Monoprice Monolith 16 THX Ultra vs XTZ Sound SUB 3X12

Last updated: September 14, 2026

Short answer: the Monoprice Monolith 16 THX Ultra on measured sound quality, the XTZ Sound SUB 3X12 on price. The Monoprice Monolith 16 THX Ultra ranks #18 of 110 subwoofers at $2300. The XTZ Sound SUB 3X12 ranks #26 at $1412.84, $887.16 cheaper.

Monoprice Monolith 16 THX Ultra vs XTZ Sound SUB 3X12

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 XTZ Sound SUB 3X12 offers: Independent CEA-2010 testing records 114.5 dB at 20 Hz and 125.3 dB through 40-80 Hz. The ported, front enclosure with 3x 12” (305mm) drivers has the headroom for demanding film bass in a large room. Watch for: The 1158.2H x 535.9W x 556.3D mm cabinet and 77.4 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 XTZ Sound SUB 3X12 when the price outweighs sound quality instead.

Looking for alternatives? See the complete Subwoofers rankings.

Specifications Side By Side

Monoprice Monolith 16 THX Ultra XTZ Sound SUB 3X12
Price$2,300$1,412.84
Ranked#18 of 110 in Large Home Subwoofers (Over 75 lbs)#26 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, front
Output SPL at 15 Hz107.3 dB109.1 dB
Output SPL at 20 Hz118.4 dB114.5 dB
Output SPL at 25 Hz123.3 dB118.5 dB
Output SPL at 31.5 Hz125.1 dB121.8 dB
Output SPL at 40 Hz126.3 dB124.8 dB
Output SPL at 50 Hz126.5 dB125.4 dB
Output SPL at 63 Hz126.6 dB125.4 dB
Output SPL at 80 Hz126.8 dB125.6 dB
Output SPL at 100 Hz127.2 dB126.1 dB
Output SPL at 125 Hz127.6 dB126.4 dB
CEA-2010-A Average (40-80Hz)126.5 dB125.3 dB
Dimensions25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm)45.6"H x 21.1"W x 21.9"D (1158.2 x 535.9 x 556.3 mm)
Weight171.5 lbs (77.8 kg)170.6 lbs (77.4 kg)
Warranty55/2
Cabinet Colorblackblack
CountryUnited StatesSweden
Measurement SourceAudioholicsAudioholics
Drivers16" (406mm) driver3x 12" (305mm) drivers
Output SPL at 12.5 Hz-100.0 dB

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

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 →

XTZ Sound SUB 3X12: $1,412.84 eBay

XTZ Sound SUB 3X12 ranking card

Pros: Independent CEA-2010 testing records 114.5 dB at 20 Hz and 125.3 dB through 40-80 Hz. The ported, front enclosure with 3x 12” (305mm) drivers has the headroom for demanding film bass in a large room.

Cons: The 1158.2H x 535.9W x 556.3D mm cabinet and 77.4 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.

Full XTZ Sound SUB 3X12 review and specifications →

CEA-2010-A Average (40-80Hz)125.3 dB
Cabinet Colorblack
CountrySweden
Dimensions45.6"H x 21.1"W x 21.9"D (1158.2 x 535.9 x 556.3 mm)
Drivers3x 12" (305mm) drivers
Enclosureported, front
Measurement SourceAudioholics
Output SPL at 12.5 Hz100.0 dB
Output SPL at 15 Hz109.1 dB
Output SPL at 20 Hz114.5 dB
Output SPL at 25 Hz118.5 dB
Output SPL at 31.5 Hz121.8 dB
Output SPL at 40 Hz124.8 dB
Output SPL at 50 Hz125.4 dB
Output SPL at 63 Hz125.4 dB
Output SPL at 80 Hz125.6 dB
Output SPL at 100 Hz126.1 dB
Output SPL at 125 Hz126.4 dB
Warranty5/2
Weight170.6 lbs (77.4 kg)
Search eBay for XTZ Sound SUB 3X12 →