Short answer: the Monoprice Monolith 16 THX Ultra. It ranks #18 of 110 subwoofers by sound quality at $2300; the Rythmik FV25HP ranks #22 and costs $2499, so there is little reason to consider the other one.
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 Rythmik FV25HP offers: Independent CEA-2010 testing records 116.6 dB at 20 Hz and 126.2 dB through 40-80 Hz. The ported, front enclosure with 2x 15” (381mm) driver has the headroom for demanding film bass in a large room. Watch for: The 1054.1H x 533.4W x 558.8D mm cabinet and 95.3 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Buy the Monoprice Monolith 16 THX Ultra. It ranks higher for sound quality than the Rythmik FV25HP and costs less, so the other one has nothing left to offer.
Still deciding? The full Subwoofers rankings cover every ranked option.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | Rythmik FV25HP | |
|---|---|---|
| Price | $2,300 | $2499 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #22 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | 113.2 dB |
| Output SPL at 20 Hz | 118.4 dB | 116.6 dB |
| Output SPL at 25 Hz | 123.3 dB | 119.1 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 122.4 dB |
| Output SPL at 40 Hz | 126.3 dB | 124.7 dB |
| Output SPL at 50 Hz | 126.5 dB | 126.1 dB |
| Output SPL at 63 Hz | 126.6 dB | 126.7 dB |
| Output SPL at 80 Hz | 126.8 dB | 127.3 dB |
| Output SPL at 100 Hz | 127.2 dB | 127.9 dB |
| Output SPL at 125 Hz | 127.6 dB | 127.8 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 126.2 dB |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) | 41.5"H x 21"W x 22"D (1054.1 x 533.4 x 558.8 mm) |
| Weight | 171.5 lbs (77.8 kg) | 210.1 lbs (95.3 kg) |
| Warranty | 5 | 5/3 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Data-bass |
| Drivers | 16" (406mm) driver | 2x 15" (381mm) driver |
| Output SPL at 10 Hz | - | 99.7 dB |
| Output SPL at 12.5 Hz | - | 108.4 dB |
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Prices on this page were last checked September 14, 2026 at 1:47 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
- Monoprice Monolith 16 THX Ultra vs Harbottle Audio C24 L2
- Monoprice Monolith 16 THX Ultra vs Funk Audio Ultra 21.0LX
- Monoprice Monolith 16 THX Ultra vs Funk Audio Classic 18.0
- Monoprice Monolith 16 THX Ultra vs JTR Speakers Captivator 2400
- Monoprice Monolith 16 THX Ultra vs Reaction Audio PV-15X
- Monoprice Monolith 16 THX Ultra vs Harbinger V2218S
- Monoprice Monolith 16 THX Ultra vs Danley Sound Labs DTS10
- Monoprice Monolith 16 THX Ultra vs Monoprice Monolith M-215
- See all 54 comparisons
Rythmik FV25HP: $2499 eBay
Pros: Independent CEA-2010 testing records 116.6 dB at 20 Hz and 126.2 dB through 40-80 Hz. The ported, front enclosure with 2x 15” (381mm) driver has the headroom for demanding film bass in a large room.
Cons: The 1054.1H x 533.4W x 558.8D mm cabinet and 95.3 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Full Rythmik FV25HP review and specifications →
| CEA-2010-A Average (40-80Hz) | 126.2 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 41.5"H x 21"W x 22"D (1054.1 x 533.4 x 558.8 mm) |
| Drivers | 2x 15" (381mm) driver |
| Enclosure | ported, front |
| Measurement Source | Data-bass |
| Output SPL at 10 Hz | 99.7 dB |
| Output SPL at 12.5 Hz | 108.4 dB |
| Output SPL at 15 Hz | 113.2 dB |
| Output SPL at 20 Hz | 116.6 dB |
| Output SPL at 25 Hz | 119.1 dB |
| Output SPL at 31.5 Hz | 122.4 dB |
| Output SPL at 40 Hz | 124.7 dB |
| Output SPL at 50 Hz | 126.1 dB |
| Output SPL at 63 Hz | 126.7 dB |
| Output SPL at 80 Hz | 127.3 dB |
| Output SPL at 100 Hz | 127.9 dB |
| Output SPL at 125 Hz | 127.8 dB |
| Warranty | 5/3 |
| Weight | 210.1 lbs (95.3 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Data-bass; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons