Funk Audio Ultra 24.0 vs Monoprice Monolith 16 THX Ultra
- Funk Audio Ultra 24.0 vs Rythmik FV25HP
- See all 17 comparisons