Short answer: the WW Speaker Cabinets X21 - B&C 21DS115-4 for better sound quality, the HSU Research VTF-3 MK5 HP for the lower price. The WW Speaker Cabinets X21 - B&C 21DS115-4 ranks #3 of 143 subwoofers, rated 4.6/5, at $3,995. The HSU Research VTF-3 MK5 HP ranks #59, rated 4.2/5, at $1,049, $2,946 cheaper.
What the HSU Research VTF-3 MK5 HP does well: A 15 inch ported subwoofer with excellent output for the money, a strong value pick for movies and music. The catch: Ported design requires careful room placement, mid-size 86 lbs (39 kg) cabinet, and mid-range output.
The WW Speaker Cabinets X21 - B&C 21DS115-4 is the better-sounding option. A passive 21 inch ported subwoofer with enormous output, made for big home theater rooms. Watch for: Premium $3995 price, massive 114.6 lbs (52 kg) cabinet, and ported room gain dependency.
Buy the HSU Research VTF-3 MK5 HP if the price is the priority over sound quality, or the WW Speaker Cabinets X21 - B&C 21DS115-4 if sound quality is the priority over the price.
Still deciding? The full Subwoofers rankings cover every ranked option.
A 15 inch ported subwoofer with excellent output for the money, a strong value pick for movies and music.
A passive 21 inch ported subwoofer with enormous output, made for big home theater rooms.
Prices on this page were last checked October 29, 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
| HSU Research VTF-3 MK5 HP | WW Speaker Cabinets X21 - B&C 21DS115-4 | |
|---|---|---|
| Price | $1,049.00 | $3,995 Passive |
| Ranked | #59 of 143 in Large Home Subwoofers (Over 75 lbs) | #3 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 15 Hz | 100.8 dB | 111.9 dB |
| Output SPL at 20 Hz | 108.2 dB | 121.9 dB |
| Output SPL at 25 Hz | 113.4 dB | 120.8 dB |
| Output SPL at 31.5 Hz | 118.2 dB | 122.5 dB |
| Output SPL at 40 Hz | 121.9 dB | 126.7 dB |
| Output SPL at 50 Hz | 122.3 dB | 129.2 dB |
| Output SPL at 63 Hz | 121.1 dB | 132.9 dB |
| Output SPL at 80 Hz | 120.4 dB | 136.3 dB |
| CEA-2010-A Average (40-80Hz) | 121.4 dB | 131.3 dB |
| Dimensions | 25”H x 17.2”W x 24”D (635.0 x 438.1 x 609.6 mm) | 24”H x 32”W x 32”D (609.6 x 812.8 x 812.8 mm) |
| Weight | 85.1 lbs (38.6 kg) | 115.1 lbs (52.2 kg) |
| Warranty | 7/2(+3) | - |
| Cabinet Color | black | - |
| Country | United States | United States |
| Measurement Source | Manufacturer | Data-bass |
| Drivers | 15” (381mm) driver | 21” (533mm) driver |
| Passive | - | Yes |
| Output SPL at 12.5 Hz | - | 96.2 dB |
| Output SPL at 100 Hz | - | 139.0 dB |
| Output SPL at 125 Hz | - | 140.1 dB |
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