B&C 15BG76 – Essential 15-Inch Neodymium Subwoofer Driver for Deep Low-Frequency Output

The B&C 15BG76 is the only dedicated long-throw subwoofer driver in B&C’s neodymium 15-inch range — and it approaches the format from a completely different angle than every other neo 15 in the lineup. Where B&C’s woofer-class neo 15s chase sensitivity with light cones and exponential profiles, the B&C 15BG76 chases displacement. A 9.6 mm Xmax, 12.5 mm Xvar, 194 g moving mass, rubber roll surround, and radial cone define a driver built to move air in the sub-bass region — not to win efficiency contests.

With a Qts of 0.56 and an EBP of 72 Hz, the B&C 15BG76 is one of the few drivers in B&C’s range that genuinely works in a sealed enclosure. It’s equally at home in a vented box tuned low — B&C recommends 160 litres tuned to 34 Hz — but that high Qts gives builders the sealed-box option that B&C’s lower-Qts woofers simply can’t support without sounding thin and over-damped.

At 5.95 kg with an FEA-optimised neodymium ring magnet, aluminium demodulating ring, ventilated gap, woven lead wires, and double silicone spider, the B&C 15BG76 carries a premium feature set that keeps distortion low and output consistent even at the high excursion levels this driver is designed to operate at routinely.

Design and Construction of the B&C 15BG76

The B&C 15BG76 uses a 76 mm (3-inch) copper voice coil wound on a glass fibre former. The 25 mm winding depth — the deepest of any 76 mm coil 15-inch driver B&C makes — operating in an 11.5 mm magnetic gap yields 9.6 mm of linear one-way excursion (Xmax) with an additional 12.5 mm of travel (Xvar) before mechanical limits. That 22.1 mm total one-way excursion before damage is exceptional for a 15-inch driver with a 3-inch coil, and the woven lead wires through the spider are designed to survive these displacement levels over the long term.

The motor uses an FEA-optimised neodymium ring magnet in a T-pole configuration, producing 1.22 T of flux density and a force factor (Bl) of 21.7 Tm. The ring magnet topology provides uniform flux distribution across the voice coil gap, and the FEA optimisation ensures that every gram of neodymium is working at maximum efficiency. An aluminium demodulating ring reduces flux modulation, keeping harmonic and intermodulation distortion controlled as the driver operates at high excursion levels — a critical feature for a sub driver that spends most of its life at or near full Xmax.

The surround is a rubber roll — not the triple-roll design found on B&C’s woofer-class 15s. The rubber roll surround provides the high compliance and large stroke capability that long-throw sub-bass operation demands. The radial cone profile is tuned for low-frequency piston behaviour rather than upper-frequency extension, which is why the B&C 15BG76’s bandwidth stops at 1000 Hz instead of the 2000–3000 Hz typical of B&C’s woofer-class 15s.

A ventilated voice coil gap reduces power compression during sustained use. Suspension is handled by a double silicone spider with optimised compliance. TWP waterproof treatment on both sides of the cone provides full weather resistance. At 5.95 kg and 190 mm deep, the B&C 15BG76 is remarkably light for a neo sub driver with this much excursion capability. The 23 mm flange thickness — the thickest of any 15-inch driver in B&C’s range — reflects the deeper motor assembly required for the long-throw voice coil geometry.

Performance and Applications for the B&C 15BG76

The B&C 15BG76 delivers 93.4 dB sensitivity and 0.93% reference efficiency across a 44 Hz – 1000 Hz bandwidth. Those numbers are deliberately low compared to B&C’s woofer-class neo 15s — and that’s the point. The sensitivity has been traded for displacement. The heavier 194 g moving mass, deeper winding, and high-compliance surround all sacrifice efficiency to gain the 9.6 mm of linear excursion and deep low-frequency reach that the woofer-class drivers can’t provide.

The Thiele–Small parameters define a fundamentally different driver from everything else in B&C’s neo 15-inch range. A Qts of 0.56 and an EBP of 72 Hz place the B&C 15BG76 in sealed or low-tuned vented enclosure territory — the exact opposite of the low-Qts, high-EBP woofers that dominate the rest of the lineup. That high Qts means this driver produces a naturally flat, well-extended bass response in a sealed box without EQ assistance, something no other neo 15 in B&C’s range can do.

B&C recommends a 160-litre (5.65 ft³) vented enclosure tuned to 34 Hz — the deepest tuning recommendation of any 15-inch driver in B&C’s range. That 34 Hz tuning, combined with the 9.6 mm Xmax and 855 cm² radiating area, gives the B&C 15BG76 genuine sub-bass output capability that approaches some lightly loaded 18-inch drivers. For sealed alignments, expect good results in the 60–100 litre range with a naturally rolled-off response below 50–60 Hz that many applications find musically pleasing.

Ideal applications for the B&C 15BG76 include:

• Compact 15-inch subwoofer cabinets for portable PA and DJ systems
• Sealed sub enclosures where a high Qts provides naturally flat bass response
• Vented sub designs tuned low for genuine sub-bass extension
• Lightweight sub cabinets where neodymium weight savings matter
• DIY builds requiring a true sub driver — not a woofer repurposed for sub duties

Specifications – B&C 15BG76

• Nominal Diameter: 380 mm (15 in)
• Nominal Impedance: 8 Ω
• Minimum Impedance: 6.5 Ω
• Nominal Power Handling: 500 W
• Continuous Power Handling: 1000 W
• Sensitivity: 93.4 dB
• Frequency Range: 44 Hz – 1000 Hz
• Voice Coil Diameter: 76 mm (3 in)
• Winding Material: Copper
• Former Material: Glass Fibre
• Winding Depth: 25 mm (0.98 in)
• Magnetic Gap Depth: 11.5 mm (0.45 in)
• Flux Density: 1.22 T
• Magnet Material: Neodymium Ring
• Cone Shape: Radial
• Cone Treatment: TWP Waterproof (both sides)
• Surround Shape: Roll
• Spider: Double Silicone
• Pole Design: T-Pole
• Net Weight: 5.95 kg (13.12 lb)

Thiele–Small Parameters – B&C 15BG76

• Fs: 44 Hz
• Re: 5.4 Ω
• Qes: 0.61
• Qms: 6.2
• Qts: 0.56
• Vas: 68.4 dm³ (2.42 ft³)
• Sd: 855 cm² (132.53 in²)
• η0: 0.93%
• Xmax: 9.6 mm
• Xvar: 12.5 mm
• Mms: 194 g
• Bl: 21.7 Tm
• Le: 1.29 mH
• EBP: 72 Hz

Mounting Information – B&C 15BG76

• Overall Diameter: 393 mm (15.47 in)
• Bolt Circle Diameter: 374 mm (14.7 in)
• Baffle Cutout Diameter: 354 mm (13.9 in)
• Depth: 190 mm (7.48 in)
• Flange and Gasket Thickness: 23 mm (0.91 in)
• Air Volume Occupied by Driver: 6 dm³ (0.21 ft³)
• Recommended Enclosure Volume: 160 dm³ (5.65 ft³)
• Recommended Tuning Frequency: 34 Hz

Conclusion – B&C 15BG76 Subwoofer Driver

The B&C 15BG76 is the only neo 15-inch driver in B&C’s range designed from the ground up as a dedicated subwoofer. Everything about it is optimised for displacement and deep bass — the long-throw voice coil, the high-compliance rubber surround, the radial cone, the heavy moving mass, and the high Qts that supports sealed enclosure operation. It doesn’t pretend to be a woofer that can also do sub duties. It is a sub driver, and it behaves like one.

The premium feature set — FEA-optimised neo ring magnet, demodulating ring, woven leads, ventilated gap, double spider — ensures that the high-excursion operation this driver is built for stays clean and controlled. At 5.95 kg, it keeps the neodymium weight advantage while delivering displacement capability that approaches some ferrite 18-inch subs. The 34 Hz recommended tuning is the deepest of any 15-inch driver B&C makes.

For builders who need a true 15-inch sub — not a repurposed mid-bass woofer, but a dedicated long-throw sub driver that reaches down into the low end and stays there — the B&C 15BG76 is the neodymium 15-inch that fills the role. Sealed or vented, it delivers the deep, controlled bass that only a purpose-built sub driver can provide.

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About B&C Speakers S.r.L.

B&C Speakers products are built in Bagno a Ripoli (Florence), Italy., ensuring high quality products to suite your speaker building requirements. Their 10,500 square meter facility incorporates highly sophisticated automation and quality control. Over the years they become one of the world leaders in the Professional Audio market, a brand recognized everywhere as a premium product that offers excellent value to the consumer.