Short answer: the Monoprice Monolith 16 THX Ultra. It ranks #18 of 110 subwoofers by sound quality at $2300; the BK Electronics Extreme ranks #106 and costs $5995, which makes this an easy call rather than a real tradeoff.
What the Monoprice Monolith 16 THX Ultra offers: 16-inch ported driver and THX Ultra certification deliver 126.5dB CEA-2010-A average at a fraction of the price of the subwoofers ranked above it. Watch for: Heavy at 78 kg and ported design can interact with room acoustics.
What the BK Electronics Extreme offers: Massive 15-inch with 1000W RMS delivers startling speed like fast car with powerful engine. Continuous 0-180 degree phase control for flexible system integration. Beautiful compact design aids placement in listening room. Watch for: No detailed measurement caveats are currently recorded.
Buy the Monoprice Monolith 16 THX Ultra. It ranks higher for sound quality than the BK Electronics Extreme and costs less, so there is no real case for the other one.
Skip the BK Electronics Extreme if sound quality matters to you. It ranks near the bottom of the 110 subwoofers.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | BK Electronics Extreme | |
|---|---|---|
| Price | $2,300 | $5995 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #106 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | - |
| Output SPL at 15 Hz | 107.3 dB | 92.8 dB |
| Output SPL at 20 Hz | 118.4 dB | 100.7 dB |
| Output SPL at 25 Hz | 123.3 dB | 106.6 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 110.7 dB |
| Output SPL at 40 Hz | 126.3 dB | 111.4 dB |
| Output SPL at 50 Hz | 126.5 dB | 111.1 dB |
| Output SPL at 63 Hz | 126.6 dB | 110.5 dB |
| Output SPL at 80 Hz | 126.8 dB | 109.0 dB |
| Output SPL at 100 Hz | 127.2 dB | - |
| Output SPL at 125 Hz | 127.6 dB | - |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 110.5 dB |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) | - |
| Weight | 171.5 lbs (77.8 kg) | 200.6 lbs (91 kg) |
| Warranty | 5 | - |
| Cabinet Color | black | - |
| Country | United States | United Kingdom |
| Measurement Source | Audioholics | Ilkka Rissanen |
| Drivers | 16" (406mm) driver | 15" (381mm) driver |
| Amplifier Power | - | 1000W RMS |
| Frequency Response | - | Not specified |
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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
Monoprice Monolith 16 THX Ultra: $2,300 eBay
Pros: 16-inch ported driver and THX Ultra certification deliver 126.5dB CEA-2010-A average at a fraction of the price of the subwoofers ranked above it.
Cons: Heavy at 78 kg and ported design can interact with room acoustics.
Notes: Product # 42031
Full Monoprice Monolith 16 THX Ultra review and specifications →
| CEA-2010-A Average (40-80Hz) | 126.5 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) |
| Drivers | 16" (406mm) driver |
| Enclosure | ported, front |
| Measurement Source | Audioholics |
| Output SPL at 15 Hz | 107.3 dB |
| Output SPL at 20 Hz | 118.4 dB |
| Output SPL at 25 Hz | 123.3 dB |
| Output SPL at 31.5 Hz | 125.1 dB |
| Output SPL at 40 Hz | 126.3 dB |
| Output SPL at 50 Hz | 126.5 dB |
| Output SPL at 63 Hz | 126.6 dB |
| Output SPL at 80 Hz | 126.8 dB |
| Output SPL at 100 Hz | 127.2 dB |
| Output SPL at 125 Hz | 127.6 dB |
| Warranty | 5 |
| Weight | 171.5 lbs (77.8 kg) |
- 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
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BK Electronics Extreme: $5995 eBay
Pros: Massive 15-inch with 1000W RMS delivers startling speed like fast car with powerful engine. Continuous 0-180 degree phase control for flexible system integration. Beautiful compact design aids placement in listening room.
Full BK Electronics Extreme review and specifications →
| Amplifier Power | 1000W RMS |
|---|---|
| CEA-2010-A Average (40-80Hz) | 110.5 dB |
| Country | United Kingdom |
| Drivers | 15" (381mm) driver |
| Frequency Response | Not specified |
| Measurement Source | Ilkka Rissanen |
| Output SPL at 15 Hz | 92.8 dB |
| Output SPL at 20 Hz | 100.7 dB |
| Output SPL at 25 Hz | 106.6 dB |
| Output SPL at 31.5 Hz | 110.7 dB |
| Output SPL at 40 Hz | 111.4 dB |
| Output SPL at 50 Hz | 111.1 dB |
| Output SPL at 63 Hz | 110.5 dB |
| Output SPL at 80 Hz | 109.0 dB |
| Weight | 200.6 lbs (91 kg) |
- Reviews, Comparisons and Sound Samples
- Independently measured by Ilkka Rissanen; the published figures above come from this ASR subwoofer measurement thread.