Short answer: the Paradigm XR11. It ranks #22 of 212 subwoofers by sound quality, rated 4.1/5, at $3,999.99; the REL Acoustics S/850 ranks #110, rated 3.7/5, at $3,999. The price gap is small enough that the sound-quality ranking should decide it.
The Paradigm XR11 is the better-sounding pick. 11-inch ultra-high-excursion CARBON-X driver with ART surround in an ultra-rigid sealed cabinet, driven by an immense 1,100W RMS / 2,200W peak Class D amplifier. The catch: High investment cost.
What the REL Acoustics S/850 does well: 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 catch: 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 Paradigm XR11. It is rated higher for sound quality, and saving $0.99 with the REL Acoustics S/850 does not make up for the sound-quality gap.
About the ratings: neither speaker has been measured yet, so both ratings are estimated from measured siblings and predecessors (likely ranges: Paradigm XR11 3.9 to 4.3; REL Acoustics S/850 3.4 to 4.0). Treat this verdict as provisional.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| Paradigm XR11 | REL Acoustics S/850 | |
|---|---|---|
| Price | $3,999.99 | $3,999.00 |
| Ranked | #22 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated | #110 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated |
| Country | Canada | United Kingdom |
| Warranty | 3 | 3 |
| Enclosure | sealed | passive radiator |
| Drivers | 11” (279mm) ultra-high-excursion CARBON-X unibody driver with ART surround | 12” (305mm) driver, 12” passive radiator |
| Amplifier Power | 1,100W RMS / 2,200W dynamic peak (Class D) | 850W RMS (1,000W peak) |
| Frequency Response | 20Hz - 140Hz (+/- 3dB, manufacturer specified) | 19Hz (-6dB, manufacturer specified) |
| Dimensions | 16.2”H x 15.3”W x 16.9”D (412 x 388 x 429 mm) | 16.1”H x 19.2”W x 21.3”D (410 x 488 x 540 mm) |
| Weight | 63.9 lbs (29.0 kg) | 93.7 lbs (42.5 kg) |
| Cabinet Color | - | black, white |
Related Speaker Comparisons
More worthwhile head-to-heads for Paradigm XR11:
- Paradigm XR11 vs Perlisten R210s
- Paradigm XR11 vs Sigberg Audio 10D
- Paradigm XR11 vs Bowers & Wilkins DB2D
- Sigberg Audio 10D vs REL Acoustics S/850
- Sigberg Audio INKOGNITO 12 vs REL Acoustics S/850
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
Paradigm XR11: $3,999.99 Estimated Paradigm eBay
Same family: the Paradigm XR13 (larger subwoofer, estimated 4.3/5).
Pros: 11-inch ultra-high-excursion CARBON-X driver with ART surround in an ultra-rigid sealed cabinet, driven by an immense 1,100W RMS / 2,200W peak Class D amplifier. Advanced Anthem Room Correction (ARC Genesis) delivers clean reference bass down to 20Hz.
Cons: High investment cost. Sealed alignment trades ultimate 16Hz output headroom compared to larger 13-inch and 15-inch flagship subwoofers.
Full Paradigm XR11 review and specifications →
| Released | 2023 (3 years ago) |
|---|---|
| Amplifier Power | 1,100W RMS / 2,200W dynamic peak (Class D) |
| Country | Canada |
| Dimensions | 16.2”H x 15.3”W x 16.9”D (412 x 388 x 429 mm) |
| Drivers | 11” (279mm) ultra-high-excursion CARBON-X unibody driver with ART surround |
| Enclosure | sealed |
| Frequency Response | 20Hz - 140Hz (+/- 3dB, manufacturer specified) |
| Warranty | 3 |
| Weight | 63.9 lbs (29.0 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
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