Short answer: the Outlaw Audio Ultra-X13. It ranks #70 of 97 subwoofers by sound quality at $1299; the REL Acoustics HT/1510 Predator II ranks #71 and costs $2526.62, so there is not much of a tradeoff to weigh.
What the REL Acoustics HT/1510 Predator II offers: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 118.1 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music. Watch for: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 457.2H x 541.0W x 492.8D mm cabinet and 45.2 kg mass still require deliberate placement and calibration.
What the Outlaw Audio Ultra-X13 offers: Independent CEA-2010 testing records 109.8 dB at 20 Hz and 118.1 dB through 40-80 Hz. The ported, bottom enclosure with 13” (330mm) driver has the headroom for demanding film bass in a large room. Watch for: The 635.0H x 457.2W x 584.2D mm cabinet and 47.6 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Buy the Outlaw Audio Ultra-X13. It ranks higher for sound quality than the REL Acoustics HT/1510 Predator II and costs less, so the other one has nothing left to offer.
Specifications Side By Side
| REL Acoustics HT/1510 Predator II | Outlaw Audio Ultra-X13 | |
|---|---|---|
| Price | $2,526.62 | $1299 Discontinued |
| Ranked | #71 of 97 in Large Powered Home Subwoofers (Over 75 lbs) | #70 of 97 in Large Powered Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, bottom |
| Output SPL at 15 Hz | 91.4 dB | 101.1 dB |
| Output SPL at 20 Hz | 98.0 dB | 109.8 dB |
| Output SPL at 25 Hz | 104.4 dB | 114.1 dB |
| Output SPL at 31.5 Hz | 111.1 dB | 117.1 dB |
| Output SPL at 40 Hz | 116.9 dB | 118.2 dB |
| Output SPL at 50 Hz | 118.5 dB | 118.0 dB |
| Output SPL at 63 Hz | 118.5 dB | 118.1 dB |
| Output SPL at 80 Hz | 118.4 dB | 118.1 dB |
| Output SPL at 100 Hz | 118.5 dB | 118.0 dB |
| Output SPL at 125 Hz | 118.0 dB | 117.6 dB |
| CEA-2010-A Average (40-80Hz) | 118.1 dB | 118.1 dB |
| Dimensions | 18"H x 21.3"W x 19.4"D (457.2 x 541.0 x 492.8 mm) | 25"H x 18"W x 23"D (635.0 x 457.2 x 584.2 mm) |
| Weight | 99.6 lbs / 45.2 kg | 104.9 lbs / 47.6 kg |
| Warranty | 3 | 3 |
| Cabinet Color | black | - |
| Country | United Kingdom | United States |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 15" (381mm) driver | 13" (330mm) driver |
| Discontinued | - | Yes |
Related Speaker Comparisons
A few more comparisons worth a look in the same class:
- Genelec 7071A vs SVS PB12-Plus
- Velodyne Acoustics DD-15+ vs Velodyne Acoustics DD-18+
- Harbottle Audio C18 L1 vs Velodyne Acoustics DD-18+
- SVS PB12-Plus vs REL Acoustics HT/1510 Predator II
- HSU Research VTF-15H vs SVS SB-3000
Prices on this page were last checked September 8, 2026 at 6:02 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
REL Acoustics HT/1510 Predator II: $2,526.62 eBay
Pros: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 118.1 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music.
Cons: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 457.2H x 541.0W x 492.8D mm cabinet and 45.2 kg mass still require deliberate placement and calibration.
Full REL Acoustics HT/1510 Predator II review and specifications →
| CEA-2010-A Average (40-80Hz) | 118.1 dB |
|---|---|
| Cabinet Color | black |
| Country | United Kingdom |
| Dimensions | 18"H x 21.3"W x 19.4"D (457.2 x 541.0 x 492.8 mm) |
| Drivers | 15" (381mm) driver |
| Enclosure | sealed |
| Measurement Source | Audioholics |
| Output SPL at 15 Hz | 91.4 dB |
| Output SPL at 20 Hz | 98.0 dB |
| Output SPL at 25 Hz | 104.4 dB |
| Output SPL at 31.5 Hz | 111.1 dB |
| Output SPL at 40 Hz | 116.9 dB |
| Output SPL at 50 Hz | 118.5 dB |
| Output SPL at 63 Hz | 118.5 dB |
| Output SPL at 80 Hz | 118.4 dB |
| Output SPL at 100 Hz | 118.5 dB |
| Output SPL at 125 Hz | 118.0 dB |
| Warranty | 3 |
| Weight | 99.6 lbs / 45.2 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Outlaw Audio Ultra-X13: $1299 Discontinued eBay
Pros: Independent CEA-2010 testing records 109.8 dB at 20 Hz and 118.1 dB through 40-80 Hz. The ported, bottom enclosure with 13” (330mm) driver has the headroom for demanding film bass in a large room.
Cons: The 635.0H x 457.2W x 584.2D mm cabinet and 47.6 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential. Discontinued.
Full Outlaw Audio Ultra-X13 review and specifications →
| CEA-2010-A Average (40-80Hz) | 118.1 dB |
|---|---|
| Country | United States |
| Dimensions | 25"H x 18"W x 23"D (635.0 x 457.2 x 584.2 mm) |
| Discontinued | Yes |
| Drivers | 13" (330mm) driver |
| Enclosure | ported, bottom |
| Measurement Source | Audioholics |
| Output SPL at 15 Hz | 101.1 dB |
| Output SPL at 20 Hz | 109.8 dB |
| Output SPL at 25 Hz | 114.1 dB |
| Output SPL at 31.5 Hz | 117.1 dB |
| Output SPL at 40 Hz | 118.2 dB |
| Output SPL at 50 Hz | 118.0 dB |
| Output SPL at 63 Hz | 118.1 dB |
| Output SPL at 80 Hz | 118.1 dB |
| Output SPL at 100 Hz | 118.0 dB |
| Output SPL at 125 Hz | 117.6 dB |
| Warranty | 3 |
| Weight | 104.9 lbs / 47.6 kg |
- Links
- Reviews, Comparisons and Sound Samples