Funk Audio Ultra 21.0LX vs Monoprice Monolith 16 THX Ultra

Last updated: September 17, 2026

Short answer: the Monoprice Monolith 16 THX Ultra. Both are rated 4.4/5 for sound quality (#18 and #19 of 110 subwoofers), and the Monoprice Monolith 16 THX Ultra costs $2300 against $9487.26 for the Funk Audio Ultra 21.0LX, with sound quality a draw, the lower price decides it.

Funk Audio Ultra 21.0LX vs Monoprice Monolith 16 THX Ultra

On the Monoprice Monolith 16 THX Ultra side: 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. Set against that: Heavy at 78 kg (172 lbs) and ported design can interact with room acoustics.

Buy the Monoprice Monolith 16 THX Ultra. Both are rated the same for sound quality, and it costs $7187.26 less than the Funk Audio Ultra 21.0LX.

Looking for alternatives? See the complete Subwoofers rankings.

Specifications Side By Side

Funk Audio Ultra 21.0LX Monoprice Monolith 16 THX Ultra
Price$9,487.26$2,300
Ranked#19 of 110 in Large Home Subwoofers (Over 75 lbs)#18 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosuresealedported, front
Output SPL at 10 Hz99.9 dB-
Output SPL at 12.5 Hz102.3 dB-
Output SPL at 15 Hz108.4 dB107.3 dB
Output SPL at 20 Hz116.6 dB118.4 dB
Output SPL at 25 Hz120.5 dB123.3 dB
Output SPL at 31.5 Hz121.2 dB125.1 dB
Output SPL at 40 Hz125.0 dB126.3 dB
Output SPL at 50 Hz127.2 dB126.5 dB
Output SPL at 63 Hz126.5 dB126.6 dB
Output SPL at 80 Hz126.6 dB126.8 dB
Output SPL at 100 Hz127.6 dB127.2 dB
CEA-2010-A Average (40-80Hz)126.3 dB126.5 dB
Dimensions25.5"H x 24.5"W x 24"D (647.7 x 622.3 x 609.6 mm)25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm)
Weight145.1 lbs (65.8 kg)171.5 lbs (77.8 kg)
Warranty35
Cabinet Colorwood, customblack
CountryCanadaUnited States
Measurement SourceManufacturerAudioholics
Drivers21" (533mm) driver16" (406mm) driver
InputsXLR (balanced)XLR, RCA, XLR out
XLR InputYesYes
RCA InputNoYes
TRS InputNoNo
Optical InputNoNo
Coaxial InputNoNo
USB InputNoNo
HDMI InputNoNo
AES InputNoNo
Aux InputNoNo
Output SPL at 125 Hz-127.6 dB

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

Prices on this page were last checked September 23, 2026 at 11:24 PM 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

Funk Audio Ultra 21.0LX: $9,487.26 eBay

Funk Audio Ultra 21.0LX ranking card

Pros: Published CEA-2010 specifications list 116.6 dB at 20 Hz and 126.3 dB through 40-80 Hz. The sealed enclosure with 21” (533mm) driver has the headroom for demanding film bass in a large room.

Cons: The 647.7H x 622.3W x 609.6D mm cabinet and 65.8 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.

Full Funk Audio Ultra 21.0LX review and specifications →

AES InputNo
Aux InputNo
CEA-2010-A Average (40-80Hz)126.3 dB
Cabinet Colorwood, custom
Coaxial InputNo
CountryCanada
Dimensions25.5"H x 24.5"W x 24"D (647.7 x 622.3 x 609.6 mm)
Drivers21" (533mm) driver
Enclosuresealed
HDMI InputNo
InputsXLR (balanced)
Measurement SourceManufacturer
Optical InputNo
Output SPL at 10 Hz99.9 dB
Output SPL at 12.5 Hz102.3 dB
Output SPL at 15 Hz108.4 dB
Output SPL at 20 Hz116.6 dB
Output SPL at 25 Hz120.5 dB
Output SPL at 31.5 Hz121.2 dB
Output SPL at 40 Hz125.0 dB
Output SPL at 50 Hz127.2 dB
Output SPL at 63 Hz126.5 dB
Output SPL at 80 Hz126.6 dB
Output SPL at 100 Hz127.6 dB
RCA InputNo
TRS InputNo
USB InputNo
Warranty3
Weight145.1 lbs (65.8 kg)
XLR InputYes
Search eBay for Funk Audio Ultra 21.0LX →

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 →

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
Search eBay for Monoprice Monolith 16 THX Ultra →