Short answer: the JTR Speakers Captivator S2 for the higher ranking, the Monoprice Monolith M15-S for the lower price. The JTR Speakers Captivator S2 ranks #7 of 97 subwoofers at $3995. The Monoprice Monolith M15-S ranks #62 at $999, $2996 cheaper.
Buy the JTR Speakers Captivator S2 if the ranking matters more than the price. Buy the Monoprice Monolith M15-S if the price matters more than the ranking.
Specifications Side By Side
| JTR Speakers Captivator S2 | Monoprice Monolith M15-S | |
|---|---|---|
| Price | $3995 | $999 |
| Ranked | #7 of 97 in Large Powered Home Subwoofers (Over 75 lbs) | #62 of 97 in Large Powered Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | sealed |
| Output SPL at 10 Hz | 100.3 dB | - |
| Output SPL at 12.5 Hz | 103.3 dB | - |
| Output SPL at 15 Hz | 108.7 dB | 100.1 dB |
| Output SPL at 20 Hz | 115.1 dB | 105.6 dB |
| Output SPL at 25 Hz | 119.7 dB | 111.2 dB |
| Output SPL at 31.5 Hz | 124.8 dB | 115.2 dB |
| Output SPL at 40 Hz | 129.3 dB | 118.4 dB |
| Output SPL at 50 Hz | 130.3 dB | 119.3 dB |
| Output SPL at 63 Hz | 129.4 dB | 119.6 dB |
| Output SPL at 80 Hz | 128.5 dB | 118.9 dB |
| Output SPL at 100 Hz | 128.1 dB | 119.1 dB |
| Output SPL at 125 Hz | 128.0 dB | 118.9 dB |
| CEA-2010-A Average (40-80Hz) | 129.4 dB | 119.0 dB |
| Dimensions | 40.0"H x 21.0"W x 18.0"D (1016.0 x 533.4 x 457.2 mm) | 23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm) |
| Weight | 220 lbs / 99.8 kg | 80 lbs / 36.3 kg |
| Warranty | 5/3 | 5 |
| Country | United States | United States |
| Measurement Source | Data-bass | Manufacturer |
| Drivers | 2x 18" (457mm) drivers | 15" (381mm) driver |
The Two Speakers In Full
JTR Speakers Captivator S2: $3995
Notes: Replaced by “RS2”
| CEA-2010-A Average (40-80Hz) | 129.4 dB |
|---|---|
| Country | United States |
| Dimensions | 40.0"H x 21.0"W x 18.0"D (1016.0 x 533.4 x 457.2 mm) |
| Drivers | 2x 18" (457mm) drivers |
| Enclosure | sealed |
| Measurement Source | Data-bass |
| Output SPL at 10 Hz | 100.3 dB |
| Output SPL at 12.5 Hz | 103.3 dB |
| Output SPL at 15 Hz | 108.7 dB |
| Output SPL at 20 Hz | 115.1 dB |
| Output SPL at 25 Hz | 119.7 dB |
| Output SPL at 31.5 Hz | 124.8 dB |
| Output SPL at 40 Hz | 129.3 dB |
| Output SPL at 50 Hz | 130.3 dB |
| Output SPL at 63 Hz | 129.4 dB |
| Output SPL at 80 Hz | 128.5 dB |
| Output SPL at 100 Hz | 128.1 dB |
| Output SPL at 125 Hz | 128.0 dB |
| Warranty | 5/3 |
| Weight | 220 lbs / 99.8 kg |
- Head-to-Head Comparisons
- JTR Speakers Captivator S2 vs Power Sound Audio (PSA) T18
- JTR Speakers Captivator S2 vs Power Sound Audio (PSA) V3600I
- JTR Speakers Captivator S2 vs Funk Audio Ultra 24.0
- JTR Speakers Captivator S2 vs JTR Speakers Captivator 215PRO
- JTR Speakers Captivator S2 vs JTR Speakers Captivator 4000ULF
- JTR Speakers Captivator S2 vs Power Sound Audio (PSA) TRIAX
- JTR Speakers Captivator S2 vs JTR Speakers Orbit Shifter LFU
- JTR Speakers Captivator S2 vs JTR Speakers Orbit Shifter PRO
- See all 17 comparisons
- Links
Monoprice Monolith M15-S: $999
Notes: Product # 35141
| CEA-2010-A Average (40-80Hz) | 119.0 dB |
|---|---|
| Country | United States |
| Dimensions | 23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm) |
| Drivers | 15" (381mm) driver |
| Enclosure | sealed |
| Measurement Source | Manufacturer |
| Output SPL at 15 Hz | 100.1 dB |
| Output SPL at 20 Hz | 105.6 dB |
| Output SPL at 25 Hz | 111.2 dB |
| Output SPL at 31.5 Hz | 115.2 dB |
| Output SPL at 40 Hz | 118.4 dB |
| Output SPL at 50 Hz | 119.3 dB |
| Output SPL at 63 Hz | 119.6 dB |
| Output SPL at 80 Hz | 118.9 dB |
| Output SPL at 100 Hz | 119.1 dB |
| Output SPL at 125 Hz | 118.9 dB |
| Warranty | 5 |
| Weight | 80 lbs / 36.3 kg |
- Head-to-Head Comparisons
- Monoprice Monolith M15-S vs Rythmik F18
- Monoprice Monolith M15-S vs Monoprice Monolith M-15 V2
- Monoprice Monolith M15-S vs SVS PB-4000
- Monoprice Monolith M15-S vs HSU Research VTF-3 MK5 HP
- Monoprice Monolith M15-S vs HSU Research VTF-15H MK2
- Monoprice Monolith M15-S vs Rythmik FV15HP
- Monoprice Monolith M15-S vs Monoprice Monolith M-215
- Monoprice Monolith M15-S vs Reaction Audio PV-15X
- See all 15 comparisons
- Links
As an Amazon Associate I earn from qualifying purchases.
Product prices and availability were last checked August 9, 2026 at 6:57 AM UTC 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.

