Monoprice Monolith 16 THX Ultra vs REL Acoustics HT/1510 Predator II

Last updated: September 14, 2026

Short answer: the Monoprice Monolith 16 THX Ultra. It ranks #18 of 110 subwoofers by sound quality at $2300; the REL Acoustics HT/1510 Predator II ranks #82 and costs $2526.62, so there is little reason to consider the other one.

Monoprice Monolith 16 THX Ultra vs REL Acoustics HT/1510 Predator II

What the Monoprice Monolith 16 THX Ultra offers: 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. Watch for: Heavy at 78 kg and ported design can interact with room acoustics.

What the REL Acoustics HT/1510 Predator II offers: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 118.1 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music. Watch for: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 457.2H x 541.0W x 492.8D mm cabinet and 45.2 kg mass still require deliberate placement and calibration.

Buy the Monoprice Monolith 16 THX Ultra. It ranks higher for sound quality than the REL Acoustics HT/1510 Predator II and costs less, so there is no real case for the other one.

Still deciding? The full Subwoofers rankings cover every ranked option.

Specifications Side By Side

Monoprice Monolith 16 THX Ultra REL Acoustics HT/1510 Predator II
Price$2,300$2,526.62
Ranked#18 of 110 in Large Home Subwoofers (Over 75 lbs)#82 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosureported, frontsealed
Output SPL at 15 Hz107.3 dB91.4 dB
Output SPL at 20 Hz118.4 dB98.0 dB
Output SPL at 25 Hz123.3 dB104.4 dB
Output SPL at 31.5 Hz125.1 dB111.1 dB
Output SPL at 40 Hz126.3 dB116.9 dB
Output SPL at 50 Hz126.5 dB118.5 dB
Output SPL at 63 Hz126.6 dB118.5 dB
Output SPL at 80 Hz126.8 dB118.4 dB
Output SPL at 100 Hz127.2 dB118.5 dB
Output SPL at 125 Hz127.6 dB118.0 dB
CEA-2010-A Average (40-80Hz)126.5 dB118.1 dB
Dimensions25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm)18"H x 21.3"W x 19.4"D (457.2 x 541.0 x 492.8 mm)
Weight171.5 lbs (77.8 kg)99.6 lbs (45.2 kg)
Warranty53
Cabinet Colorblackblack
CountryUnited StatesUnited Kingdom
Measurement SourceAudioholicsAudioholics
Drivers16" (406mm) driver15" (381mm) driver

How Monoprice Monolith 16 THX Ultra compares with other leading options:

Prices on this page were last checked September 14, 2026 at 1:47 AM 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 16 THX Ultra: $2,300 eBay

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

Full Monoprice Monolith 16 THX Ultra review and specifications →

CEA-2010-A Average (40-80Hz)126.5 dB
Cabinet Colorblack
CountryUnited States
Dimensions25.6"H x 22"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)
Search eBay for Monoprice Monolith 16 THX Ultra →

REL Acoustics HT/1510 Predator II: $2,526.62 eBay

REL Acoustics HT/1510 Predator II ranking card

Pros: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 118.1 dB through 40-80 Hz. The sealed enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music.

Cons: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 457.2H x 541.0W x 492.8D mm cabinet and 45.2 kg mass still require deliberate placement and calibration.

Full REL Acoustics HT/1510 Predator II review and specifications →

CEA-2010-A Average (40-80Hz)118.1 dB
Cabinet Colorblack
CountryUnited Kingdom
Dimensions18"H x 21.3"W x 19.4"D (457.2 x 541.0 x 492.8 mm)
Drivers15" (381mm) driver
Enclosuresealed
Measurement SourceAudioholics
Output SPL at 15 Hz91.4 dB
Output SPL at 20 Hz98.0 dB
Output SPL at 25 Hz104.4 dB
Output SPL at 31.5 Hz111.1 dB
Output SPL at 40 Hz116.9 dB
Output SPL at 50 Hz118.5 dB
Output SPL at 63 Hz118.5 dB
Output SPL at 80 Hz118.4 dB
Output SPL at 100 Hz118.5 dB
Output SPL at 125 Hz118.0 dB
Warranty3
Weight99.6 lbs (45.2 kg)
Search eBay for REL Acoustics HT/1510 Predator II →