Short answer: the HSU Research ULS-15 MK2. It ranks #4 of 212 subwoofers by sound quality, rated 4.2/5, at $999. The Sonos Sub 4 ranks #10, rated 3.7/5, at $899, $100 cheaper, a saving that is not big enough to make up the sound-quality gap.
What the Sonos Sub 4 does well: A wireless subwoofer for Sonos soundbars and speakers, with force-cancelling drivers and setup from the Sonos app, placed near any outlet. Watch for: No independent measurements yet, so its output can’t be compared with ranked subwoofers.
Why pick the HSU Research ULS-15 MK2: A sealed 15 inch subwoofer with tight, accurate bass, a great value in large subs. The tradeoff: No phone app or room correction, so setup is manual, and it ships in a plain vinyl finish where a similarly priced SVS offers gloss black.
Buy the HSU Research ULS-15 MK2. It is rated higher for sound quality, and saving $100 with the Sonos Sub 4 does not make up for the sound-quality gap.
Worth knowing: the Sonos Sub 4 has not been measured yet. Its rating is estimated from related models, with a likely range of 3.5 to 3.9, so treat this verdict as provisional.
Want more options? Browse the full Subwoofers rankings.
Prices on this page were last checked November 14, 2026 at 6:17 PM 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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Specifications Side By Side
| Sonos Sub 4 | HSU Research ULS-15 MK2 | |
|---|---|---|
| Price | $899.00 | $999.00 |
| Ranked | #10 of 73 in Small Home Subwoofers (Under 30 lbs) Estimated | #4 of 212 in Medium Home Subwoofers (30-75 lbs) |
| Weight | 26 lbs (11.79 kg) | 65 lbs (29.5 kg) |
| Dimensions | 15.3”H x 15.8”W x 6.2”D (389 x 402 x 158 mm) | 19”H x 18”W x 19.5”D (482.6 x 457.2 x 495.3 mm) |
| Warranty | 1 | 7/2(+3) |
| Enclosure | ported, force-cancelling | sealed |
| Drivers | 2x force-cancelling drivers | 15” (381mm) driver |
| Frequency Response | 25Hz extension (manufacturer specified) | 20-200Hz, ±1dB |
| Cabinet Color | black, white | black, wood |
| Country | United States | United States |
| 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 |
| CEA-2010-A Average (40-80Hz) | - | 120.3 dB |
| Measurement Source | - | Audioholics |
| Amplifier Power | - | 600W RMS / 2000W peak |
| Crossover Frequency | - | 30-90Hz adjustable |
| Phase Control | - | 0°-180° |
| Features | - | Q control, sealed subwoofer, EQ1/EQ2 modes |
Where the Ratings Come From
- Sonos Sub 4: manufacturer specifications and listening comparisons; no independent measurement has been published yet.
- HSU Research ULS-15 MK2: manufacturer specifications and listening comparisons; no independent measurement has been published yet.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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