Short answer: the Monoprice Monolith 16 THX Ultra. Both are rated 4.4/5 for sound quality (#18 and #20 of 110 subwoofers), and the Monoprice Monolith 16 THX Ultra costs $2300 against $3500 for the JTR Speakers Captivator 2400, so with nothing between them on sound quality, price settles it.
The case for the Monoprice Monolith 16 THX Ultra: 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. The catch: Heavy at 78 kg (172 lbs) and ported design can interact with room acoustics.
Buy the Monoprice Monolith 16 THX Ultra. Both are rated the same for sound quality, and it costs $1200 less than the JTR Speakers Captivator 2400.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| JTR Speakers Captivator 2400 | Monoprice Monolith 16 THX Ultra | |
|---|---|---|
| Price | $3,500 | $2,300 |
| Ranked | #20 of 110 in Large Home Subwoofers (Over 75 lbs) | #18 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 10 Hz | 104.8 dB | - |
| Output SPL at 12.5 Hz | 109.1 dB | - |
| Output SPL at 15 Hz | 113.6 dB | 107.3 dB |
| Output SPL at 20 Hz | 115.5 dB | 118.4 dB |
| Output SPL at 25 Hz | 120.0 dB | 123.3 dB |
| Output SPL at 31.5 Hz | 123.3 dB | 125.1 dB |
| Output SPL at 40 Hz | 126.2 dB | 126.3 dB |
| Output SPL at 50 Hz | 126.7 dB | 126.5 dB |
| Output SPL at 63 Hz | 126.3 dB | 126.6 dB |
| Output SPL at 80 Hz | 125.8 dB | 126.8 dB |
| Output SPL at 100 Hz | 125.8 dB | 127.2 dB |
| Output SPL at 125 Hz | 124.2 dB | 127.6 dB |
| CEA-2010-A Average (40-80Hz) | 126.2 dB | 126.5 dB |
| Dimensions | 30"H x 20"W x 22.5"D (762.0 x 508.0 x 571.5 mm) | 25.6"H x 22"W x 28.1"D (650.2 x 558.8 x 713.7 mm) |
| Weight | 147.9 lbs (67.1 kg) | 171.5 lbs (77.8 kg) |
| Warranty | 5/3 | 5 |
| Cabinet Color | black, custom | black |
| Country | United States | United States |
| Measurement Source | Audioholics | Audioholics |
| Drivers | 18" (457mm) driver | 16" (406mm) driver |
| Inputs | XLR, RCA | XLR, RCA, XLR out |
| XLR Input | Yes | Yes |
| RCA Input | Yes | Yes |
| TRS Input | No | No |
| Optical Input | No | No |
| Coaxial Input | No | No |
| USB Input | No | No |
| HDMI Input | No | No |
| AES Input | No | No |
| Aux Input | No | No |
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Prices on this page were last checked September 23, 2026 at 11:24 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.
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The Two Speakers In Full
JTR Speakers Captivator 2400: $3,500 eBay
Pros: Independent CEA-2010 testing records 115.5 dB at 20 Hz and 126.2 dB through 40-80 Hz. The ported, front enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room.
Cons: The 762.0H x 508.0W x 571.5D mm cabinet and 67.1 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Full JTR Speakers Captivator 2400 review and specifications →
| AES Input | No |
|---|---|
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 126.2 dB |
| Cabinet Color | black, custom |
| Coaxial Input | No |
| Country | United States |
| Dimensions | 30"H x 20"W x 22.5"D (762.0 x 508.0 x 571.5 mm) |
| Drivers | 18" (457mm) driver |
| Enclosure | ported, front |
| HDMI Input | No |
| Inputs | XLR, RCA |
| Measurement Source | Audioholics |
| Optical Input | No |
| Output SPL at 10 Hz | 104.8 dB |
| Output SPL at 12.5 Hz | 109.1 dB |
| Output SPL at 15 Hz | 113.6 dB |
| Output SPL at 20 Hz | 115.5 dB |
| Output SPL at 25 Hz | 120.0 dB |
| Output SPL at 31.5 Hz | 123.3 dB |
| Output SPL at 40 Hz | 126.2 dB |
| Output SPL at 50 Hz | 126.7 dB |
| Output SPL at 63 Hz | 126.3 dB |
| Output SPL at 80 Hz | 125.8 dB |
| Output SPL at 100 Hz | 125.8 dB |
| Output SPL at 125 Hz | 124.2 dB |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | No |
| Warranty | 5/3 |
| Weight | 147.9 lbs (67.1 kg) |
| XLR Input | Yes |
- 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: $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 →
| AES Input | No |
|---|---|
| Aux Input | No |
| CEA-2010-A Average (40-80Hz) | 126.5 dB |
| Cabinet Color | black |
| Coaxial Input | No |
| 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 |
| HDMI Input | No |
| Inputs | XLR, RCA, XLR out |
| Measurement Source | Audioholics |
| Optical Input | No |
| 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 |
| RCA Input | Yes |
| TRS Input | No |
| USB Input | No |
| Warranty | 5 |
| Weight | 171.5 lbs (77.8 kg) |
| XLR Input | Yes |
- 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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