BMS BMS4507NDL 4507 NDL – 6.5″ Neodymium high-frequency Driver 150 W 8 Ohms

Features:

• Dual Diaphragm Coaxial Planar Wave Design (patent pending)
• Rectangular piston of 6.5" x 3/4" (162 x 19 mm)
• Neodymium Magnet Assembly
• Perfect acoustical coupling of individual units to create virtually continuous line source
• Extended Bandwith (400 - 22,000 Hz)
• With two Subsystems in one, each Driver covers a smaller Frequency Range for increased Power Handling, high Dynamic and extremely low Distortion
• Excellent Phase Coherence
• Perfect Time Alignment without Problems of Multi-Source Interference
• Ultra light Weight and small Size

The BMS 4507ND dual diaphragm coaxial planar wave driver radiates a coherent planar wave front form a rectangular piston without internal diffraction for superior dispersion control and high fidelity sound.

The driver is in fact a 2-way system employing two concentric annular ring diaphragms. Each driver covers a smaller frequency range for increased power handling, high dynamic and extremely low distortion.

This distinctive new transducer was engineered to work with 6.5-inch (162 mm x 19 mm) rectangular throat waveguides providing extremely high sensitivity.The patented design of the BMS 4507ND is a result of extensive dedicated research and development providing dramatic improvement in dynamic response, clarity and transparency. The larger annular midrange diaphragm covers the frequency range between 400 and 6,500 Hz with a smooth, linear response.

The high diaphragm excursion of max. + / - 0.8 mm results in high output and increased power handling up to 1,300 W peak.The ultra light annular diaphragm for the high range offers exceptional transient response with very high efficiency from 6 to 22 kHz.

The voice coils may be driven in conjunction with a passive crossover or driven individually from an active crossover.The unique voice coil technology employs a light weight Copper Clad Aluminum wire wound inside and outside of the Kapton™ former to improve the heat dissipation, dramatically increasing the acoustic output and reliability of the driver while minimizing the power compression. The use of high grade neodymium magnets provide improved performance while significantly reducing transducer weight.

The 4507ND is optimized for 0° to 15° vertical dispersion and allows a horizontal coverage up to 120° depending on the waveguide used.The unique design of the 4507ND dual diaphragm planar wave driver allows perfect acoustical coupling of individual units with excellent phase coherence and perfect time alignment to create virtually continuous line source.

Driver 140WRMS, 108dB, 500-18.000 Hz

2" high frequency compression driver. The particular mylar/titanium
diaphragm using a 3" edgewound flat aluminium wire voice coil and a
optimized high energy ceramic magnet assembly using a copper shorting
ring assembly produce smooth response and excellent sonic properties .

Specifications1
Throat Diameter 50 mm (2 in)
Nominal Impedance 8 Ω
Minimum Impedance 8 Ω
Power Handling
(1000 –20000 Hz)
Nominal2 80 W
Continuous Program3 160 W
Sensitivity (1W/1m)4 108 dB
Frequency Range 0.5 – 18 kHz
Recommended Crossover5 1000 Hz
Voice Coil Diameter 75 mm (3 in)
Winding Material Aluminium
Inductance 0.14 mH
Diaphragm Material Titanium
Flux Density 1.8 T
Also available in 16 Ω, data upon request

Mounting and Shipping Information
Four M6 holes 90° on 102 mm (4 in) diameter
Overall Diameter 170 mm (6.7 in)
Depth 67 mm (2.6 in)
Net Weight (1 unit) 4.5 kg (9.9 lb)
Shipping Weight (2 units) 9.6 kg (21.2 lb)
Shipping Box (2 units) 210x210x190 mm
(8.3x8.3x7.5 in)
1 Driver mounted on B&C ME 75 horn.
2 2 hours test made with continuous pink noise signal (6 dB crest factor) within
the specified range. Power calculated on rated minimum impedance.
3 Power on Continuous Program is defined as 3 dB greater than the Nominal rating.
4 Applied RMS Voltage is set to 2.83V for 8 ohms and 4V for 16 ohms Nominal
Impedance. Average SPL from 500 to 18000 Hz.
5 12 dB/oct. or higher slope high-pass filter.