WW Speaker Cabinets X21 - B&C 21DS115-4 Review: Rated 4.6/5

Last updated: October 21, 2026

The WW Speaker Cabinets X21 - B&C 21DS115-4 is rated 4.6/5 for sound quality, #3 of 143 Large Home Subwoofers (Over 75 lbs). See all Subwoofers rankings for every top pick.

WW Speaker Cabinets X21 - B&C 21DS115-4 · Editor's rating 4.6/5, ranked #3 of 143 Large Home Subwoofers (Over 75 lbs)

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#3 WW Speaker Cabinets X21 - B&C 21DS115-4: $3,995 Passive eBay

Pros: A passive 21 inch ported subwoofer with enormous output, made for big home theater rooms. 21-inch driver in a large ported cabinet delivers 131.3dB CEA-2010-A average, the highest output of any passive subwoofer tested.

Cons: Premium $3995 price, massive 52 kg cabinet, and ported room gain dependency.

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ReleasedMar 2017 (9 years ago)
CEA-2010-A Average (40-80Hz)131.3 dB
CountryUnited States
Dimensions24”H x 32”W x 32”D (609.6 x 812.8 x 812.8 mm)
Drivers21” (533mm) driver
Enclosureported, front
Measurement SourceData-bass
Output SPL at 12.5 Hz96.2 dB
Output SPL at 15 Hz111.9 dB
Output SPL at 20 Hz121.9 dB
Output SPL at 25 Hz120.8 dB
Output SPL at 31.5 Hz122.5 dB
Output SPL at 40 Hz126.7 dB
Output SPL at 50 Hz129.2 dB
Output SPL at 63 Hz132.9 dB
Output SPL at 80 Hz136.3 dB
Output SPL at 100 Hz139.0 dB
Output SPL at 125 Hz140.1 dB
PassiveYes
Weight115.1 lbs (52.2 kg)
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