The Monoprice THX 121456 ranks #109 out of 110 total Large Home Subwoofers (Over 75 lbs) for sound quality. See all Subwoofers rankings for every top pick.
Brand: Monoprice
Prices on this page were last checked September 14, 2026 at 1:47 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.
As an eBay Partner, we may be compensated if you make a purchase.
#109 Monoprice THX 121456: $899 eBay
Pros: Independent CEA-2010 testing records 94.6 dB at 20 Hz and 108.0 dB through 40-80 Hz. The subwoofer enclosure with 12” (305mm) 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 0.0H x 0.0W x 0.0D mm cabinet and 44.7 kg mass still require deliberate placement and calibration.
Notes: Product # 121456
How it compares: Just above it: SVS SB13-Plus - $500 more. Just below it: Sonus Faber Gravis VI - $7080 more, 1.7dB less max output.
| CEA-2010-A Average (40-80Hz) | 108.0 dB |
|---|---|
| Country | United States |
| Dimensions | 0"H x 0"W x 0"D (0.0 x 0.0 x 0.0 mm) |
| Drivers | 12" (305mm) driver |
| Measurement Source | Brent Butterworth |
| Output SPL at 15 Hz | 92.0 dB |
| Output SPL at 20 Hz | 94.6 dB |
| Output SPL at 25 Hz | 100.1 dB |
| Output SPL at 31.5 Hz | 103.2 dB |
| Output SPL at 40 Hz | 104.7 dB |
| Output SPL at 50 Hz | 107.3 dB |
| Output SPL at 63 Hz | 109.3 dB |
| Output SPL at 80 Hz | 110.5 dB |
| Weight | 98.5 lbs (44.7 kg) |
- 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