Monoprice Monolith 16 THX Ultra vs Rythmik FV15HP

Last updated: August 9, 2026

Short answer: the Monoprice Monolith 16 THX Ultra for the higher ranking, the Rythmik FV15HP for the lower price. The Monoprice Monolith 16 THX Ultra ranks #13 of 97 subwoofers at $2300. The Rythmik FV15HP ranks #39 at $1770, $530 cheaper.

What the Monoprice Monolith 16 THX Ultra gets right: 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.

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

Buy the Monoprice Monolith 16 THX Ultra if the ranking matters more than the price. Buy the Rythmik FV15HP if the price matters more than the ranking.

Specifications Side By Side

Monoprice Monolith 16 THX Ultra Rythmik FV15HP
Price$2,300$1,770
Ranked#13 of 97 in Large Powered Home Subwoofers (Over 75 lbs)#39 of 97 in Large Powered Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, front
Output SPL at 15 Hz107.3 dB105.1 dB
Output SPL at 20 Hz118.4 dB111.1 dB
Output SPL at 25 Hz123.3 dB116.1 dB
Output SPL at 31.5 Hz125.1 dB120.0 dB
Output SPL at 40 Hz126.3 dB122.5 dB
Output SPL at 50 Hz126.5 dB122.1 dB
Output SPL at 63 Hz126.6 dB121.8 dB
Output SPL at 80 Hz126.8 dB121.4 dB
Output SPL at 100 Hz127.2 dB121.2 dB
Output SPL at 125 Hz127.6 dB121.1 dB
CEA-2010-A Average (40-80Hz)126.5 dB122.0 dB
Dimensions25.6"H x 22.0"W x 28.1"D (650.2 x 558.8 x 713.7 mm)24.5"H x 18.25"W x 24.25"D (622.3 x 463.5 x 615.9 mm)
Weight171.5 lbs / 77.8 kg115.1 lbs / 52.2 kg
Warranty55/3
Cabinet Colorblackblack, white
CountryUnited StatesUnited States
Measurement SourceAudioholicsAudioholics
Drivers16" (406mm) driver15" (381mm) driver
Output SPL at 12.5 Hz-92.8 dB

The Two Speakers In Full

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

Rythmik FV15HP: $1,770

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 ($1,770), ported design room gain dependency, and mid-to-large 52 kg footprint.

CEA-2010-A Average (40-80Hz)122.0 dB
Cabinet Colorblack, white
CountryUnited States
Dimensions24.5"H x 18.25"W x 24.25"D (622.3 x 463.5 x 615.9 mm)
Drivers15" (381mm) driver
Enclosureported, front
Measurement SourceAudioholics
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
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.