Klipsch R-121SW vs Monoprice Monolith M-10 V2

Last updated: September 20, 2026

Short answer: the Monoprice Monolith M-10 V2 for extension, the Klipsch R-121SW for the lower price. The M-10 V2 is a 10-inch THX-certified ported sub with 500W RMS that reaches 17-20Hz, at $753.97. The R-121SW costs $249, and its 12-inch spun-copper driver with 200W RMS delivers controlled, musical bass with minimal distortion.

Klipsch R-121SW vs Monoprice Monolith M-10 V2

The case for the Klipsch R-121SW: 12-inch spun-copper driver with 200W RMS delivers controlled, musical bass with minimal distortion.

What the Monoprice Monolith M-10 V2 gets right: 10-inch THX-certified ported with 500W RMS reaches 17-20Hz.

Buy the Klipsch R-121SW. It is rated higher for sound quality than the Monoprice Monolith M-10 V2 and costs less, which settles it without a real tradeoff to make.

Looking for alternatives? See the complete Subwoofers rankings.

Buy the Klipsch R-121SW at Amazon ($249.00) →Buy the Monoprice Monolith M-10 V2 at Amazon ($753.97) →

Specifications Side By Side

Klipsch R-121SW Monoprice Monolith M-10 V2
Price$249.00$753.97
Ranked#95 of 145 in Medium Home Subwoofers (30-75 lbs)#109 of 145 in Medium Home Subwoofers (30-75 lbs)
Enclosureported, rearported, front
Output SPL at 15 Hz90.7 dB93.9 dB
Output SPL at 20 Hz96.0 dB104.8 dB
Output SPL at 25 Hz98.4 dB108.5 dB
Output SPL at 31.5 Hz102.3 dB109.3 dB
Output SPL at 40 Hz108.2 dB109.7 dB
Output SPL at 50 Hz112.4 dB110.1 dB
Output SPL at 63 Hz112.9 dB110.6 dB
Output SPL at 80 Hz111.3 dB110.9 dB
Output SPL at 100 Hz109.9 dB111.2 dB
Output SPL at 125 Hz108.3 dB111.5 dB
CEA-2010-A Average (40-80Hz)111.2 dB110.3 dB
Dimensions16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm)20.9"H x 15"W x 18.9"D (530.9 x 381.0 x 480.1 mm)
Weight35.1 lbs (15.9 kg)72.5 lbs (32.9 kg)
Warranty5/25
Cabinet Colorblackblack
CountryUnited StatesUnited States
Measurement SourceAudioholicsManufacturer
Amplifier Power200W RMS500W RMS
Frequency Response28-120Hz17-20Hz
Drivers12" (305mm) driver10" (254mm) driver
Inputs-XLR, RCA, XLR passthrough out
XLR Input-Yes
RCA Input-Yes
TRS Input-No
Optical Input-No
Coaxial Input-No
USB Input-No
HDMI Input-No
AES Input-No
Aux Input-No
Buy the Klipsch R-121SW at Amazon ($249.00) →Buy the Monoprice Monolith M-10 V2 at Amazon ($753.97) →

More top alternatives to Klipsch R-121SW:

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

Klipsch R-121SW: $249.00 Amazon eBay

Klipsch R-121SW ranking card

Pros: 12-inch spun-copper driver with 200W RMS delivers controlled, musical bass with minimal distortion. Front-firing design maximizes placement flexibility. Excellent value with exceptional bang-for-buck.

Full Klipsch R-121SW review and specifications →

Amplifier Power200W RMS
CEA-2010-A Average (40-80Hz)111.2 dB
Cabinet Colorblack
CountryUnited States
Dimensions16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm)
Drivers12" (305mm) driver
Enclosureported, rear
Frequency Response28-120Hz
Measurement SourceAudioholics
Output SPL at 15 Hz90.7 dB
Output SPL at 20 Hz96.0 dB
Output SPL at 25 Hz98.4 dB
Output SPL at 31.5 Hz102.3 dB
Output SPL at 40 Hz108.2 dB
Output SPL at 50 Hz112.4 dB
Output SPL at 63 Hz112.9 dB
Output SPL at 80 Hz111.3 dB
Output SPL at 100 Hz109.9 dB
Output SPL at 125 Hz108.3 dB
Warranty5/2
Weight35.1 lbs (15.9 kg)
Check current price at Amazon ($249.00) →Search eBay for Klipsch R-121SW →

Monoprice Monolith M-10 V2: $753.97 Amazon eBay

Monoprice Monolith M-10 V2 ranking card

Pros: 10-inch THX-certified ported with 500W RMS reaches 17-20Hz. HDF cabinet eliminates resonance-induced coloration. Extended EQ and THX EQ modes for flexibility. Low distortion output. Best for rooms under 2500 cubic feet. Exceptional budget value at $754.

Notes: Product # 42843

Full Monoprice Monolith M-10 V2 review and specifications →

AES InputNo
Amplifier Power500W RMS
Aux InputNo
CEA-2010-A Average (40-80Hz)110.3 dB
Cabinet Colorblack
Coaxial InputNo
CountryUnited States
Dimensions20.9"H x 15"W x 18.9"D (530.9 x 381.0 x 480.1 mm)
Drivers10" (254mm) driver
Enclosureported, front
Frequency Response17-20Hz
HDMI InputNo
InputsXLR, RCA, XLR passthrough out
Measurement SourceManufacturer
Optical InputNo
Output SPL at 15 Hz93.9 dB
Output SPL at 20 Hz104.8 dB
Output SPL at 25 Hz108.5 dB
Output SPL at 31.5 Hz109.3 dB
Output SPL at 40 Hz109.7 dB
Output SPL at 50 Hz110.1 dB
Output SPL at 63 Hz110.6 dB
Output SPL at 80 Hz110.9 dB
Output SPL at 100 Hz111.2 dB
Output SPL at 125 Hz111.5 dB
RCA InputYes
TRS InputNo
USB InputNo
Warranty5
Weight72.5 lbs (32.9 kg)
XLR InputYes
Check current price at Amazon ($753.97) →Search eBay for Monoprice Monolith M-10 V2 →