JTR Speakers Captivator S2 vs Monoprice Monolith 16 THX Ultra

Last updated: August 9, 2026

Short answer: the JTR Speakers Captivator S2 for the higher ranking, the Monoprice Monolith 16 THX Ultra for the lower price. The JTR Speakers Captivator S2 ranks #7 of 97 subwoofers at $3995. The Monoprice Monolith 16 THX Ultra ranks #13 at $2300, $1695 cheaper.

The case for the Monoprice Monolith 16 THX Ultra: 16-inch ported driver and THX Ultra certification deliver 126.5dB CEA-2010-A average at a fraction of the price of the subwoofers ranked. The tradeoff: Heavy at 78 kg and ported design can interact with room acoustics.

Buy the JTR Speakers Captivator S2 if the ranking matters more than the price. Buy the Monoprice Monolith 16 THX Ultra if the price matters more than the ranking.

Specifications Side By Side

JTR Speakers Captivator S2 Monoprice Monolith 16 THX Ultra
Price$3995$2,300
Ranked#7 of 97 in Large Powered Home Subwoofers (Over 75 lbs)#13 of 97 in Large Powered Home Subwoofers (Over 75 lbs)
Enclosuresealedported, front
Output SPL at 10 Hz100.3 dB-
Output SPL at 12.5 Hz103.3 dB-
Output SPL at 15 Hz108.7 dB107.3 dB
Output SPL at 20 Hz115.1 dB118.4 dB
Output SPL at 25 Hz119.7 dB123.3 dB
Output SPL at 31.5 Hz124.8 dB125.1 dB
Output SPL at 40 Hz129.3 dB126.3 dB
Output SPL at 50 Hz130.3 dB126.5 dB
Output SPL at 63 Hz129.4 dB126.6 dB
Output SPL at 80 Hz128.5 dB126.8 dB
Output SPL at 100 Hz128.1 dB127.2 dB
Output SPL at 125 Hz128.0 dB127.6 dB
CEA-2010-A Average (40-80Hz)129.4 dB126.5 dB
Dimensions40.0"H x 21.0"W x 18.0"D (1016.0 x 533.4 x 457.2 mm)25.6"H x 22.0"W x 28.1"D (650.2 x 558.8 x 713.7 mm)
Weight220 lbs / 99.8 kg171.5 lbs / 77.8 kg
Warranty5/35
CountryUnited StatesUnited States
Measurement SourceData-bassAudioholics
Drivers2x 18" (457mm) drivers16" (406mm) driver
Cabinet Color-black

The Two Speakers In Full

JTR Speakers Captivator S2: $3995

JTR Speakers Captivator S2 ranking card

Notes: Replaced by “RS2”

CEA-2010-A Average (40-80Hz)129.4 dB
CountryUnited States
Dimensions40.0"H x 21.0"W x 18.0"D (1016.0 x 533.4 x 457.2 mm)
Drivers2x 18" (457mm) drivers
Enclosuresealed
Measurement SourceData-bass
Output SPL at 10 Hz100.3 dB
Output SPL at 12.5 Hz103.3 dB
Output SPL at 15 Hz108.7 dB
Output SPL at 20 Hz115.1 dB
Output SPL at 25 Hz119.7 dB
Output SPL at 31.5 Hz124.8 dB
Output SPL at 40 Hz129.3 dB
Output SPL at 50 Hz130.3 dB
Output SPL at 63 Hz129.4 dB
Output SPL at 80 Hz128.5 dB
Output SPL at 100 Hz128.1 dB
Output SPL at 125 Hz128.0 dB
Warranty5/3
Weight220 lbs / 99.8 kg

Monoprice Monolith 16 THX Ultra: $2,300

Monoprice Monolith 16 THX Ultra ranking card

Pros: 16-inch ported driver and THX Ultra certification deliver 126.5dB CEA-2010-A average at a fraction of the price of the subwoofers ranked above it.

Cons: Heavy at 78 kg and ported design can interact with room acoustics.

Notes: Product # 42031

CEA-2010-A Average (40-80Hz)126.5 dB
Cabinet Colorblack
CountryUnited States
Dimensions25.6"H x 22.0"W x 28.1"D (650.2 x 558.8 x 713.7 mm)
Drivers16" (406mm) driver
Enclosureported, front
Measurement SourceAudioholics
Output SPL at 15 Hz107.3 dB
Output SPL at 20 Hz118.4 dB
Output SPL at 25 Hz123.3 dB
Output SPL at 31.5 Hz125.1 dB
Output SPL at 40 Hz126.3 dB
Output SPL at 50 Hz126.5 dB
Output SPL at 63 Hz126.6 dB
Output SPL at 80 Hz126.8 dB
Output SPL at 100 Hz127.2 dB
Output SPL at 125 Hz127.6 dB
Warranty5
Weight171.5 lbs / 77.8 kg

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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.