18 Sound 6NMB420 speaker, 8 ohm, 6 inch

The 6NMB420 is a 44mm voice coil 6.5 inch neodymium midbass transducer designed for mid low frequency reproduction in system designs where high intelligibility is required.

When compared to our 6ND410 state-of-the-art midrange transducer, 6NMB420 offers a lower frequency resonance and a longer linear Xmax value. As a result the speaker shows an increased output around 250Hz, with a consequent slightly reduced output above 700Hz. It is suitable as mid-bass in line array systems or multiple way systems with high-pass crossover above 200 Hz and low-pass up to 3kHz; enclosure might be closed or vented with volume size starting from 2 lit.
The speaker offers a superb linearity: distortion values are furtherly minimized by new enhanced design criterias, developed by Eighteen Sound engineers, taking the 6NMB420 to very high level of performance.
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.
A consistent heat transfer is guaranteed by the encapsulation of the magnetic structure in the interior of the basket, offering a large contact space between the back plate and the dissipating structure.
Particular efforts were dedicated to the surround shape and material design in order to minimize the resonances on mid range frequencies. The triple roll design offers a consistent damping to typical bell modes. The 44 mm voice coil is made of light-weight aluminum wire and assures linearity and high power handling.
The ability to perform in humid environments is a key feature of the 6NMB420: this is achieved through a proprietary humidity repellent cone treatment.

100 dB SPL 1W / 1m average sensitivity
44 mm (1 3/4 in) voice coil
200 W AES power handling
External neodymium magnet assembly
Single Demodulating Ring (SDR) for lower distortion
Weather protected cone and plates for outdoor usage
Improved heat dissipation via Active Cooling System
Specially designed for line arrays and compact two way systems