Short answer: the REL Acoustics S/850, if you are buying new. The REL Acoustics R-528 ranks higher than the KEF KC92 (#95 vs #203 of 212 subwoofers) but is discontinued; its replacement, the REL Acoustics S/850, is rated 3.7/5 at $3,999 and is still sold new.
What the KEF KC92 does well: A compact sealed subwoofer with twin back to back 9 inch drivers, a 1,000 watt amp and an optional wireless adapter, best for music. The catch: No independent measurements yet, so its output can’t be compared with ranked subwoofers.
The REL Acoustics R-528 is the better-sounding option. A compact 12 inch subwoofer with a passive radiator, a strong amp and premium finish, now discontinued. Watch for: It is expensive for its measured output, which is 112.8dB from 40 to 80Hz and only 92.7dB at 25Hz.
Buy the REL Acoustics S/850, the replacement for the discontinued REL Acoustics R-528; it is rated higher for sound quality than the KEF KC92.
Worth knowing: the KEF KC92 has not been measured yet. Its rating is estimated from related models, with a likely range of 2.8 to 3.2, so treat this verdict as provisional.
Looking for alternatives? See the complete Subwoofers rankings.
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Specifications Side By Side
| KEF KC92 | REL Acoustics R-528 | |
|---|---|---|
| Price | $2,449.95 | $1,999 Discontinued |
| Ranked | #203 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated | #95 of 212 in Medium Home Subwoofers (30-75 lbs) |
| Warranty | 5/2 | 3 |
| Enclosure | sealed | passive radiator |
| Drivers | 2x 9” drivers, force-cancelling | 12” (305mm) driver |
| Amplifier Power | 1000W RMS (2 x 500W) | 500W RMS |
| Frequency Response | 11-200Hz, ±3dB | 21Hz-6dB |
| Maximum SPL | 110dB (manufacturer specified) | - |
| Dimensions | 13.9”H x 13”W x 14.2”D (352.5 x 330 x 360.5 mm) | 17.5”H x 15.5”W x 17.2”D (444.5 x 393.7 x 436.9 mm) |
| Weight | 44.1 lbs (20.0 kg) | 58 lbs (26.3 kg) |
| Cabinet Color | Black Gloss, White Gloss | - |
| Country | United Kingdom | United Kingdom |
| Output SPL at 25 Hz | - | 92.7 dB |
| Output SPL at 31.5 Hz | - | 106.5 dB |
| Output SPL at 40 Hz | - | 111.0 dB |
| Output SPL at 50 Hz | - | 112.7 dB |
| Output SPL at 63 Hz | - | 114.6 dB |
| CEA-2010-A Average (40-80Hz) | - | 112.8 dB (avg of 3/4 bands) |
| Measurement Source | - | Brent Butterworth |
Where the Ratings Come From
- KEF KC92: manufacturer specifications and listening comparisons; no independent measurement has been published yet.
- REL Acoustics R-528: 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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