Short answer: the Funk Audio Classic 21.0L. Both are rated 4.2/5 for sound quality (#48 and #47 of 143 subwoofers), and the Funk Audio Classic 21.0L costs $2,995 against $3,600 for the JTR Speakers Captivator 2400ULF, so with nothing between them on sound quality, price settles it.
Why pick the Funk Audio Classic 21.0L: A sealed 21 inch subwoofer with deep, powerful bass for large rooms, relatively affordable for its size. The catch: The 800.1H x 660.4W x 609.6D mm cabinet and 155 lbs (70.3 kg) mass make this a serious placement and moving commitment.
Why pick the JTR Speakers Captivator 2400ULF: A tall 18 inch ported subwoofer tuned for very low bass, with strong output for large home theaters. Watch for: The 1041.4H x 520.7W x 571.5D mm cabinet and 164.9 lbs (74.8 kg) mass make this a serious placement and moving commitment.
Buy the Funk Audio Classic 21.0L. Both are rated the same for sound quality, and it costs $605 less than the JTR Speakers Captivator 2400ULF.
Still deciding? The full Subwoofers rankings cover every ranked option.
A sealed 21 inch subwoofer with deep, powerful bass for large rooms, relatively affordable for its size.
A tall 18 inch ported subwoofer tuned for very low bass, with strong output for large home theaters.
Prices on this page were last checked October 24, 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.
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Specifications Side By Side
| Funk Audio Classic 21.0L | JTR Speakers Captivator 2400ULF | |
|---|---|---|
| Price | $2,995 | $3,600 |
| Ranked | #48 of 143 in Large Home Subwoofers (Over 75 lbs) | #47 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | ported, front |
| Output SPL at 10 Hz | 99.0 dB | 104.8 dB |
| Output SPL at 12.5 Hz | 102.0 dB | 109.0 dB |
| Output SPL at 15 Hz | 108.0 dB | 112.2 dB |
| Output SPL at 20 Hz | 114.0 dB | 115.6 dB |
| Output SPL at 25 Hz | 118.5 dB | 117.9 dB |
| Output SPL at 31.5 Hz | 122.0 dB | 121.8 dB |
| Output SPL at 40 Hz | 122.4 dB | 123.3 dB |
| Output SPL at 50 Hz | 123.3 dB | 123.3 dB |
| Output SPL at 63 Hz | 122.5 dB | 122.4 dB |
| Output SPL at 80 Hz | 122.0 dB | 121.6 dB |
| Output SPL at 100 Hz | 122.5 dB | 121.3 dB |
| CEA-2010-A Average (40-80Hz) | 122.5 dB | 122.7 dB |
| Dimensions | 31.5”H x 26”W x 24”D (800.1 x 660.4 x 609.6 mm) | 41”H x 20.5”W x 22.5”D (1041.4 x 520.7 x 571.5 mm) |
| Weight | 155 lbs (70.3 kg) | 164.9 lbs (74.8 kg) |
| Warranty | 3 | 5/3 |
| Cabinet Color | wood, custom | black, custom |
| Country | Canada | United States |
| Measurement Source | Manufacturer | Data-bass |
| Drivers | 21” (533mm) driver | 18” (457mm) driver |
| Inputs | XLR (balanced) | XLR, RCA |
| XLR Input | Yes | Yes |
| RCA Input | No | 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 |
| Output SPL at 125 Hz | - | 121.4 dB |
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