B&C 6NSM51 6.5″ Professional Midrange Driver
The B&C 6NSM51 is a professional 6.5-inch midrange LF driver engineered for applications requiring high output capability, lightweight construction, and controlled mid-frequency reproduction. Designed specifically as a dedicated midrange transducer, the B&C 6NSM51 combines a compact neodymium motor assembly with advanced cooling architecture and a lightweight moving system to deliver strong vocal clarity and transient accuracy across demanding professional applications.
Developed for compact line arrays, professional multi-way loudspeaker systems, stage monitors, and installed sound reinforcement applications, the B&C 6NSM51 has been optimized for efficient midrange performance where weight reduction and acoustic precision remain priorities. Its carefully engineered suspension system and motor topology allow the driver to maintain consistent output performance while preserving vocal intelligibility and articulation.
Key Features
- 250 W nominal power handling
- 500 W continuous program power capacity
- 51 mm (2 inch) aluminium voice coil
- 97 dB sensitivity
- 150 Hz – 6000 Hz frequency response
- Lightweight neodymium ring motor assembly
- Aluminium demodulation ring for reduced distortion
- Vented voice coil gap for improved thermal performance
- WP waterproof front cone treatment
- Dedicated professional midrange design
Lightweight Neodymium Motor Structure
The B&C 6NSM51 utilizes a neodymium ring magnet motor structure, allowing the driver to maintain strong magnetic performance while minimizing total system weight. This lightweight motor design makes the driver particularly suitable for portable sound systems and line array applications where reducing enclosure mass is important.
An integrated aluminium demodulation ring helps reduce inductance variation while improving upper-frequency performance and minimizing distortion. This contributes to improved vocal clarity and smoother response characteristics across the intended operating range.
With optimized magnetic performance and efficient motor geometry, the driver maintains strong cone control and predictable transient behavior while preserving the efficiency required for professional sound reinforcement applications.
Voice Coil Construction and Thermal Performance
At the center of the B&C 6NSM51 is a 51 mm aluminium voice coil wound on a glass fibre former. The larger voice coil diameter improves thermal handling capability while the aluminium winding material helps reduce moving mass for faster transient response.
The driver supports 250 W nominal power handling and 500 W continuous program power capacity, allowing reliable operation in demanding professional applications requiring sustained output capability.
A vented voice coil gap improves airflow around the motor assembly, helping reduce thermal buildup and minimizing power compression during extended high-level operation. This cooling architecture contributes to more stable long-term performance.
Cone Geometry and Suspension Design
The B&C 6NSM51 utilizes an exponential cone profile combined with a triple roll surround geometry, optimized specifically for dedicated midrange applications.
A single spider suspension system maintains mechanical stability while preserving the controlled movement characteristics necessary for accurate midrange reproduction. The suspension design has been optimized for lower excursion applications where articulation and transient response are priorities.
The cone assembly incorporates WP waterproof front-side treatment, improving resistance to humidity and environmental exposure in both portable and installed sound reinforcement applications.
Optimized for Professional Midrange Applications
The B&C 6NSM51 has been engineered specifically for applications where dedicated midrange reproduction is required.
Its combination of lightweight moving mass, high efficiency, and strong power handling capability makes it suitable for demanding sound reinforcement systems requiring clear vocal projection and accurate instrument reproduction.
Typical applications include:
- Professional multi-way loudspeaker systems
- Compact line arrays
- Stage monitoring systems
- Vocal reinforcement systems
- Midrange sections in PA systems
- Installed sound reinforcement systems
Technical Specifications
Nominal Diameter: 170 mm (6.5 in)
Nominal Impedance: 8 Ω
Minimum Impedance: 6.0 Ω
Nominal Power Handling: 250 W
Continuous Program Power: 500 W
Sensitivity: 97 dB
Frequency Range: 150 Hz – 6000 Hz
Voice Coil Diameter: 51 mm (2 in)
Winding Material: Aluminium
Former Material: Glass Fibre
Magnet Material: Neodymium Ring
Cone Shape: Exponential
Surround Shape: Triple Roll
Spider Design: Single
Pole Design: T-Pole
Cone Treatment: WP Waterproof Front Side
Thiele-Small Parameters
Fs: 145 Hz
Re: 5.1 Ω
Qes: 0.38
Qms: 3.2
Qts: 0.34
Vas: 2.5 dm³
Sd: 132 cm²
η₀: 2.0 %
Xmax: ±3 mm
Xvar: ±4 mm
Mms: 12 g
BL Factor: 12.5 Tm
Le: 0.32 mH
EBP: 382 Hz
Mounting Information
Overall Diameter: 187 mm
Bolt Circle Diameter: 172 mm
Baffle Cutout Diameter: 145 mm
Depth: 80 mm
Flange and Gasket Thickness: 11 mm
Air Volume Occupied by Driver: 0.7 dm³
Net Weight: 1.2 kg
Shipping Weight: 1.4 kg
Shipping Box: 210 × 210 × 125 mm
Recone Kit: RCK06NSM518
Applications
The B&C 6NSM51 is engineered for professional dedicated midrange applications where lightweight construction, high sensitivity, and strong vocal clarity are priorities. Its neodymium motor assembly, optimized cooling architecture, and dedicated midrange tuning make it particularly suitable for compact line arrays, stage monitors, multi-way loudspeaker systems, and professional sound reinforcement applications.
For system designers requiring a lightweight professional midrange transducer optimized for vocal articulation and high-output performance, the B&C 6NSM51 provides an effective combination of efficiency, low weight, and dependable professional operation.
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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.
