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 largecontact 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
Mounting and Shipping Info
Nominal Diameter152 mm ( in)
Nominal Impedance16 Ω
Minimum Impedance11.5 Ω
Nominal Power Handling1200 W
Continuous Power Handling2260 W
Frequency Range200 - 6300 Hz
Voice Coil Diameter44 mm (1.73 in)
Surround ShapeTriple roll
Woofer Cone TreatmentWeather protected
Recommended Enclosure4.0 dm3 (0.14 ft3)
Recommended Tuning120 Hz
Resonance Frequency112 Hz
Vas5.9 dm3 (0.21 ft3)
Sd130.0 cm2 (20.15 in2)
Overall Diameter162 mm (6.38 in)
Bolt Circle Diameter170 mm (6.69 in)
Baffle Cutout Diameter148.0 mm (5.83 in)
Depth73 mm (2.87 in)
Flange and Gasket Thickness11 mm (0.43 in)
Net Weight1.25 kg (2.76 lb)
Shipping Weight1.45 kg (3.2 lb)
Shipping Box185x170x85 mm (7.28x6.69x3.35 in)
2 hours test made with continuous pink noise signal within the range Fs-10Fs. Power calculated on rated minimum impedance. Loudspeaker in free air.
Power on Continuous Program is defined as 3 dB greater than the Nominal rating.
Applied RMS Voltage is set to 2.83 V for 8 ohms Nominal Impedance.