18 Sound 8NMB420 High Output MB Neodymium Driver 8ohm
95 dB SPL 1W / 1m average sensitivity
51mm (2 in) Interleaved Sandwich Voice coil (ISV)
280 W AES power handling
External neodymium magnet assembly
Single Demodulating Ring (SDR) for lower distortion
Weather protected cone and plates for outdoor usage
Suitable for line arrays and compact two way systems
Description
The 8NMB420 neodymium transducer has been developed in response to a specific market requirement for a 8" midbass driver that combines excellent linearity with good efficiency and high power handling capabilities. 8NMB420 is primarily intended for use as a midbass driver in compact 2-way or multiway reflex enclosures comprising line arrays. The parameters had been chosen to offer significant low frequency output in vented enclosure with size starting from 20 lit. with a tuning frequency around 60Hz. The low pass filter might be positioned as high as 2000-2500Hz. Multiple 8NMB420 units might be used: the compact size reflects in the capability to have precise attack time. This characteristic makes it the ideal choice for stage monitoring and bass guitar amplification. The extremely powerful external neodymium magnet assembly assures high flux concentration, low power compression and excellent heat exchange. The levels of force factor and power handling are, as a consequence, at the upper professional level with best power to weight ratio. The exclusive dedicated double roll surround design offers enhanced linear travel and control, in order to reproduce precisely low frequency. The curvilinear paper cone is formed using a unique wood pulp composition designed to achieve the best possible rigidity and stiffness. The 50mm inside outside aluminum voice coil employs Interleaved Sandwich Voice coil (ISV) technology. It is composed by a high strength fiberglass former used to carry windings on both the outer and inner surfaces to achieve a mass balanced coil. This results in an extremely linear motor assembly which, in conjunction with the highly advanced design of the magnetic structure, provides a high force factor or BL. The voice coil is cooled incorporating airways between the chassis back plate and the magnet faceplate so that heated air is channeled away from the voice coil and gap and dissipated by the chassis basket. Thanks to the increasing use during outdoor audio events, the ability to perform in humid environments is a key feature of the 8NMB420. This is achieved trough a proprietary humidity repellent cone treatment without a moving speaker mass increase.
General Specifications
Nominal Diameter 200mm (8 in)
Rated Impedance 8 Ohm
AES Power 280 W
Program Power 400 W
Peak Power 800 W
Sensitivity 95 dB
Frequency Range 60 - 5500 Hz
Power Compression @-10dB 0,8 dB Power Compression @-3dB 1,7 dB
Power Compression @Full Power 2,2 dB Max Recomm. Frequency 2500 Hz Recomm. Enclosure Volume 10 - 40 lt. (0,35 - 1,41 cuft)
Minimum Impedance 5,9 Ohm at 25°C Max Peak To Peak Excursion 19 mm (0,7 in)
Voice Coil Diameter 51 mm (2 in)
Voice Coil winding material aluminum Suspension M-roll, Polycotton
Cone Curvilinear, Treated paper
Thiele Small Parameters
Fs 61 Hz
Re 5 Ohm
Sd 0,022 sq.mt. (34,1 sq.in.)
Qms 4
Qes 0,31
Qts 0,28
Vas 33 lt. (1,2cuft)
Mms 14,9 gr. (0.033 lb)
BL 10 Tm
Linear Mathematical Xmax ± 5,75 mm (±0,23 in)
Le (1kHz) 0,35 mH
Ref. Efficiency 1W@1m (half space) 95,6dB
Mounting information
Overall diameter 210 mm (8,3 in)
N. of mounting holes and bolt 6
Mounting holes diameter 6 mm (0,23 in) Bolt circle diameter 195-198 mm (7,68-7,8 in)
Front mount baffle cutout ø 186 mm (7,3 in)
Rear mount baffle cutout ø 184 mm (7,2 in)
Total depth 99 mm (3.9 in)
Flange and gasket thickness 14,5 mm (0,6 in)
Net weight 1,7 kg (3,7 lb)
Shipping weight 2,0 kg (4,4 lb)
Packaging Dimensions 235 x 235 x 150 mm (9,25 x 9,25 x 5,91 in)
