The BMS 4508ND 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 8-inch  (215.6 mm x 19 mm) rectangular throat waveguides providing extremely high  sensitivity.
The patented design of the BMS 4508 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 300 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 1300 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 minimises the power compression. The use  of high grade neodymium magnets provide improved performance while  significantly reducing transducer weight.
The 4508ND 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 4508ND  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.