Short answer: the Sigberg Audio INKOGNITO 12. It ranks #64 of 212 subwoofers by sound quality, rated 3.8/5, at $3,456.29. The REL Acoustics S/550 ranks #155, rated 3.5/5, at $3,299, $157.29 cheaper, which does not close the gap in sound quality.
What the Sigberg Audio INKOGNITO 12 does well: Ultra-slim 12-inch sealed design (6.69” depth) with 250W RMS reaches 23Hz.
Why pick the REL Acoustics S/550: The smallest model in REL’s 2025 Serie S, replacing the S/510: a 10” CarbonAlloy active driver and a 12” down-firing passive radiator driven by a 550W Linear Class D amplifier, reaching 19Hz (-6dB). Watch for: No independent measurements yet, so its output can’t be compared directly with ranked subwoofers; the rating is estimated from the measured REL Acoustics R-528 (112.8dB in three of the four 40 to 80Hz CEA-2010 bands) and its sibling REL Acoustics S/850.
Buy the Sigberg Audio INKOGNITO 12. It is rated higher for sound quality, and the $157.29 you would save on the REL Acoustics S/550 does not close the gap.
Worth knowing: the REL Acoustics S/550 has not been measured yet. Its rating is estimated from related models, with a likely range of 3.1 to 3.7, so treat this verdict as provisional.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Sigberg Audio INKOGNITO 12 | REL Acoustics S/550 | |
|---|---|---|
| Price | $3,456.29 | $3,299.00 |
| Ranked | #64 of 212 in Medium Home Subwoofers (30-75 lbs) | #155 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated |
| Warranty | 5 | 3 |
| Enclosure | sealed | passive radiator |
| Output SPL at 20 Hz | 92.0 dB | - |
| Output SPL at 25 Hz | 98.0 dB | - |
| Output SPL at 31.5 Hz | 104.0 dB | - |
| Output SPL at 40 Hz | 112.5 dB | - |
| Output SPL at 50 Hz | 114.0 dB | - |
| Output SPL at 63 Hz | 115.0 dB | - |
| Output SPL at 80 Hz | 116.0 dB | - |
| CEA-2010-A Average (40-80Hz) | 114.4 dB | - |
| Dimensions | 21.3”H x 25.6”W x 6.7”D (539.8 x 650.0 x 169.9 mm) | 16.1”H x 15.7”W x 18.3”D (410 x 400 x 464 mm) |
| Weight | 48.5 lbs (22.0 kg) | 69.9 lbs (31.7 kg) |
| Cabinet Color | black, white | - |
| Country | Norway | United Kingdom |
| Measurement Source | Manufacturer | - |
| Frequency Response | 23-250Hz, ±3dB | 19Hz -6dB (manufacturer specified) |
| Amplifier Power | 250W RMS | 550W Linear Class D |
| Drivers | 12” (305mm) driver | 10” CarbonAlloy driver, 12” down-firing passive radiator |
| Inputs | XLR (balanced, in plus through), RCA, speaker-level, USB (config only) | - |
| XLR Input | Yes | - |
| RCA Input | Yes | - |
| TRS Input | No | - |
| Optical Input | No | - |
| Coaxial Input | No | - |
| USB Input | Yes | - |
| HDMI Input | No | - |
| AES Input | No | - |
| Aux Input | No | - |
Related Speaker Comparisons
More top alternatives to Sigberg Audio INKOGNITO 12:
- Monoprice SW-15 vs Sigberg Audio INKOGNITO 12
- SVS SB-3000 vs Sigberg Audio INKOGNITO 12
- Bowers & Wilkins DB4S vs Sigberg Audio INKOGNITO 12
- Sigberg Audio INKOGNITO 12 vs REL Acoustics S/850
- Sigberg Audio INKOGNITO 12 vs Sigberg Audio INKOGNITO 10
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 INKOGNITO 12: $3,456.29 Sigberg Audio eBay
Same family: the Sigberg Audio INKOGNITO 10 (smaller subwoofer, ranked lower, rated 3.4/5).
Pros: Ultra-slim 12-inch sealed design (6.69” depth) with 250W RMS reaches 23Hz. Real quality accurate bass with minimal distortion and 10-band parametric EQ. Wall-mountable or under-furniture placement without sound loss. Premium European build quality.
Notes: low profile (<8in)
Full Sigberg Audio INKOGNITO 12 review and specifications →
| AES Input | No |
|---|---|
| Amplifier Power | 250W RMS |
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 114.4 dB |
| Cabinet Color | black, white |
| Coaxial Input | No |
| Country | Norway |
| Dimensions | 21.3”H x 25.6”W x 6.7”D (539.8 x 650.0 x 169.9 mm) |
| Drivers | 12” (305mm) driver |
| Enclosure | sealed |
| Frequency Response | 23-250Hz, ±3dB |
| HDMI Input | No |
| Inputs | XLR (balanced, in plus through), RCA, speaker-level, USB (config only) |
| Measurement Source | Manufacturer |
| Optical Input | No |
| Output SPL at 20 Hz | 92.0 dB |
| Output SPL at 25 Hz | 98.0 dB |
| Output SPL at 31.5 Hz | 104.0 dB |
| Output SPL at 40 Hz | 112.5 dB |
| Output SPL at 50 Hz | 114.0 dB |
| Output SPL at 63 Hz | 115.0 dB |
| Output SPL at 80 Hz | 116.0 dB |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | Yes |
| Warranty | 5 |
| Weight | 48.5 lbs (22.0 kg) |
| XLR Input | Yes |
- Links
- Reviews, Comparisons and Sound Samples
- These figures are manufacturer-specified rather than independently measured.
- Head-to-Head Comparisons
REL Acoustics S/550: $3,299.00 Estimated Audio Advice eBay
Same family: the REL Acoustics S/850 (larger subwoofer, ranked higher, estimated 3.7/5), 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). See every REL S and Reference Series generation.
Pros: The smallest model in REL’s 2025 Serie S, replacing the S/510: a 10” CarbonAlloy active driver and a 12” down-firing passive radiator driven by a 550W Linear Class D amplifier, reaching 19Hz (-6dB). It includes REL’s high-level speaker connection for integrating with stereo amplifiers.
Cons: No independent measurements yet, so its output can’t be compared directly with ranked subwoofers; the rating is estimated from the measured REL Acoustics R-528 (112.8dB in three of the four 40 to 80Hz CEA-2010 bands) and its sibling REL Acoustics S/850. It is placed below the larger REL Acoustics S/850, and at 31.7kg it is heavy for a 10” sub.
Full REL Acoustics S/550 review and specifications →
| Released | Oct 2025 (1 year ago) |
|---|---|
| Amplifier Power | 550W Linear Class D |
| Country | United Kingdom |
| Dimensions | 16.1”H x 15.7”W x 18.3”D (410 x 400 x 464 mm) |
| Drivers | 10” CarbonAlloy driver, 12” down-firing passive radiator |
| Enclosure | passive radiator |
| Frequency Response | 19Hz -6dB (manufacturer specified) |
| Warranty | 3 |
| Weight | 69.9 lbs (31.7 kg) |
- 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