Monoprice Monolith 16 THX Ultra Review: Rated 4.4/5

Last updated: October 21, 2026

The Monoprice Monolith 16 THX Ultra is rated 4.4/5 for sound quality, #19 of 143 Large Home Subwoofers (Over 75 lbs). See all Subwoofers rankings for every top pick.

Monoprice Monolith 16 THX Ultra · Editor's rating 4.4/5, ranked #19 of 143 Large Home Subwoofers (Over 75 lbs)

Prices on this page were last checked October 28, 2026 at 1:06 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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Brand: Monoprice

#19 Monoprice Monolith 16 THX Ultra: $2,300 Discontinued eBay

Same family: the Monoprice Monolith 12 THX Ultra (smaller subwoofer, ranked lower, rated 3.8/5), the Monoprice Monolith 13 THX Ultra (smaller subwoofer, ranked lower, rated 4.2/5) and the Monoprice Monolith 15 THX Ultra (smaller subwoofer, ranked lower, rated 4.2/5). See every Monoprice Monolith generation.

Pros: A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used. 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. Discontinued.

Notes: Product # 42031

Is the Monoprice Monolith 16 THX Ultra right for you?

Skip it if

  • you need to move it often (78 kg each).
  • you want to buy it new: it is discontinued.
ReleasedOct 2021 (5 years ago)
AES InputNo
Aux InputNo
CEA-2010-A Average (40-80Hz)126.5 dB
Cabinet Colorblack
Coaxial InputNo
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
HDMI InputNo
InputsXLR, RCA, XLR out
Measurement SourceAudioholics
Optical InputNo
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
RCA InputYes
TRS InputNo
USB InputNo
Warranty5
Weight171.5 lbs (77.8 kg)
XLR InputYes
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