Short answer: the Monoprice Monolith 16 THX Ultra for better sound quality, the Klipsch R-115SW for the lower price. The Monoprice Monolith 16 THX Ultra ranks #18 of 110 subwoofers at $2300. The Klipsch R-115SW ranks #65 at $799, $1501 cheaper.
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 Klipsch R-115SW offers: Independent CEA-2010 testing records 108.7 dB at 20 Hz and 123.1 dB (avg of 3/4 bands) through 40-80 Hz. The ported, front enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music. Watch for: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 546.1H x 495.3W x 566.4D mm cabinet and 34.2 kg mass still require deliberate placement and calibration.
Buy the Monoprice Monolith 16 THX Ultra when sound quality outweighs the price for you, and the Klipsch R-115SW when the price outweighs sound quality instead.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | Klipsch R-115SW | |
|---|---|---|
| Price | $2,300 | $799 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #65 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | - |
| Output SPL at 20 Hz | 118.4 dB | 108.7 dB |
| Output SPL at 25 Hz | 123.3 dB | 113.8 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 118.6 dB |
| Output SPL at 40 Hz | 126.3 dB | 121.4 dB |
| Output SPL at 50 Hz | 126.5 dB | 124.7 dB |
| Output SPL at 63 Hz | 126.6 dB | 123.3 dB |
| Output SPL at 80 Hz | 126.8 dB | - |
| Output SPL at 100 Hz | 127.2 dB | - |
| Output SPL at 125 Hz | 127.6 dB | - |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 123.1 dB (avg of 3/4 bands) |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) | 21.5"H x 19.5"W x 22.3"D (546.1 x 495.3 x 566.4 mm) |
| Weight | 171.5 lbs (77.8 kg) | 75.4 lbs (34.2 kg) |
| Warranty | 5 | 5/2 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 16" (406mm) driver | 15" (381mm) driver |
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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
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 Color | black |
| Country | United States |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) |
| Drivers | 16" (406mm) driver |
| Enclosure | ported, front |
| Measurement Source | Audioholics |
| Output SPL at 15 Hz | 107.3 dB |
| Output SPL at 20 Hz | 118.4 dB |
| Output SPL at 25 Hz | 123.3 dB |
| Output SPL at 31.5 Hz | 125.1 dB |
| Output SPL at 40 Hz | 126.3 dB |
| Output SPL at 50 Hz | 126.5 dB |
| Output SPL at 63 Hz | 126.6 dB |
| Output SPL at 80 Hz | 126.8 dB |
| Output SPL at 100 Hz | 127.2 dB |
| Output SPL at 125 Hz | 127.6 dB |
| Warranty | 5 |
| Weight | 171.5 lbs (77.8 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
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Klipsch R-115SW: $799 eBay
Pros: Independent CEA-2010 testing records 108.7 dB at 20 Hz and 123.1 dB (avg of 3/4 bands) through 40-80 Hz. The ported, front enclosure with 15” (381mm) driver delivers substantial upper-bass output for movie effects and music.
Cons: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 546.1H x 495.3W x 566.4D mm cabinet and 34.2 kg mass still require deliberate placement and calibration.
Full Klipsch R-115SW review and specifications →
| CEA-2010-A Average (40-80Hz) | 123.1 dB (avg of 3/4 bands) |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 21.5"H x 19.5"W x 22.3"D (546.1 x 495.3 x 566.4 mm) |
| Drivers | 15" (381mm) driver |
| Enclosure | ported, front |
| Measurement Source | Brent Butterworth |
| Output SPL at 20 Hz | 108.7 dB |
| Output SPL at 25 Hz | 113.8 dB |
| Output SPL at 31.5 Hz | 118.6 dB |
| Output SPL at 40 Hz | 121.4 dB |
| Output SPL at 50 Hz | 124.7 dB |
| Output SPL at 63 Hz | 123.3 dB |
| Warranty | 5/2 |
| Weight | 75.4 lbs (34.2 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