JTR Speakers Growler (2015) vs WW Speaker Cabinets X21 - B&C 21DS115-4

Last updated: August 9, 2026

Short answer: the WW Speaker Cabinets X21 - B&C 21DS115-4 for the higher ranking, the JTR Speakers Growler (2015) for the lower price. The WW Speaker Cabinets X21 - B&C 21DS115-4 ranks #1 of 7 subwoofers at $3995. The JTR Speakers Growler (2015) ranks #2 at $2995, $1000 cheaper.

The case for the JTR Speakers Growler (2015): 12-inch ported driver reaches 130.2dB CEA-2010-A average, nearly matching the class leader for about $1,000 less. The tradeoff: Ported design room interaction, 45 kg size, and $2,995 cost.

What the WW Speaker Cabinets X21 - B&C 21DS115-4 gets right: 21-inch driver in a large ported cabinet delivers 131.3dB CEA-2010-A average, the highest output of any passive subwoofer tested. The catch: Premium $3,995 price, massive 52 kg cabinet, and ported room gain dependency.

Buy the JTR Speakers Growler (2015) if the price matters more than the ranking. Buy the WW Speaker Cabinets X21 - B&C 21DS115-4 if the ranking matters more than the price.

Specifications Side By Side

JTR Speakers Growler (2015) WW Speaker Cabinets X21 - B&C 21DS115-4
Price$2995$3995
Ranked#2 of 7 in Large Passive Home Subwoofers (Over 75 lbs)#1 of 7 in Large Passive Home Subwoofers (Over 75 lbs)
Enclosureported, frontported, front
PassiveYesYes
Output SPL at 20 Hz92.8 dB121.9 dB
Output SPL at 25 Hz97.2 dB120.8 dB
Output SPL at 31.5 Hz106.6 dB122.5 dB
Output SPL at 40 Hz122.7 dB126.7 dB
Output SPL at 50 Hz130.0 dB129.2 dB
Output SPL at 63 Hz133.6 dB132.9 dB
Output SPL at 80 Hz134.4 dB136.3 dB
Output SPL at 100 Hz135.5 dB139.0 dB
Output SPL at 125 Hz136.0 dB140.1 dB
CEA-2010-A Average (40-80Hz)130.2 dB131.3 dB
Dimensions22.5"H x 30.0"W x 20.0"D (571.5 x 762.0 x 508.0 mm)24.0"H x 32.0"W x 32.0"D (609.6 x 812.8 x 812.8 mm)
CountryUnited States-
Measurement SourceData-bassData-bass
Weight100.1 lbs / 45.4 kg115.1 lbs / 52.2 kg
Drivers12" (305mm) driver21" (533mm) driver
Output SPL at 12.5 Hz-96.2 dB
Output SPL at 15 Hz-111.9 dB

The Two Speakers In Full

JTR Speakers Growler (2015): $2995

JTR Speakers Growler (2015) ranking card

Pros: 12-inch ported driver reaches 130.2dB CEA-2010-A average, nearly matching the class leader for about $1,000 less.

Cons: Ported design room interaction, 45 kg size, and $2,995 cost.

Notes: Looks like “PA sub”

CEA-2010-A Average (40-80Hz)130.2 dB
CountryUnited States
Dimensions22.5"H x 30.0"W x 20.0"D (571.5 x 762.0 x 508.0 mm)
Drivers12" (305mm) driver
Enclosureported, front
Measurement SourceData-bass
Output SPL at 20 Hz92.8 dB
Output SPL at 25 Hz97.2 dB
Output SPL at 31.5 Hz106.6 dB
Output SPL at 40 Hz122.7 dB
Output SPL at 50 Hz130.0 dB
Output SPL at 63 Hz133.6 dB
Output SPL at 80 Hz134.4 dB
Output SPL at 100 Hz135.5 dB
Output SPL at 125 Hz136.0 dB
PassiveYes
Weight100.1 lbs / 45.4 kg

WW Speaker Cabinets X21 - B&C 21DS115-4: $3995

WW Speaker Cabinets X21 - B&C 21DS115-4 ranking card

Pros: 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 $3,995 price, massive 52 kg cabinet, and ported room gain dependency.

CEA-2010-A Average (40-80Hz)131.3 dB
Dimensions24.0"H x 32.0"W x 32.0"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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Product prices and availability were last checked August 9, 2026 at 6:57 AM UTC 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.