Short answer: the Monoprice SSW-10 if depth of cabinet matters, the Klipsch R-121SW for driver size and power. The SSW-10 is an ultra-slim sealed 10-inch sub just 7 inches tall with 150W RMS and a 108.2dB average output, costing $195.99. The R-121SW costs $249 and uses a 12-inch spun-copper driver with 200W RMS for controlled, musical bass with minimal distortion.
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 SSW-10 gets right: 10-inch ultra-slim sealed (7” height) with 150W RMS, 108.2dB average.
Buy the Monoprice SSW-10. It is rated higher for sound quality than the Klipsch R-121SW and costs less, so the other one has nothing left to offer.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Klipsch R-121SW | Monoprice SSW-10 | |
|---|---|---|
| Price | $249.00 | $195.99 |
| Ranked | #95 of 145 in Medium Home Subwoofers (30-75 lbs) | #72 of 145 in Medium Home Subwoofers (30-75 lbs) |
| Enclosure | ported, rear | sealed |
| Output SPL at 15 Hz | 90.7 dB | - |
| Output SPL at 20 Hz | 96.0 dB | 76.8 dB |
| Output SPL at 25 Hz | 98.4 dB | 85.2 dB |
| Output SPL at 31.5 Hz | 102.3 dB | 96.8 dB |
| Output SPL at 40 Hz | 108.2 dB | 105.7 dB |
| Output SPL at 50 Hz | 112.4 dB | 110.7 dB |
| Output SPL at 63 Hz | 112.9 dB | 118.4 dB |
| Output SPL at 80 Hz | 111.3 dB | 122.1 dB |
| Output SPL at 100 Hz | 109.9 dB | - |
| Output SPL at 125 Hz | 108.3 dB | - |
| CEA-2010-A Average (40-80Hz) | 111.2 dB | 114.2 dB |
| Dimensions | 16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm) | 7"H x 25"W x 15.7"D (177.8 x 635.0 x 398.8 mm) |
| Weight | 35.1 lbs (15.9 kg) | 30 lbs (13.6 kg) |
| Warranty | 5/2 | 1 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Amplifier Power | 200W RMS | 150W RMS |
| Frequency Response | 28-120Hz | 25Hz+ |
| Drivers | 12" (305mm) driver | 10" (254mm) driver |
Related Speaker Comparisons
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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
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 Power | 200W RMS |
|---|---|
| CEA-2010-A Average (40-80Hz) | 111.2 dB |
| Cabinet Color | black |
| Country | United States |
| Dimensions | 16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm) |
| Drivers | 12" (305mm) driver |
| Enclosure | ported, rear |
| Frequency Response | 28-120Hz |
| Measurement Source | Audioholics |
| Output SPL at 15 Hz | 90.7 dB |
| Output SPL at 20 Hz | 96.0 dB |
| Output SPL at 25 Hz | 98.4 dB |
| Output SPL at 31.5 Hz | 102.3 dB |
| Output SPL at 40 Hz | 108.2 dB |
| Output SPL at 50 Hz | 112.4 dB |
| Output SPL at 63 Hz | 112.9 dB |
| Output SPL at 80 Hz | 111.3 dB |
| Output SPL at 100 Hz | 109.9 dB |
| Output SPL at 125 Hz | 108.3 dB |
| Warranty | 5/2 |
| Weight | 35.1 lbs (15.9 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Audioholics; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- Klipsch R-121SW vs RSL (Rogersound Labs) Speedwoofer 10S MKII
- Klipsch R-121SW vs Monoprice Monolith M-10 V2
- Klipsch R-121SW vs Kef KC62
- Klipsch R-121SW vs SVS PB-1000 PRO
- Klipsch R-121SW vs SVS SB-2000
- Klipsch R-121SW vs JBL HDI-1200P
- Klipsch R-121SW vs Power Sound Audio (PSA) XS15SE
- Klipsch R-121SW vs Rythmik F12
- See all 17 comparisons
Monoprice SSW-10: $195.99 Amazon eBay
Pros: 10-inch ultra-slim sealed (7” height) with 150W RMS, 108.2dB average. Hidden under furniture or placement flexibility. Compact design at $196 price. Decent output for slim profile.
Notes: Product # 33830, low profile (<8in)
Full Monoprice SSW-10 review and specifications →
| Amplifier Power | 150W RMS |
|---|---|
| CEA-2010-A Average (40-80Hz) | 114.2 dB |
| Cabinet Color | black |
| Country | United States |
| Dimensions | 7"H x 25"W x 15.7"D (177.8 x 635.0 x 398.8 mm) |
| Drivers | 10" (254mm) driver |
| Enclosure | sealed |
| Frequency Response | 25Hz+ |
| Measurement Source | Brent Butterworth |
| Output SPL at 20 Hz | 76.8 dB |
| Output SPL at 25 Hz | 85.2 dB |
| Output SPL at 31.5 Hz | 96.8 dB |
| Output SPL at 40 Hz | 105.7 dB |
| Output SPL at 50 Hz | 110.7 dB |
| Output SPL at 63 Hz | 118.4 dB |
| Output SPL at 80 Hz | 122.1 dB |
| Warranty | 1 |
| Weight | 30 lbs (13.6 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Brent Butterworth; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- Monoprice SSW-10 vs BIC America PL-300
- Monoprice SSW-10 vs RSL (Rogersound Labs) Speedwoofer 10S MKII
- Monoprice SSW-10 vs Monitor Audio RXW12
- Monoprice SSW-10 vs SVS PB-1000 PRO
- Monoprice SSW-10 vs Monoprice Monolith M-10 V2
- Monoprice SSW-10 vs SVS SB-2000
- Monoprice SSW-10 vs Power Sound Audio (PSA) XS15SE
- Monoprice SSW-10 vs Rythmik F12
- See all 17 comparisons