B&C 15NBX100 – Precision 15-Inch Neodymium Woofer with Low-Distortion High-Power Performance

The B&C 15NBX100 is B&C’s most versatile high-power neodymium 15-inch driver — a 1000 W AES woofer that pairs the thermal capacity of a 4-inch copper voice coil with an aluminium demodulating ring, ventilated gap, exponential cone, and 10 mm of linear excursion. Where the NW100 is a dedicated subwoofer with a radial cone optimised purely for low-frequency output, the B&C 15NBX100 is a broader-capability woofer that handles both bass and low-mid duties with lower distortion and more enclosure flexibility.

With 97 dB sensitivity, a Qts of 0.29, and a 35 Hz – 1500 Hz bandwidth, the B&C 15NBX100 works well in vented enclosures, performs in horn-loaded designs, and has enough Qts flexibility for builders to explore moderately sealed alignments. The demodulating ring is the headline feature that separates it from the NW100 — it keeps harmonic and intermodulation distortion measurably lower as power and excursion increase, which matters in systems where the 15-inch driver is operating up into the low-mid range rather than being filtered to sub-only duties.

B&C recommends a 114-litre vented enclosure tuned to 35 Hz — the deepest tuning recommendation of any neo 15-inch woofer in the range, confirming that despite its woofer classification, the B&C 15NBX100 reaches into genuine sub-bass territory. A 4 Ω variant is also available for single-driver applications.

Design and Construction of the B&C 15NBX100

The B&C 15NBX100 uses a 100 mm (4-inch) copper voice coil wound on a glass fibre former. The 25 mm winding depth operating in an 11 mm magnetic gap yields 10 mm of linear one-way excursion (Xmax) with an additional 10 mm of travel (Xvar) before mechanical limits. That 20 mm total one-way excursion before damage provides reliable headroom for transient peaks during sustained high-power use — and the 10 mm Xmax is 1 mm more than the NW100, giving the B&C 15NBX100 a slight edge on linear displacement capability.

The motor uses a neodymium inside-slug magnet in a T-pole configuration, producing 1.1 T of flux density and a force factor (Bl) of 25 Tm. An aluminium demodulating ring in the motor assembly is the key differentiator from the NW100 — it reduces flux modulation in the voice coil gap, directly lowering harmonic and intermodulation distortion as excursion and power increase. The NW100 doesn’t carry a demodulating ring, which is why the B&C 15NBX100 produces cleaner output under load despite the slightly lower flux density (1.1 T vs 1.2 T) and force factor (25 Tm vs 28 Tm).

A ventilated voice coil gap allows air circulation around the coil, reducing power compression during sustained high-power operation. Suspension is handled by a double silicone spider with optimised compliance and a triple-roll surround. The exponential cone profile supports pistonic behaviour into the upper frequencies better than the NW100’s radial cone, making the B&C 15NBX100 a stronger choice for applications where the woofer operates beyond pure sub-bass duties.

TWP waterproof treatment on both sides of the cone provides full weather resistance. At 9.55 kg and 179 mm deep, the B&C 15NBX100 is the heaviest neo 15-inch driver in B&C’s range — the demodulating ring and the additional motor steel it requires add mass compared to the NW100’s 8.65 kg. The 14 mm flange thickness is the thinnest of any 100 mm coil 15-inch driver in the neo range.

Performance and Applications for the B&C 15NBX100

The B&C 15NBX100 delivers 97 dB sensitivity and 2% reference efficiency across a 35 Hz – 1500 Hz bandwidth. The sensitivity matches the NW100 exactly, and the power handling is identical at 1000 W AES. What the B&C 15NBX100 brings to the table is cleaner output, more excursion, and more versatile enclosure behaviour — the spec sheet equivalent of the NW100 is there, but the measured distortion performance and alignment flexibility are where the NBX100 pulls ahead.

The Thiele–Small parameters show a more balanced alignment profile than the NW100. A Qts of 0.29 and an EBP of 116 Hz place the B&C 15NBX100 in vented territory with meaningful flexibility — builders can tune for punchy mid-bass output or lower for sub-bass extension depending on their application. B&C recommends a 114-litre (4 ft³) vented enclosure tuned to 35 Hz — a notably deep tuning that delivers extended low-frequency response from a 15-inch driver. The higher Qts compared to the NW100’s 0.22 means the B&C 15NBX100 also responds better to smaller vented alignments without the thin, over-damped character that very low Qts drivers can produce in undersized cabinets.

The choice between the B&C 15NBX100 and the NW100 comes down to priorities. If you need maximum motor authority and the lowest possible Qts for a tightly tuned vented or horn-loaded sub, the NW100’s 28 Tm Bl and 0.22 Qts are the right tool. If you need lower distortion, more excursion, more enclosure flexibility, and an exponential cone that behaves better in the upper bass and low-mid frequencies, the B&C 15NBX100 is the more refined choice.

Ideal applications for the B&C 15NBX100 include:

• High-power two-way and three-way systems where the 15-inch handles full bass duties
• Vented sub and bass cabinets tuned low for genuine sub-bass extension
• Touring speaker systems where sustained power handling and low distortion are priorities
• Dual-driver cabinets using 8 Ω parallel pairs for 4 Ω loading
• Applications where the demodulating ring’s distortion reduction justifies the weight premium over the NW100

Specifications – B&C 15NBX100

• Nominal Diameter: 380 mm (15 in)
• Nominal Impedance: 8 Ω
• Minimum Impedance: 6.4 Ω
• Nominal Power Handling: 1000 W
• Continuous Power Handling: 2000 W
• Sensitivity: 97 dB
• Frequency Range: 35 Hz – 1500 Hz
• Voice Coil Diameter: 100 mm (4 in)
• Winding Material: Copper
• Former Material: Glass Fibre
• Winding Depth: 25 mm (1 in)
• Magnetic Gap Depth: 11 mm (0.43 in)
• Flux Density: 1.1 T
• Magnet Material: Neodymium (inside slug)
• Cone Shape: Exponential
• Cone Treatment: TWP Waterproof (both sides)
• Surround Shape: Triple Roll
• Spider: Double Silicone
• Pole Design: T-Pole
• Net Weight: 9.55 kg (21.05 lb)

Thiele–Small Parameters – B&C 15NBX100

• Fs: 36 Hz
• Re: 5.1 Ω
• Qes: 0.31
• Qms: 4.2
• Qts: 0.29
• Vas: 125 dm³ (4.4 ft³)
• Sd: 855 cm² (132.5 in²)
• η0: 2%
• Xmax: 10 mm
• Xvar: 10 mm
• Mms: 151 g
• Bl: 25 Tm
• Le: 2 mH
• EBP: 116 Hz

Mounting Information – B&C 15NBX100

• Overall Diameter: 393 mm (15.5 in)
• Bolt Circle Diameter: 374 mm (16.7 in)
• Baffle Cutout Diameter: 353 mm (13.9 in)
• Depth: 179 mm (7.05 in)
• Flange and Gasket Thickness: 14 mm (0.55 in)
• Air Volume Occupied by Driver: 6 dm³ (0.21 ft³)
• Recommended Enclosure Volume: 114 dm³ (4 ft³)
• Recommended Tuning Frequency: 35 Hz

Conclusion – B&C 15NBX100 Woofer

The B&C 15NBX100 is the low-distortion alternative to the NW100 at the top of B&C’s neo 15-inch range. It matches the NW100’s 1000 W AES power handling and 97 dB sensitivity while adding the aluminium demodulating ring, exponential cone, more linear excursion, and a higher Qts that opens up enclosure options. The trade-off is 0.9 kg of additional weight and a slightly lower force factor — but for applications where output quality matters as much as output quantity, the B&C 15NBX100 is the more refined choice.

The 35 Hz recommended tuning is the deepest of any neo 15-inch woofer-class driver B&C makes, which means the B&C 15NBX100 reaches into sub-bass territory that most exponential-cone woofers can’t access. Combined with the 10 mm Xmax, you get a driver that genuinely bridges the gap between woofer and sub — handling full bass section duties in a two-way system while reaching deep enough to eliminate the need for a dedicated sub in many applications.

For high-power touring tops, premium two-way systems, and any build where the 15-inch driver needs to deliver 1000 W of clean, low-distortion bass from sub frequencies through the low-mids, the B&C 15NBX100 is the neodymium 15-inch that does it all — with the demodulating ring ensuring it does it cleanly.

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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.