Short answer: the XTZ Sound SUB 3X12, if you are buying new. The Monoprice Monolith 16 THX Ultra ranks higher than it (#19 vs #28 of 143 subwoofers, 4.4/5 vs 4.3/5) but is discontinued, so only consider it used; the XTZ Sound SUB 3X12 is still sold new at $1,412.84.
Why pick the Monoprice Monolith 16 THX Ultra: A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used. The tradeoff: Heavy at 172 lbs (78 kg) and ported design can interact with room acoustics.
What the XTZ Sound SUB 3X12 does well: A triple 12 inch subwoofer with huge, deep output for movies in a large room, for less than most rivals. The catch: The 1158.2H x 535.9W x 556.3D mm cabinet and 170.6 lbs (77.4 kg) mass make this a serious placement and moving commitment.
Buy the XTZ Sound SUB 3X12 if you want one new; the Monoprice Monolith 16 THX Ultra is discontinued, so only look for it used.
Looking for alternatives? See the complete Subwoofers rankings.
A THX Ultra certified 16 inch ported subwoofer with huge output for far less money than most rivals, now worth finding used.
A triple 12 inch subwoofer with huge, deep output for movies in a large room, for less than most rivals.
Prices on this page were last checked October 29, 2026 at 4:42 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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | XTZ Sound SUB 3X12 | |
|---|---|---|
| Price | $2,300 Discontinued | $1,412.84 |
| Ranked | #19 of 143 in Large Home Subwoofers (Over 75 lbs) | #28 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 107.3 dB | 109.1 dB |
| Output SPL at 20 Hz | 118.4 dB | 114.5 dB |
| Output SPL at 25 Hz | 123.3 dB | 118.5 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 121.8 dB |
| Output SPL at 40 Hz | 126.3 dB | 124.8 dB |
| Output SPL at 50 Hz | 126.5 dB | 125.4 dB |
| Output SPL at 63 Hz | 126.6 dB | 125.4 dB |
| Output SPL at 80 Hz | 126.8 dB | 125.6 dB |
| Output SPL at 100 Hz | 127.2 dB | 126.1 dB |
| Output SPL at 125 Hz | 127.6 dB | 126.4 dB |
| CEA-2010-A Average (40-80Hz) | 126.5 dB | 125.3 dB |
| Dimensions | 25.6”H x 22”W x 28.1”D (650.2 x 558.8 x 713.7 mm) | 45.6”H x 21.1”W x 21.9”D (1158.2 x 535.9 x 556.3 mm) |
| Weight | 171.5 lbs (77.8 kg) | 170.6 lbs (77.4 kg) |
| Warranty | 5 | 5/2 |
| Cabinet Color | black | black |
| Country | United States | Sweden |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 16” (406mm) driver | 3x 12” (305mm) drivers |
| Inputs | XLR, RCA, XLR 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 | - |
| Output SPL at 12.5 Hz | - | 100.0 dB |
Related Speaker Comparisons
More worthwhile head-to-heads for Monoprice Monolith 16 THX Ultra:
- JTR Speakers Orbit Shifter PRO vs Monoprice Monolith 16 THX Ultra
- JTR Speakers Orbit Shifter LFU vs Monoprice Monolith 16 THX Ultra
- Monoprice Monolith 16 THX Ultra vs WW Speaker Cabinets X21 - B&C 21DS115-4
- Monoprice Monolith 16 THX Ultra vs Pro Audio Technology LFC-24sm
- Monoprice Monolith 16 THX Ultra vs Power Sound Audio (PSA) TRIAX