Short answer: the Sigberg Audio 10D. It ranks #36 of 212 subwoofers by sound quality, rated 3.9/5, at $4,067.37. The REL Acoustics S/850 ranks #110, rated 3.7/5, at $3,999, $68.37 cheaper, a saving that is not big enough to make up the sound-quality gap.
What the Sigberg Audio 10D does well: Dual 10-inch sealed with 500W RMS, 116.8dB average.
Why pick the REL Acoustics S/850: Front-firing 12 inch carbon and aluminum driver plus a down-firing 12 inch passive radiator, driven by an 850W RMS Class D amplifier (1,000W peak). The tradeoff: No independent measurements yet, so its output can’t be compared with ranked subwoofers; the rating is estimated from the measured REL Acoustics R-528, an older 12 inch REL that averaged 112.8dB in the CEA-2010 bands but fell to 92.7dB at 25Hz.
Buy the Sigberg Audio 10D. It is rated higher for sound quality, and the $68.37 saving on the REL Acoustics S/850 is not enough to make up the difference.
About the ratings: the REL Acoustics S/850’s rating is estimated from measured siblings and predecessors rather than its own measurements, with a likely range of 3.4 to 4.0, so this verdict could change once it is measured.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| Sigberg Audio 10D | REL Acoustics S/850 | |
|---|---|---|
| Price | $4,067.37 | $3,999.00 |
| Ranked | #36 of 212 in Medium Home Subwoofers (30-75 lbs) | #110 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated |
| Warranty | 5 | 3 |
| Enclosure | sealed | passive radiator |
| Output SPL at 12.5 Hz | 86.0 dB | - |
| Output SPL at 15 Hz | 91.5 dB | - |
| Output SPL at 20 Hz | 96.0 dB | - |
| Output SPL at 25 Hz | 101.0 dB | - |
| Output SPL at 31.5 Hz | 106.2 dB | - |
| Output SPL at 40 Hz | 112.6 dB | - |
| Output SPL at 50 Hz | 116.3 dB | - |
| Output SPL at 63 Hz | 119.4 dB | - |
| Output SPL at 80 Hz | 119.0 dB | - |
| Output SPL at 100 Hz | 119.3 dB | - |
| Output SPL at 125 Hz | 118.4 dB | - |
| CEA-2010-A Average (40-80Hz) | 116.8 dB | - |
| Dimensions | 14.6”H x 14.2”W x 16.1”D (370.1 x 359.9 x 410.0 mm) | 16.1”H x 19.2”W x 21.3”D (410 x 488 x 540 mm) |
| Weight | 59.5 lbs (27.0 kg) | 93.7 lbs (42.5 kg) |
| Cabinet Color | black, white | black, white |
| Country | Norway | United Kingdom |
| Measurement Source | Audioholics | - |
| Frequency Response | 23-250Hz, ±3dB | 19Hz (-6dB, manufacturer specified) |
| Amplifier Power | 500W RMS | 850W RMS (1,000W peak) |
| Drivers | 2x 10” (254mm) driver | 12” (305mm) driver, 12” passive radiator |
| Inputs | XLR (balanced, in plus through), RCA (stereo), speaker-level | - |
| 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 | - |
Related Speaker Comparisons
How Sigberg Audio 10D compares with other leading options:
- Monoprice SW-15 vs Sigberg Audio 10D
- SVS SB-3000 vs Sigberg Audio 10D
- Paradigm XR11 vs Sigberg Audio 10D
- Perlisten R210s vs Sigberg Audio 10D
- Bowers & Wilkins DB2D vs Sigberg Audio 10D
Prices on this page were last checked October 11, 2026 at 4:59 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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The Two Speakers In Full
Sigberg Audio 10D: $4,067.37 Sigberg Audio eBay
Pros: Dual 10-inch sealed with 500W RMS, 116.8dB average. Force-cancelling opposed drivers eliminate vibration. Scan-Speak driver linearity with 9-band parametric EQ. Built-in active limiter. Smallest dual-10 design worldwide.
Full Sigberg Audio 10D review and specifications →
| Released | Jan 2024 (2 years ago) |
|---|---|
| AES Input | No |
| Amplifier Power | 500W RMS |
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 116.8 dB |
| Cabinet Color | black, white |
| Coaxial Input | No |
| Country | Norway |
| Dimensions | 14.6”H x 14.2”W x 16.1”D (370.1 x 359.9 x 410.0 mm) |
| Drivers | 2x 10” (254mm) driver |
| Enclosure | sealed |
| Frequency Response | 23-250Hz, ±3dB |
| HDMI Input | No |
| Inputs | XLR (balanced, in plus through), RCA (stereo), speaker-level |
| Measurement Source | Audioholics |
| Optical Input | No |
| Output SPL at 12.5 Hz | 86.0 dB |
| Output SPL at 15 Hz | 91.5 dB |
| Output SPL at 20 Hz | 96.0 dB |
| Output SPL at 25 Hz | 101.0 dB |
| Output SPL at 31.5 Hz | 106.2 dB |
| Output SPL at 40 Hz | 112.6 dB |
| Output SPL at 50 Hz | 116.3 dB |
| Output SPL at 63 Hz | 119.4 dB |
| Output SPL at 80 Hz | 119.0 dB |
| Output SPL at 100 Hz | 119.3 dB |
| Output SPL at 125 Hz | 118.4 dB |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | No |
| Warranty | 5 |
| Weight | 59.5 lbs (27.0 kg) |
| XLR Input | Yes |
- 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
REL Acoustics S/850: $3,999.00 Estimated REL Acoustics eBay
Older model: the REL Acoustics R-528 (ranked higher, rated 3.7/5). See every REL S and Reference Series generation.
Same family: the REL Acoustics S/550 (smaller subwoofer, ranked lower, estimated 3.5/5), the REL Acoustics Carbon Special Black Label (larger subwoofer, estimated 3.9/5) and the REL Acoustics 212 Black Label (larger subwoofer, estimated 4.2/5).
Pros: Front-firing 12 inch carbon and aluminum driver plus a down-firing 12 inch passive radiator, driven by an 850W RMS Class D amplifier (1,000W peak). REL rates it at 19Hz at the -6dB point. High level Speakon, RCA and LFE RCA/XLR inputs, and REL’s Airship wireless option, make it easy to blend with stereo and theater systems.
Cons: No independent measurements yet, so its output can’t be compared with ranked subwoofers; the rating is estimated from the measured REL Acoustics R-528, an older 12 inch REL that averaged 112.8dB in the CEA-2010 bands but fell to 92.7dB at 25Hz. At 42.5 kg it is very heavy, and it costs far more than measured 12 inch subwoofers with more output.
Full REL Acoustics S/850 review and specifications →
| Released | Sep 2025 (1 year ago) |
|---|---|
| Amplifier Power | 850W RMS (1,000W peak) |
| Cabinet Color | black, white |
| Country | United Kingdom |
| Dimensions | 16.1”H x 19.2”W x 21.3”D (410 x 488 x 540 mm) |
| Drivers | 12” (305mm) driver, 12” passive radiator |
| Enclosure | passive radiator |
| Frequency Response | 19Hz (-6dB, manufacturer specified) |
| Warranty | 3 |
| Weight | 93.7 lbs (42.5 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons