JTR Speakers Captivator 4000ULF vs Monoprice Monolith M-215

Last updated: August 9, 2026

Short answer: the JTR Speakers Captivator 4000ULF for the higher ranking, the Monoprice Monolith M-215 for the lower price. The JTR Speakers Captivator 4000ULF ranks #4 of 97 subwoofers at $5000. The Monoprice Monolith M-215 ranks #18 at $2500, $2500 cheaper.

Buy the JTR Speakers Captivator 4000ULF if the ranking matters more than the price. Buy the Monoprice Monolith M-215 if the price matters more than the ranking.

Specifications Side By Side

JTR Speakers Captivator 4000ULF Monoprice Monolith M-215
Price$5,000$2,500
Ranked#4 of 97 in Large Powered Home Subwoofers (Over 75 lbs)#18 of 97 in Large Powered Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, front
Output SPL at 10 Hz111.0 dB-
Output SPL at 12.5 Hz115.3 dB103.9 dB
Output SPL at 15 Hz119.3 dB113.1 dB
Output SPL at 20 Hz122.3 dB118.9 dB
Output SPL at 25 Hz126.1 dB122.6 dB
Output SPL at 31.5 Hz129.3 dB125.2 dB
Output SPL at 40 Hz130.7 dB126.4 dB
Output SPL at 50 Hz131.2 dB126.1 dB
Output SPL at 63 Hz130.9 dB125.6 dB
Output SPL at 80 Hz130.6 dB125.6 dB
Output SPL at 100 Hz130.5 dB125.7 dB
Output SPL at 125 Hz129.5 dB126.3 dB
CEA-2010-A Average (40-80Hz)130.8 dB125.9 dB
Dimensions41.0"H x 20.5"W x 39.5"D (1041.4 x 520.7 x 1003.3 mm)42.3"H x 20.0"W x 27.6"D (1074.4 x 508.0 x 701.0 mm)
Weight265 lbs / 120.2 kg216.1 lbs / 98.0 kg
Warranty5/35
Cabinet Colorblack, customblack
CountryUnited StatesUnited States
Measurement SourceData-bassBrent Butterworth
Drivers2x 18" (457mm) driver2x 15" (381mm) drivers

The Two Speakers In Full

JTR Speakers Captivator 4000ULF: $5,000

JTR Speakers Captivator 4000ULF ranking card

CEA-2010-A Average (40-80Hz)130.8 dB
Cabinet Colorblack, custom
CountryUnited States
Dimensions41.0"H x 20.5"W x 39.5"D (1041.4 x 520.7 x 1003.3 mm)
Drivers2x 18" (457mm) driver
Enclosureported, front
Measurement SourceData-bass
Output SPL at 10 Hz111.0 dB
Output SPL at 12.5 Hz115.3 dB
Output SPL at 15 Hz119.3 dB
Output SPL at 20 Hz122.3 dB
Output SPL at 25 Hz126.1 dB
Output SPL at 31.5 Hz129.3 dB
Output SPL at 40 Hz130.7 dB
Output SPL at 50 Hz131.2 dB
Output SPL at 63 Hz130.9 dB
Output SPL at 80 Hz130.6 dB
Output SPL at 100 Hz130.5 dB
Output SPL at 125 Hz129.5 dB
Warranty5/3
Weight265 lbs / 120.2 kg

Monoprice Monolith M-215: $2,500

Monoprice Monolith M-215 ranking card

Notes: Product # 38543

CEA-2010-A Average (40-80Hz)125.9 dB
Cabinet Colorblack
CountryUnited States
Dimensions42.3"H x 20.0"W x 27.6"D (1074.4 x 508.0 x 701.0 mm)
Drivers2x 15" (381mm) drivers
Enclosureported, front
Measurement SourceBrent Butterworth
Output SPL at 12.5 Hz103.9 dB
Output SPL at 15 Hz113.1 dB
Output SPL at 20 Hz118.9 dB
Output SPL at 25 Hz122.6 dB
Output SPL at 31.5 Hz125.2 dB
Output SPL at 40 Hz126.4 dB
Output SPL at 50 Hz126.1 dB
Output SPL at 63 Hz125.6 dB
Output SPL at 80 Hz125.6 dB
Output SPL at 100 Hz125.7 dB
Output SPL at 125 Hz126.3 dB
Warranty5
Weight216.1 lbs / 98.0 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.