Short answer: the Monoprice Monolith 16 THX Ultra for better sound quality, the SVS SB13-Plus for the lower price. The Monoprice Monolith 16 THX Ultra ranks #18 of 110 subwoofers at $2300. The SVS SB13-Plus ranks #108 at $1399, $901 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 SVS SB13-Plus offers: Independent CEA-2010 testing records 92.3 dB at 20 Hz and 108.1 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 13” (330mm) 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 431.8H x 431.8W x 457.2D mm cabinet and 43.1 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 SVS SB13-Plus when the price outweighs sound quality instead.
The SVS SB13-Plus is not a sound-quality pick. It sits near the bottom of the 110 subwoofers; there are better options higher up.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | SVS SB13-Plus | |
|---|---|---|
| Price | $2,300 | $1399 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #108 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 | 92.3 dB |
| Output SPL at 25 Hz | 123.3 dB | 97.2 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 97.2 dB |
| Output SPL at 40 Hz | 126.3 dB | 108.1 dB |
| Output SPL at 50 Hz | 126.5 dB | 108.1 dB |
| Output SPL at 63 Hz | 126.6 dB | 108.1 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 | 108.1 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) | 17"H x 17"W x 18"D (431.8 x 431.8 x 457.2 mm) |
| Weight | 171.5 lbs (77.8 kg) | 95 lbs (43.1 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | - |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 16" (406mm) driver | 13" (330mm) driver |
Related Speaker Comparisons
How Monoprice Monolith 16 THX Ultra compares with other leading options:
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- 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
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
- Monoprice Monolith 16 THX Ultra vs Harbottle Audio C24 L2
- 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
SVS SB13-Plus: $1399 eBay
Pros: Independent CEA-2010 testing records 92.3 dB at 20 Hz and 108.1 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 13” (330mm) 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 431.8H x 431.8W x 457.2D mm cabinet and 43.1 kg mass still require deliberate placement and calibration.
Full SVS SB13-Plus review and specifications →
| CEA-2010-A Average (40-80Hz) | 108.1 dB (avg of 3/4 bands) |
|---|---|
| Country | United States |
| Dimensions | 17"H x 17"W x 18"D (431.8 x 431.8 x 457.2 mm) |
| Drivers | 13" (330mm) driver |
| Enclosure | sealed |
| Measurement Source | Brent Butterworth |
| Output SPL at 20 Hz | 92.3 dB |
| Output SPL at 25 Hz | 97.2 dB |
| Output SPL at 31.5 Hz | 97.2 dB |
| Output SPL at 40 Hz | 108.1 dB |
| Output SPL at 50 Hz | 108.1 dB |
| Output SPL at 63 Hz | 108.1 dB |
| Warranty | 5 |
| Weight | 95 lbs (43.1 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