Short answer: the Power Sound Audio (PSA) T18 if sound quality matters most, the Monoprice Monolith 16 THX Ultra if price matters most. The Power Sound Audio (PSA) T18 ranks #8 of 110 subwoofers at $4995. The Monoprice Monolith 16 THX Ultra ranks #18 at $2300, $2695 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 Power Sound Audio (PSA) T18 offers: Published CEA-2010 specifications list 115.7 dB at 20 Hz and 129.7 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room. Watch for: The 596.9H x 787.4W x 698.5D mm cabinet and 77.1 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Buy the Monoprice Monolith 16 THX Ultra if the price is the priority over sound quality, or the Power Sound Audio (PSA) T18 if sound quality is the priority over the price.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | Power Sound Audio (PSA) T18 | |
|---|---|---|
| Price | $2,300 | $4995 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #8 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | sealed |
| Output SPL at 15 Hz | 107.3 dB | - |
| Output SPL at 20 Hz | 118.4 dB | 115.7 dB |
| Output SPL at 25 Hz | 123.3 dB | 115.7 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 115.7 dB |
| Output SPL at 40 Hz | 126.3 dB | 129.7 dB |
| Output SPL at 50 Hz | 126.5 dB | 129.7 dB |
| Output SPL at 63 Hz | 126.6 dB | 129.7 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 | 129.7 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) | 23.5"H x 31"W x 27.5"D (596.9 x 787.4 x 698.5 mm) |
| Weight | 171.5 lbs (77.8 kg) | 170 lbs (77.1 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | - |
| Country | United States | United States |
| Measurement Source | Audioholics | Manufacturer |
| Drivers | 16" (406mm) driver | 18" (457mm) driver |
Related Speaker Comparisons
How Power Sound Audio (PSA) T18 compares with other leading options:
- JTR Speakers Captivator 4000ULF vs Power Sound Audio (PSA) T18
- JTR Speakers Captivator 215PRO vs Power Sound Audio (PSA) T18
- JTR Speakers Captivator S2 vs Power Sound Audio (PSA) T18
- Power Sound Audio (PSA) T18 vs Power Sound Audio (PSA) V3600I
- Monoprice Monolith 16 THX Ultra vs Genelec 7070A
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.
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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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- Monoprice Monolith 16 THX Ultra vs Funk Audio Ultra 21.0LX
- Monoprice Monolith 16 THX Ultra vs Funk Audio Classic 18.0
- Monoprice Monolith 16 THX Ultra vs JTR Speakers Captivator 2400
- Monoprice Monolith 16 THX Ultra vs Reaction Audio PV-15X
- Monoprice Monolith 16 THX Ultra vs Harbinger V2218S
- Monoprice Monolith 16 THX Ultra vs Danley Sound Labs DTS10
- Monoprice Monolith 16 THX Ultra vs Rythmik FV25HP
- See all 54 comparisons
Power Sound Audio (PSA) T18: $4995 eBay
Pros: Published CEA-2010 specifications list 115.7 dB at 20 Hz and 129.7 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room.
Cons: The 596.9H x 787.4W x 698.5D mm cabinet and 77.1 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Full Power Sound Audio (PSA) T18 review and specifications →
| CEA-2010-A Average (40-80Hz) | 129.7 dB (avg of 3/4 bands) |
|---|---|
| Country | United States |
| Dimensions | 23.5"H x 31"W x 27.5"D (596.9 x 787.4 x 698.5 mm) |
| Drivers | 18" (457mm) driver |
| Enclosure | sealed |
| Measurement Source | Manufacturer |
| Output SPL at 20 Hz | 115.7 dB |
| Output SPL at 25 Hz | 115.7 dB |
| Output SPL at 31.5 Hz | 115.7 dB |
| Output SPL at 40 Hz | 129.7 dB |
| Output SPL at 50 Hz | 129.7 dB |
| Output SPL at 63 Hz | 129.7 dB |
| Warranty | 5 |
| Weight | 170 lbs (77.1 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- These figures are manufacturer-specified rather than independently measured.
- Head-to-Head Comparisons