Short answer: these are two serious sealed subwoofers with different priorities: HSU brings a larger 15-inch platform, while Rythmik uses servo control in a compact 12-inch design. Both are aimed at tight, accurate bass rather than the maximum low-end output of a ported enclosure.
Buy the HSU Research ULS-15 MK2 if you want the larger sealed driver platform for deep, controlled bass.
Buy the Rythmik F12 if servo-controlled bass and a compact sealed cabinet suit your system better.
Looking for alternatives? See the complete Subwoofers rankings.
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Specifications Side By Side
| HSU Research ULS-15 MK2 | Rythmik F12 | |
|---|---|---|
| Price | $999.00 | $1,439 |
| Ranked | #4 of 212 in Medium Home Subwoofers (30-75 lbs) | #21 of 212 in Medium 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 | - |
| Output SPL at 20 Hz | 102.4 dB | 103.6 dB |
| Output SPL at 25 Hz | 107.7 dB | 106.7 dB |
| Output SPL at 31.5 Hz | 113.4 dB | 113.5 dB |
| Output SPL at 40 Hz | 118.3 dB | 118.3 dB |
| Output SPL at 50 Hz | 120.8 dB | 119.1 dB |
| Output SPL at 63 Hz | 121.2 dB | 120.4 dB |
| Output SPL at 80 Hz | 121.1 dB | 119.6 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 | 119.3 dB |
| Dimensions | 19”H x 18”W x 19.5”D (482.6 x 457.2 x 495.3 mm) | 15.7”H x 15.7”W x 17”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 |
| Amplifier Power | 600W RMS / 2000W peak | 370W RMS |
| Crossover Frequency | 30-90Hz adjustable | - |
| Phase Control | 0°-180° | - |
| Features | Q control, sealed subwoofer, EQ1/EQ2 modes | - |
| Drivers | 15” (381mm) driver | 12” (305mm) driver |
| Output SPL at 16 Hz | - | 101.0 dB |
| Inputs | - | XLR (2), RCA (line/LFE) |
| XLR Input | - | Yes |
| RCA Input | - | Yes |
| TRS Input | - | No |
| Optical Input | - | No |
| Coaxial Input | - | No |
| USB Input | - | No |
| HDMI Input | - | No |
| AES Input | - | No |
| Aux Input | - | No |
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