Monoprice Monolith 16 THX Ultra vs RSL (Rogersound Labs) Speedwoofer 12S

Last updated: September 16, 2026

Short answer: the Monoprice Monolith 16 THX Ultra for better sound quality, the RSL (Rogersound Labs) Speedwoofer 12S for the lower price. The Monoprice Monolith 16 THX Ultra ranks #18 of 110 subwoofers at $2300. The RSL (Rogersound Labs) Speedwoofer 12S ranks #98 at $800, $1500 cheaper.

Monoprice Monolith 16 THX Ultra vs RSL (Rogersound Labs) Speedwoofer 12S

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 RSL (Rogersound Labs) Speedwoofer 12S offers: Independent CEA-2010 testing records 109.3 dB at 20 Hz and 113.2 dB through 40-80 Hz. The ported, rear enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room. Watch for: The 565.1H x 479.4W x 562.0D mm cabinet and 37.2 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 RSL (Rogersound Labs) Speedwoofer 12S when the price outweighs sound quality instead.

The RSL (Rogersound Labs) Speedwoofer 12S is not a sound-quality pick. It sits near the bottom of the 110 subwoofers; there are better options higher up.

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

Specifications Side By Side

Monoprice Monolith 16 THX Ultra RSL (Rogersound Labs) Speedwoofer 12S
Price$2,300$800
Ranked#18 of 110 in Large Home Subwoofers (Over 75 lbs)#98 of 110 in Large Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, rear
Output SPL at 15 Hz107.3 dB104.4 dB
Output SPL at 20 Hz118.4 dB109.3 dB
Output SPL at 25 Hz123.3 dB110.9 dB
Output SPL at 31.5 Hz125.1 dB112.5 dB
Output SPL at 40 Hz126.3 dB113.4 dB
Output SPL at 50 Hz126.5 dB113.4 dB
Output SPL at 63 Hz126.6 dB113.0 dB
Output SPL at 80 Hz126.8 dB113.1 dB
Output SPL at 100 Hz127.2 dB112.2 dB
Output SPL at 125 Hz127.6 dB-
CEA-2010-A Average (40-80Hz)126.5 dB113.2 dB
Dimensions25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm)22.2"H x 18.9"W x 22.1"D (565.1 x 479.4 x 562.0 mm)
Weight171.5 lbs (77.8 kg)82 lbs (37.2 kg)
Warranty5?
Cabinet Colorblackblack, white
CountryUnited StatesUnited States
Measurement SourceAudioholicsErinsAudioCorner
Drivers16" (406mm) driver12" (305mm) driver

More top alternatives to 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 →

RSL (Rogersound Labs) Speedwoofer 12S: $800 eBay

RSL (Rogersound Labs) Speedwoofer 12S ranking card

Pros: Independent CEA-2010 testing records 109.3 dB at 20 Hz and 113.2 dB through 40-80 Hz. The ported, rear enclosure with 12” (305mm) driver has the headroom for demanding film bass in a large room.

Cons: The 565.1H x 479.4W x 562.0D mm cabinet and 37.2 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 RSL (Rogersound Labs) Speedwoofer 12S review and specifications →

CEA-2010-A Average (40-80Hz)113.2 dB
Cabinet Colorblack, white
CountryUnited States
Dimensions22.2"H x 18.9"W x 22.1"D (565.1 x 479.4 x 562.0 mm)
Drivers12" (305mm) driver
Enclosureported, rear
Measurement SourceErinsAudioCorner
Output SPL at 15 Hz104.4 dB
Output SPL at 20 Hz109.3 dB
Output SPL at 25 Hz110.9 dB
Output SPL at 31.5 Hz112.5 dB
Output SPL at 40 Hz113.4 dB
Output SPL at 50 Hz113.4 dB
Output SPL at 63 Hz113.0 dB
Output SPL at 80 Hz113.1 dB
Output SPL at 100 Hz112.2 dB
Warranty?
Weight82 lbs (37.2 kg)
Search eBay for RSL (Rogersound Labs) Speedwoofer 12S →