Short answer: the HSU Research ULS-15 MK2. It ranks #3 of 137 subwoofers at $1035; the Rythmik F12 ranks #51 and costs $1120, so there is not much of a tradeoff to weigh.
The case for the HSU Research ULS-15 MK2: Sealed design delivers tight, accurate bass with low bloat.
What the Rythmik F12 gets right: Sealed 12-inch servo with 370W RMS offers excellent value.
Buy the HSU Research ULS-15 MK2 if the ranking matters more than the price. Buy the Rythmik F12 if the price matters more than the ranking.
Specifications Side By Side
| HSU Research ULS-15 MK2 | Rythmik F12 | |
|---|---|---|
| Price | $1,035 | $1,120 |
| Ranked | #3 of 137 in Medium Powered Home Subwoofers (30-75 lbs) | #51 of 137 in Medium Powered Home Subwoofers (30-75 lbs) |
| Enclosure | sealed | sealed |
| Output SPL at 12.5 Hz | 93.7 dB | - |
| Output SPL at 15 Hz | 98.0 dB | 95.0 dB |
| Output SPL at 20 Hz | 102.4 dB | 97.6 dB |
| Output SPL at 25 Hz | 107.7 dB | 100.7 dB |
| Output SPL at 31.5 Hz | 113.4 dB | 107.5 dB |
| Output SPL at 40 Hz | 118.3 dB | 112.3 dB |
| Output SPL at 50 Hz | 120.8 dB | 113.1 dB |
| Output SPL at 63 Hz | 121.2 dB | 114.4 dB |
| Output SPL at 80 Hz | 121.1 dB | 113.6 dB |
| Output SPL at 100 Hz | 120.7 dB | - |
| Output SPL at 125 Hz | 120.7 dB | - |
| CEA-2010-A Average (40-80Hz) | 120.3 dB | 113.3 dB |
| Dimensions | 19.0"H x 18.0"W x 19.5"D (482.6 x 457.2 x 495.3 mm) | 15.75"H x 15.75"W x 17.0"D (400.0 x 400.0 x 431.8 mm) |
| Weight | 65 lbs / 29.5 kg | 75 lbs / 34.0 kg |
| Warranty | 7/2(+3) | 5/3 |
| Cabinet Color | black, wood | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Frequency Response | 20-200Hz, ±1dB | 14Hz extension |
| Power Output (Watts) | 600W RMS / 2000W peak | 370W RMS |
| Crossover | 30-90Hz adjustable | - |
| Phase Control | 0°-180° | - |
| Features | Q control, sealed subwoofer, EQ1/EQ2 modes | - |
| Drivers | 15" (381mm) driver | 12" (305mm) driver |
The Two Speakers In Full
HSU Research ULS-15 MK2: $1,035
Pros: Sealed design delivers tight, accurate bass with low bloat. 600W BASH amplifier. 30% less expensive and 20 lbs lighter than predecessor. Easy integration with Q and EQ controls. Great value in the 15” sub market at under $850 shipped.
Notes: Price includes shipping
| CEA-2010-A Average (40-80Hz) | 120.3 dB |
|---|---|
| Cabinet Color | black, wood |
| Country | United States |
| Crossover | 30-90Hz adjustable |
| Dimensions | 19.0"H x 18.0"W x 19.5"D (482.6 x 457.2 x 495.3 mm) |
| Drivers | 15" (381mm) driver |
| Enclosure | sealed |
| Features | Q control, sealed subwoofer, EQ1/EQ2 modes |
| Frequency Response | 20-200Hz, ±1dB |
| Measurement Source | Audioholics |
| Output SPL at 12.5 Hz | 93.7 dB |
| Output SPL at 15 Hz | 98.0 dB |
| Output SPL at 20 Hz | 102.4 dB |
| Output SPL at 25 Hz | 107.7 dB |
| Output SPL at 31.5 Hz | 113.4 dB |
| Output SPL at 40 Hz | 118.3 dB |
| Output SPL at 50 Hz | 120.8 dB |
| Output SPL at 63 Hz | 121.2 dB |
| Output SPL at 80 Hz | 121.1 dB |
| Output SPL at 100 Hz | 120.7 dB |
| Output SPL at 125 Hz | 120.7 dB |
| Phase Control | 0°-180° |
| Power Output (Watts) | 600W RMS / 2000W peak |
| Warranty | 7/2(+3) |
| Weight | 65 lbs / 29.5 kg |
- Head-to-Head Comparisons
- HSU Research ULS-15 MK2 vs MartinLogan Dynamo 1600X
- HSU Research ULS-15 MK2 vs Power Sound Audio (PSA) XV15
- HSU Research ULS-15 MK2 vs JTR Speakers Captivator 212PRO
- HSU Research ULS-15 MK2 vs Paradigm Defiance X12
- HSU Research ULS-15 MK2 vs Monoprice SW-15
- HSU Research ULS-15 MK2 vs SVS SB-3000
- HSU Research ULS-15 MK2 vs SVS PB-1000 PRO
- HSU Research ULS-15 MK2 vs Monoprice SW-12
- See all 14 comparisons
- Links
Rythmik F12: $1,120
Pros: Sealed 12-inch servo with 370W RMS offers excellent value. Very musical and can disappear in small rooms. Digs to 14Hz with excellent build quality and well-braced cabinet.
| CEA-2010-A Average (40-80Hz) | 113.3 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 15.75"H x 15.75"W x 17.0"D (400.0 x 400.0 x 431.8 mm) |
| Drivers | 12" (305mm) driver |
| Enclosure | sealed |
| Frequency Response | 14Hz extension |
| Measurement Source | Brent Butterworth |
| Output SPL at 15 Hz | 95.0 dB |
| Output SPL at 20 Hz | 97.6 dB |
| Output SPL at 25 Hz | 100.7 dB |
| Output SPL at 31.5 Hz | 107.5 dB |
| Output SPL at 40 Hz | 112.3 dB |
| Output SPL at 50 Hz | 113.1 dB |
| Output SPL at 63 Hz | 114.4 dB |
| Output SPL at 80 Hz | 113.6 dB |
| Power Output (Watts) | 370W RMS |
| Warranty | 5/3 |
| Weight | 75 lbs / 34.0 kg |
- Head-to-Head Comparisons
- Rythmik F12 vs RSL (Rogersound Labs) Speedwoofer 10S MKII
- Rythmik F12 vs SVS SB-2000
- Rythmik F12 vs Monoprice SW-12
- Rythmik F12 vs Klipsch R-121SW
- Rythmik F12 vs SVS PB-1000 PRO
- Rythmik F12 vs Monoprice Monolith M-10 V2
- Rythmik F12 vs SVS SB-3000
- Rythmik F12 vs Monoprice SW-15
- See all 14 comparisons
- Links
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Product prices and availability were last checked August 9, 2026 at 6:57 AM UTC 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.

