Short answer: the Harbinger V2218S for better sound quality, the Monoprice Monolith 16 THX Ultra for the lower price. The Harbinger V2218S ranks #15 of 110 subwoofers at $3495. The Monoprice Monolith 16 THX Ultra ranks #18 at $2300, $1195 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 Harbinger V2218S offers: Independent CEA-2010 testing records 81.7 dB at 20 Hz and 128.9 dB through 40-80 Hz. The ported, front enclosure with 18” (457mm) driver delivers formidable 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 825.5H x 673.1W x 754.4D mm cabinet and 40.8 kg mass still require deliberate placement and calibration.
Buy the Monoprice Monolith 16 THX Ultra if the price is the priority over sound quality, or the Harbinger V2218S if sound quality is the priority over the price.
Want more options? Browse the full Subwoofers rankings.
Specifications Side By Side
| Monoprice Monolith 16 THX Ultra | Harbinger V2218S | |
|---|---|---|
| Price | $2,300 | $3495 |
| Ranked | #18 of 110 in Large Home Subwoofers (Over 75 lbs) | #15 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 | 81.7 dB |
| Output SPL at 25 Hz | 123.3 dB | 99.7 dB |
| Output SPL at 31.5 Hz | 125.1 dB | 118.0 dB |
| Output SPL at 40 Hz | 126.3 dB | 122.8 dB |
| Output SPL at 50 Hz | 126.5 dB | 129.0 dB |
| Output SPL at 63 Hz | 126.6 dB | 132.2 dB |
| Output SPL at 80 Hz | 126.8 dB | 131.7 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 | 128.9 dB |
| Dimensions | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) | 32.5"H x 26.5"W x 29.7"D (825.5 x 673.1 x 754.4 mm) |
| Weight | 171.5 lbs (77.8 kg) | 89.9 lbs (40.8 kg) |
| Warranty | 5 | - |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Brent Butterworth |
| Drivers | 16" (406mm) driver | 18" (457mm) driver |
Related Speaker Comparisons
How Harbinger V2218S compares with other leading options:
- Harbinger V2218S vs JTR Speakers Captivator 2400ULF
- Monoprice Monolith 16 THX Ultra vs JTR Speakers Captivator 215PRO
- JTR Speakers Captivator 2400 vs Monoprice Monolith 16 THX Ultra
- Monoprice Monolith 16 THX Ultra vs JTR Speakers Captivator 2400ULF
- Monoprice Monolith 16 THX Ultra vs Arendal 1723 Subwoofer 2V
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 Danley Sound Labs DTS10
- Monoprice Monolith 16 THX Ultra vs Rythmik FV25HP
- Monoprice Monolith 16 THX Ultra vs Monoprice Monolith M-215
- See all 54 comparisons
Harbinger V2218S: $3495 eBay
Pros: Independent CEA-2010 testing records 81.7 dB at 20 Hz and 128.9 dB through 40-80 Hz. The ported, front enclosure with 18” (457mm) driver delivers formidable 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 825.5H x 673.1W x 754.4D mm cabinet and 40.8 kg mass still require deliberate placement and calibration.
Notes: Looks like “PA sub”
Full Harbinger V2218S review and specifications →
| CEA-2010-A Average (40-80Hz) | 128.9 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 32.5"H x 26.5"W x 29.7"D (825.5 x 673.1 x 754.4 mm) |
| Drivers | 18" (457mm) driver |
| Enclosure | ported, front |
| Measurement Source | Brent Butterworth |
| Output SPL at 20 Hz | 81.7 dB |
| Output SPL at 25 Hz | 99.7 dB |
| Output SPL at 31.5 Hz | 118.0 dB |
| Output SPL at 40 Hz | 122.8 dB |
| Output SPL at 50 Hz | 129.0 dB |
| Output SPL at 63 Hz | 132.2 dB |
| Output SPL at 80 Hz | 131.7 dB |
| Weight | 89.9 lbs (40.8 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