JTR Speakers Captivator 4000ULF vs Monoprice Monolith M-215

Last updated: September 17, 2026

Short answer: the JTR Speakers Captivator 4000ULF for better sound quality, the Monoprice Monolith M-215 for the lower price. The JTR Speakers Captivator 4000ULF ranks #6 of 110 subwoofers, rated 4.5/5, at $5699. The Monoprice Monolith M-215 ranks #23, rated 4.4/5, at $2999.99, $2699.01 cheaper.

JTR Speakers Captivator 4000ULF vs Monoprice Monolith M-215

Buy the JTR Speakers Captivator 4000ULF if sound quality is the priority over the price, or the Monoprice Monolith M-215 if the price is the priority over sound quality.

Want more options? Browse the full Subwoofers rankings.

Buy the JTR Speakers Captivator 4000ULF at JTR Speakers ($5,699 each) →Buy the Monoprice Monolith M-215 at Monoprice ($2999.99) →

Specifications Side By Side

JTR Speakers Captivator 4000ULF Monoprice Monolith M-215
Price$5,000$2999.99
Ranked#6 of 110 in Large Home Subwoofers (Over 75 lbs)#23 of 110 in Large 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"H x 20.5"W x 39.5"D (1041.4 x 520.7 x 1003.3 mm)42.3"H x 20"W x 27.6"D (1074.4 x 508.0 x 701.0 mm)
Weight265 lbs (120.2 kg)216.1 lbs (98.0 kg)
Warranty5/35
Cabinet Colorblack, customblack
CountryUnited StatesUnited States
Measurement SourceData-bassBrent Butterworth
Drivers2x 18" (457mm) driver2x 15" (381mm) drivers
InputsXLR, RCA-
XLR InputYes-
RCA InputYes-
TRS InputNo-
Optical InputNo-
Coaxial InputNo-
USB InputNo-
HDMI InputNo-
AES InputNo-
Aux InputNo-
Buy the JTR Speakers Captivator 4000ULF at JTR Speakers ($5,699 each) →Buy the Monoprice Monolith M-215 at Monoprice ($2999.99) →

More worthwhile head-to-heads for JTR Speakers Captivator 4000ULF:

Prices on this page were last checked September 23, 2026 at 11:24 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

JTR Speakers Captivator 4000ULF: $5,000 JTR Speakers eBay

JTR Speakers Captivator 4000ULF ranking card

Pros: Independent CEA-2010 testing records 122.3 dB at 20 Hz and 130.8 dB through 40-80 Hz. The ported, front enclosure with 2x 18” (457mm) driver has the headroom for demanding film bass in a large room.

Cons: The 1041.4H x 520.7W x 1003.3D mm cabinet and 120.2 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Full JTR Speakers Captivator 4000ULF review and specifications →

AES InputNo
Aux InputNo
CEA-2010-A Average (40-80Hz)130.8 dB
Cabinet Colorblack, custom
Coaxial InputNo
CountryUnited States
Dimensions41"H x 20.5"W x 39.5"D (1041.4 x 520.7 x 1003.3 mm)
Drivers2x 18" (457mm) driver
Enclosureported, front
HDMI InputNo
InputsXLR, RCA
Measurement SourceData-bass
Optical InputNo
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
RCA InputYes
TRS InputNo
USB InputNo
Warranty5/3
Weight265 lbs (120.2 kg)
XLR InputYes
Check current price at JTR Speakers ($5,699 each) →Search eBay for JTR Speakers Captivator 4000ULF →

Monoprice Monolith M-215: $2999.99 Monoprice eBay

Monoprice Monolith M-215 ranking card

Pros: Independent CEA-2010 testing records 118.9 dB at 20 Hz and 125.9 dB through 40-80 Hz. The ported, front enclosure with 2x 15” (381mm) drivers has the headroom for demanding film bass in a large room.

Cons: The 1074.4H x 508.0W x 701.0D mm cabinet and 98.0 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Notes: Product # 38543

Full Monoprice Monolith M-215 review and specifications →

CEA-2010-A Average (40-80Hz)125.9 dB
Cabinet Colorblack
CountryUnited States
Dimensions42.3"H x 20"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)
Check current price at Monoprice ($2999.99) →Search eBay for Monoprice Monolith M-215 →