Monoprice Monolith M15-S vs Rythmik FV15HP

Last updated: September 17, 2026

Short answer: the Rythmik FV15HP for better sound quality, the Monoprice Monolith M15-S for the lower price. The Rythmik FV15HP ranks #48 of 110 subwoofers, rated 4.2/5, at $2127. The Monoprice Monolith M15-S ranks #72, rated 4.1/5, at $999, $1128 cheaper.

Monoprice Monolith M15-S vs Rythmik FV15HP

On the Rythmik FV15HP side: 15-inch ported driver reaches 122.0dB CEA-2010-A average, matching the output of subwoofers costing significantly more. The tradeoff: Premium price ($1,770), ported design room gain dependency, and mid-to-large 52 kg (114.6 lbs) footprint.

Buy the Monoprice Monolith M15-S if the price matters more than sound quality. Buy the Rythmik FV15HP if sound quality matters more than the price.

Looking for alternatives? See the complete Subwoofers rankings.

Buy the Rythmik FV15HP at Rythmik Audio ($2,127) →

Specifications Side By Side

Monoprice Monolith M15-S Rythmik FV15HP
Price$999$1,770
Ranked#72 of 110 in Large Home Subwoofers (Over 75 lbs)#48 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosuresealedported, front
Output SPL at 15 Hz100.1 dB105.1 dB
Output SPL at 20 Hz105.6 dB111.1 dB
Output SPL at 25 Hz111.2 dB116.1 dB
Output SPL at 31.5 Hz115.2 dB120.0 dB
Output SPL at 40 Hz118.4 dB122.5 dB
Output SPL at 50 Hz119.3 dB122.1 dB
Output SPL at 63 Hz119.6 dB121.8 dB
Output SPL at 80 Hz118.9 dB121.4 dB
Output SPL at 100 Hz119.1 dB121.2 dB
Output SPL at 125 Hz118.9 dB121.1 dB
CEA-2010-A Average (40-80Hz)119.0 dB122.0 dB
Dimensions23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm)24.5"H x 18.2"W x 24.2"D (622.3 x 463.5 x 615.9 mm)
Warranty55/3
CountryUnited StatesUnited States
Measurement SourceManufacturerAudioholics
Weight80 lbs (36.3 kg)115.1 lbs (52.2 kg)
Drivers15" (381mm) driver15" (381mm) driver
Output SPL at 12.5 Hz-92.8 dB
Cabinet Color-black, white
Inputs-XLR (2), RCA (line/LFE)
XLR Input-Yes
RCA Input-Yes
TRS Input-No
Optical Input-No
Coaxial Input-No
USB Input-No
HDMI Input-No
AES Input-No
Aux Input-No
Buy the Rythmik FV15HP at Rythmik Audio ($2,127) →

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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

Monoprice Monolith M15-S: $999 eBay

Monoprice Monolith M15-S ranking card

Pros: Published CEA-2010 specifications list 105.6 dB at 20 Hz and 119.0 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver has the headroom for demanding film bass in a large room.

Cons: The 596.9H x 424.2W x 500.4D mm cabinet and 36.3 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.

Notes: Product # 35141

Full Monoprice Monolith M15-S review and specifications →

CEA-2010-A Average (40-80Hz)119.0 dB
CountryUnited States
Dimensions23.5"H x 16.7"W x 19.7"D (596.9 x 424.2 x 500.4 mm)
Drivers15" (381mm) driver
Enclosuresealed
Measurement SourceManufacturer
Output SPL at 15 Hz100.1 dB
Output SPL at 20 Hz105.6 dB
Output SPL at 25 Hz111.2 dB
Output SPL at 31.5 Hz115.2 dB
Output SPL at 40 Hz118.4 dB
Output SPL at 50 Hz119.3 dB
Output SPL at 63 Hz119.6 dB
Output SPL at 80 Hz118.9 dB
Output SPL at 100 Hz119.1 dB
Output SPL at 125 Hz118.9 dB
Warranty5
Weight80 lbs (36.3 kg)
Search eBay for Monoprice Monolith M15-S →

Rythmik FV15HP: $1,770 Rythmik Audio eBay

Rythmik FV15HP ranking card

Pros: 15-inch ported driver reaches 122.0dB CEA-2010-A average, matching the output of subwoofers costing significantly more.

Cons: Premium price ($2127), ported design room gain dependency, and mid-to-large 52 kg footprint.

Full Rythmik FV15HP review and specifications →

AES InputNo
Aux InputNo
CEA-2010-A Average (40-80Hz)122.0 dB
Cabinet Colorblack, white
Coaxial InputNo
CountryUnited States
Dimensions24.5"H x 18.2"W x 24.2"D (622.3 x 463.5 x 615.9 mm)
Drivers15" (381mm) driver
Enclosureported, front
HDMI InputNo
InputsXLR (2), RCA (line/LFE)
Measurement SourceAudioholics
Optical InputNo
Output SPL at 12.5 Hz92.8 dB
Output SPL at 15 Hz105.1 dB
Output SPL at 20 Hz111.1 dB
Output SPL at 25 Hz116.1 dB
Output SPL at 31.5 Hz120.0 dB
Output SPL at 40 Hz122.5 dB
Output SPL at 50 Hz122.1 dB
Output SPL at 63 Hz121.8 dB
Output SPL at 80 Hz121.4 dB
Output SPL at 100 Hz121.2 dB
Output SPL at 125 Hz121.1 dB
RCA InputYes
TRS InputNo
USB InputNo
Warranty5/3
Weight115.1 lbs (52.2 kg)
XLR InputYes
Check current price at Rythmik Audio ($2,127) →Search eBay for Rythmik FV15HP →