JBL MTC-300BB8 Backbox For 8" Control 300 Series Drivers B-Stock
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- MTC-300BB8-B
Description
JBL MTC-300BB8 Backbox For 8" Control 300 Series Drivers B-Stock
The MTC-300BB8 is a professional-grade enclosure engineered for in-ceiling speaker installations in venues, installations, and commercial spaces. Built to mount flush with suspended ceilings, this backbox provides the acoustic foundation and structural integrity needed to support consistent performance from JBL's 8-inch Control 300 drivers in touring rigs, fixed installations, and sound reinforcement systems.
Construction & Acoustic Design
Built from 16 gauge metal with 12 mm MDF lining, this backbox eliminates resonances and delivers extended bass response from a compact footprint. The interior volume of 0.71 cubic feet is precisely engineered to complement the 8-inch driver's performance characteristics, allowing you to get full-range output without requiring excessive ceiling cavity space or additional bracing.
Installation & Compliance
The 310 mm (12.2 in) ceiling cutout integrates seamlessly into standard drop-ceiling grids, while five knockout locations (one on top, four on sides) accommodate various cable routing configurations for fast setup and changes. Full certification under U.L.-2043, U.L.-1480, NFPA90, and NFPA70A ensures safe operation in air-handling plenums and other regulated spaces, protecting your investment and guaranteeing code compliance on every install.
Key Features
- Extra-thick 16 gauge metal construction for durability and vibration control
- 12 mm (½ inch) thick MDF lining to eliminate resonances and extend bass response
- External volume: 1.0 cubic foot nominal
- Internal volume: 0.71 cubic foot
- Outside diameter: 380 mm (15.0 inches)
- Inside diameter: 273 mm (10.7 inches)
- Height: 259 mm (10.2 inches) above ceiling / 268 mm (10.6 inches) total height
- Ceiling cutout size: 310 mm (12.2 inches)
- Five knockout locations: 22.1 mm (0.87 inch) diameter openings for flexible wiring
- Net weight: 5.2 kg (11.5 lbs) / Shipping weight: 7.9 kg (16.5 lbs)
- U.L.-2043, U.L.-1480, NFPA90, and NFPA70A certified for air handling spaces
- Designed specifically for JBL 8-inch Control 300 series drivers
The MTC-300BB8 delivers the rigorous engineering and compliance standards required for professional sound systems where acoustic performance, road reliability, and code adherence are non-negotiable.
More Information
| Condition | Refurbished |
|---|---|
| Country of Manufacture | China |
Reviews
About this B-Stock unit
| Condition | Factory B-Stock direct from the manufacturer: open box, show or demo unit, or a minor cosmetic blemish. Fully tested. |
|---|---|
| Warranty | FULL manufacturer warranty, the same as a new unit |
| Ships from | The manufacturer's US warehouse, about 2 business days handling, tracking emailed when it leaves |
| Price vs new | $37 under the new unit ($173) |
Prefer a brand-new one? JBL MTC-300BB8 Backbox For 8" Control 300 Series Drivers is in the catalog at $173.
At a Glance
The JBL MTC-300BB8 is a professional in-ceiling backbox enclosure built to mount flush with drop ceilings and house 8-inch Control 300 series drivers in commercial and institutional spaces. Live-sound installers and systems integrators rely on it for conference rooms, venues, and permanent installations where code compliance and acoustic control matter—its 16-gauge metal and MDF lining eliminate resonances and extend bass response from a compact footprint. Choose it when you need U.L. and NFPA certification, trouble-free ceiling integration, and the foundation to deliver consistent speech clarity and audio performance in mission-critical environments.
Who This Is For
| Best suited for | commercial installations, institutional audio, in-ceiling speaker systems, conference rooms |
|---|---|
| Tonal character | Extended bass response, resonance-free, controlled midrange, vibration-isolated |
| Less specialized for | home audio, portable applications, outdoor use (it will do it; instruments voiced for that style do it more easily) |
| Skill level | Professional |
Frequently Asked Questions
What does B-Stock mean for this backbox?
B-Stock means the MTC-300BB8 is fully functional and acoustically identical to new, but may have minor cosmetic imperfections such as small dents, scratches, or finish marks on the metal exterior. All acoustic and structural performance is unaffected.
Is this backbox compatible with any 8-inch speaker, or only JBL Control 300 drivers?
The MTC-300BB8 is specifically engineered for JBL's 8-inch Control 300 series drivers. Its internal volume of 0.71 cubic feet and acoustic tuning are optimized for those drivers, so using it with other brands or sizes may not deliver the intended performance.
What certifications does this backbox hold?
The MTC-300BB8 is fully certified under U.L.-2043, U.L.-1480, NFPA90, and NFPA70A, making it safe for use in air-handling plenums and other regulated commercial and institutional spaces.
How does the MDF lining affect acoustic performance?
The 12 mm MDF lining absorbs internal reflections and standing waves, eliminating resonances and extending bass response. Combined with the 16-gauge metal shell, it provides vibration isolation and acoustic control critical for clean speech and music reproduction in ceiling-mounted applications.
Does this backbox fit standard drop-ceiling grids?
Yes—the 310 mm (12.2 inch) ceiling cutout integrates seamlessly into standard drop-ceiling grids. Five knockout locations (one on top, four on sides) allow flexible cable routing for various installation configurations.
Do I pay sales tax on this order?
Sales tax is collected only on orders shipped to California; orders shipped to any other US state are not charged sales tax at checkout when you buy direct from our website. Marketplaces collect sales tax as the facilitator in most states, so the same listed price can cost more there. Buyers remain responsible for any use tax their state applies. Free US shipping and 30-day returns are included.
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