Monoprice Monolith 16 THX Ultra vs Monoprice Monolith 12 THX Ultra

Last updated: September 16, 2026

Short answer: the Monoprice Monolith 16 THX Ultra for better sound quality, the Monoprice Monolith 12 THX Ultra for the lower price. The Monoprice Monolith 16 THX Ultra ranks #18 of 110 subwoofers at $2300. The Monoprice Monolith 12 THX Ultra ranks #94 at $1499, $801 cheaper.

Monoprice Monolith 16 THX Ultra vs Monoprice Monolith 12 THX Ultra

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 Monoprice Monolith 12 THX Ultra offers: Independent CEA-2010 testing records 108.4 dB at 20 Hz and 115.2 dB through 40-80 Hz. The ported, front enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room. Watch for: The 579.1H x 424.2W x 599.4D mm cabinet and 44.7 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Buy the Monoprice Monolith 16 THX Ultra when sound quality outweighs the price for you, and the Monoprice Monolith 12 THX Ultra when the price outweighs sound quality instead.

Skip the Monoprice Monolith 12 THX Ultra if sound quality matters to you. It ranks near the bottom of the 110 subwoofers.

Want more options? Browse the full Subwoofers rankings.

Specifications Side By Side

Monoprice Monolith 16 THX Ultra Monoprice Monolith 12 THX Ultra
Price$2,300$1499
Ranked#18 of 110 in Large Home Subwoofers (Over 75 lbs)#94 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, front
Output SPL at 15 Hz107.3 dB101.2 dB
Output SPL at 20 Hz118.4 dB108.4 dB
Output SPL at 25 Hz123.3 dB110.9 dB
Output SPL at 31.5 Hz125.1 dB113.0 dB
Output SPL at 40 Hz126.3 dB114.0 dB
Output SPL at 50 Hz126.5 dB115.0 dB
Output SPL at 63 Hz126.6 dB116.0 dB
Output SPL at 80 Hz126.8 dB116.0 dB
Output SPL at 100 Hz127.2 dB115.0 dB
Output SPL at 125 Hz127.6 dB114.0 dB
CEA-2010-A Average (40-80Hz)126.5 dB115.2 dB
Dimensions25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm)22.8"H x 16.7"W x 23.6"D (579.1 x 424.2 x 599.4 mm)
Weight171.5 lbs (77.8 kg)98.5 lbs (44.7 kg)
Warranty55
Cabinet Colorblackblack
CountryUnited StatesUnited States
Measurement SourceAudioholicsErinsAudioCorner
Drivers16" (406mm) driver12" (305mm) driver
Output SPL at 12.5 Hz-87.7 dB

More worthwhile head-to-heads for Monoprice Monolith 16 THX Ultra:

Prices on this page were last checked September 16, 2026 at 12:41 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 →

Monoprice Monolith 12 THX Ultra: $1499 eBay

Monoprice Monolith 12 THX Ultra ranking card

Pros: Independent CEA-2010 testing records 108.4 dB at 20 Hz and 115.2 dB through 40-80 Hz. The ported, front enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room.

Cons: The 579.1H x 424.2W x 599.4D mm cabinet and 44.7 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 # 24457

Full Monoprice Monolith 12 THX Ultra review and specifications →

CEA-2010-A Average (40-80Hz)115.2 dB
Cabinet Colorblack
CountryUnited States
Dimensions22.8"H x 16.7"W x 23.6"D (579.1 x 424.2 x 599.4 mm)
Drivers12" (305mm) driver
Enclosureported, front
Measurement SourceErinsAudioCorner
Output SPL at 12.5 Hz87.7 dB
Output SPL at 15 Hz101.2 dB
Output SPL at 20 Hz108.4 dB
Output SPL at 25 Hz110.9 dB
Output SPL at 31.5 Hz113.0 dB
Output SPL at 40 Hz114.0 dB
Output SPL at 50 Hz115.0 dB
Output SPL at 63 Hz116.0 dB
Output SPL at 80 Hz116.0 dB
Output SPL at 100 Hz115.0 dB
Output SPL at 125 Hz114.0 dB
Warranty5
Weight98.5 lbs (44.7 kg)
Search eBay for Monoprice Monolith 12 THX Ultra →