Monoprice Monolith M-15 V2 vs Rythmik F18

Last updated: August 9, 2026

Short answer: the Monoprice Monolith M-15 V2. It ranks #55 of 97 subwoofers at $1500; the Rythmik F18 ranks #60 and costs $1850, so there is not much of a tradeoff to weigh.

Buy the Monoprice Monolith M-15 V2 if the ranking matters more than the price. Buy the Rythmik F18 if the price matters more than the ranking.

Specifications Side By Side

Monoprice Monolith M-15 V2 Rythmik F18
Price$1,500$1,850
Ranked#55 of 97 in Large Powered Home Subwoofers (Over 75 lbs)#60 of 97 in Large Powered Home Subwoofers (Over 75 lbs)
Enclosureported, frontsealed
Output SPL at 12.5 Hz91.0 dB97.4 dB
Output SPL at 15 Hz106.3 dB102.0 dB
Output SPL at 20 Hz112.6 dB106.2 dB
Output SPL at 25 Hz116.6 dB110.9 dB
Output SPL at 31.5 Hz119.5 dB114.3 dB
Output SPL at 40 Hz120.9 dB117.1 dB
Output SPL at 50 Hz120.6 dB119.1 dB
Output SPL at 63 Hz120.0 dB120.5 dB
Output SPL at 80 Hz118.7 dB121.2 dB
Output SPL at 100 Hz120.1 dB121.4 dB
Output SPL at 125 Hz120.2 dB121.4 dB
CEA-2010-A Average (40-80Hz)120.0 dB119.5 dB
Dimensions28.7"H x 17.7"W x 26.8"D (729.0 x 449.6 x 680.7 mm)20.5"H x 20.5"W x 21.0"D (520.7 x 520.7 x 533.4 mm)
Weight132.9 lbs / 60.3 kg115.1 lbs / 52.2 kg
Warranty55/3
Cabinet Colorblackblack
CountryUnited StatesUnited States
Measurement SourceManufacturerData-bass
Drivers15" (381mm) driver18" (457mm) driver
Output SPL at 10 Hz-93.7 dB

The Two Speakers In Full

Monoprice Monolith M-15 V2: $1,500 Amazon

Monoprice Monolith M-15 V2 ranking card

Notes: Product # 42851

CEA-2010-A Average (40-80Hz)120.0 dB
Cabinet Colorblack
CountryUnited States
Dimensions28.7"H x 17.7"W x 26.8"D (729.0 x 449.6 x 680.7 mm)
Drivers15" (381mm) driver
Enclosureported, front
Measurement SourceManufacturer
Output SPL at 12.5 Hz91.0 dB
Output SPL at 15 Hz106.3 dB
Output SPL at 20 Hz112.6 dB
Output SPL at 25 Hz116.6 dB
Output SPL at 31.5 Hz119.5 dB
Output SPL at 40 Hz120.9 dB
Output SPL at 50 Hz120.6 dB
Output SPL at 63 Hz120.0 dB
Output SPL at 80 Hz118.7 dB
Output SPL at 100 Hz120.1 dB
Output SPL at 125 Hz120.2 dB
Warranty5
Weight132.9 lbs / 60.3 kg
Check current price at Amazon ($1,500) →

Rythmik F18: $1,850

Rythmik F18 ranking card

CEA-2010-A Average (40-80Hz)119.5 dB
Cabinet Colorblack
CountryUnited States
Dimensions20.5"H x 20.5"W x 21.0"D (520.7 x 520.7 x 533.4 mm)
Drivers18" (457mm) driver
Enclosuresealed
Measurement SourceData-bass
Output SPL at 10 Hz93.7 dB
Output SPL at 12.5 Hz97.4 dB
Output SPL at 15 Hz102.0 dB
Output SPL at 20 Hz106.2 dB
Output SPL at 25 Hz110.9 dB
Output SPL at 31.5 Hz114.3 dB
Output SPL at 40 Hz117.1 dB
Output SPL at 50 Hz119.1 dB
Output SPL at 63 Hz120.5 dB
Output SPL at 80 Hz121.2 dB
Output SPL at 100 Hz121.4 dB
Output SPL at 125 Hz121.4 dB
Warranty5/3
Weight115.1 lbs / 52.2 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.