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JBL's MTC-300BB8 One-Cubic-Foot Backbox features extra-thick 16-gauge metal construction and a thick resonance-eliminating lining that also provides extra bass response. Made for the Control 328C and 328CT 8" Drivers, this backbox has knockouts on the sides and top panel.



  • Extra-thick 16 gauge metal construction.
  • Lined with 12 mm (½ inch) thick MDF to eliminate resonances and to provide extra bass response.
  • Knockouts on top and side.

JBL MTC-300BB8 One Cubic Foot Back Box for 8" Models

  • External Volume 1 cu ft., nominal
    Internal Volume .71 cu ft.
    Knockouts 22.1 mm (0.87 in) diameter opening
    Five (5) locations: 
    1 on top panel
    4 on side of can
    Height 259 mm (10.2 in) above ceiling
    268 mm (10.6 in) total height
    Outside Diameter 380 mm (15.0 in)
    Inside Diameter 273 mm (10.7 in)
    Ceiling Cut Out 310 mm (12.2 in)
    Safety Agency Rating Suitable for use in air handling spaces, per
    U.L.-2043, U.L.-1480, NFPA90 & NFPA70A
    Net Weight 5.2 kg (11.5 lbs)
    Shipping Weight 7.9 kg (16.5 lbs)
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