15NMB420

High Output Midbass Neo Transducer

KeyFeatures

99 dB SPL 1W / 1m average sensitivity
75 mm (3 in) Interleaved Sandwich Voice coil (ISV)
450 W AES power handling
External neodymium magnet assembly
Single Demodulating Rings (SDR) for lower distortion
Weather protected cone and plates for outdoor usage
Specially designed for compact two way systems

Description

The 15NMB420 is a 380 mm (15 in) neodymium mid-bass transducer designed for professional monitoring and sound reinforcement.
The most extended bass, lowest distortion and best control is usually realized in properly designed vented enclosures. Typical enclosure sizes range from 80lit. up with tunings from 40 to 50Hz.
Low-frequency equalization is suggested in order to improve the bass output. A conservative idea of amplifier size ranges from 400-800W, allowing maximum output with no risk of speaker damage when properly used.
The neodymium magnet assembly assures high flux concentration, low power compression and excellent heat exchange, since the external magnet configuration is considerably more efficient than the traditional under-pole magnet topology. This allows to obtain high levels of force factor and power handling with a power to
weight ratio at the upper level of the category.
SDR (Single Demodulating Ring) technology has been used to reproduce instantaneous peaks on mid frequencies, reducing intermodulation distortion.
The high quality paper cone has a smooth, curvilinear profile design that eliminates bell-mode resonances within the intended frequency range. This is carried by a specially treated and damped multiple roll linen suspension designed to control excursion maintaining the piston action linearity.
The 15NMB420 employs a 75mm aluminum Interleaved Sandwich Voice coil (ISV), in which a high strength fiberglass former carries windings on both the outer and inner surfaces to achieve a mass balanced coil, resulting in an extremely linear motor assembly.
A proprietary humidity-block cone treatment has been implemented in order to perform in outdoor environments under adverse weather conditions. In addition, special treatment of both the face and back plates results in a product which is far more resistant to the corrosive effects of salts and oxidization than any other treatment in use.

Models

Model Code Information
022158N240 022158N240 8 Ohm
022154N250 022154N250 4 Ohm
027158N240 027158N240 8 Ohm
027154N250 027154N250 4 Ohm




15NMB420

High Output Midbass Neo Transducer

General Specifications

Nominal Diameter 380mm (15 in)
Rated Impedance 8 Ohm
AES Power 450W
Program Power 700W
Peak Power 1400W
Sensitivity 99dB
Frequency Range 40 - 5000 Hz
Power Compression @-10dB 0,7 dB
Power Compression @-3dB 2,1 dB
Power Compression @Full Power 3,4 dB
Max Recomm. Frequency 1700Hz
Recomm. Enclosure Volume 60 ÷ 140 lt. (2,1 ÷ 4,9 cuft)
Max Peak To Peak Excursion 36 mm (1,4 in)
Voice Coil Diameter 75 mm (3 in)
Voice Coil Winding Material aluminum
Suspension M-roll, Polycotton
Cone Curvilinear, Treated paper

Thiele Small Parameters

Fs 42 Hz
Re 5,6 Ohm
Sd 0,09 sq.mt. (139,5 sq.in.)
Qms 6
Qes 0,3
Qts 0,29
Vas 225 lt. (7,9 cuft)
Mms 73gr. (161,1 lb)
BL 19 Tm
Linear Mathematical Xmax ± 6,5 mm (±0,26 in)
Le (1kHz) 0,8 mH
Ref. Efficiency 1W@1m (half space) 99,3 dB

Mounting information

Overall diameter 387 mm (15,2 in)
N. of mounting holes and bolt 8
Mounting holes diameter 7,15 mm (0,3in)
Bolt circle diameter 370-371 mm (14,57-14,61 in)
Front mount baffle cutout ø 353mm (13,9 in)
Rear mount baffle cutout ø 357 mm (14,1 in)
Total depth 169,5 mm (6,7 in)
Flange and gasket thickness 11,5 mm (0,5 in)
Flange and gasket thickness 11,5 mm (0,5 in)
Net weight 3,9 kg (8,6 lb)
Shipping weight 4,8 kg (10,6 lb)
CardBoard Packaging dimensions 405 x 405 x 214 mm(15,94 x 15,94 x 8,43 in)
FREQUENCY RESPONSE CURVE OF 15NMB420 MADE ON 125 LIT. ENCLOSURE TUNED 50HZ IN FREE FIELD (4PI) ENVIRONMENT. ENCLOSURE CLOSES THE REAR OF THE DRIVER. THE THIN LINE REPRESENTS 45 DEG. OFF AXIS FREQUENCY RESPONSE
FREE AIR IMPEDANCE MAGNITUDE CURVE

Notes

(1) AES power is determined according to AES2-1984 (r2003) standard
(2) Program power rating is measured in 50 lit enclosure tuned 60Hz using a 40 - 400Hz band
(3) The peak power rating represents the maximum permitted instantaneous peak power level over a maximum period of 10ms which will be withstood by the loudspeaker without damage.
(4) Sensitivity represents the averaged value of acoustic output as measured on the forward central axis of cone, at distance 1m from the baffle panel, when connected to 2,83V sine wave test signal swept between 100Hz and 500Hz with the test specimen mounted in the same enclosure as given for (1) above.
(5) Frequency range is given as the band of frequencies delineated by the lower and upper limits where the output level drops by 10 dB below the rated sensitivity in half space environment.
(6) Power compression represents the loss of sensitivity for the specified power, measured from 50-500 Hz, after a 5 min pink noise preconditioning test at the specified power.
(7) Thiele - Small parameters are measured after the test specimen has been conditioned by 450 W AES power and represent the expected long term parameters after a short period of use.
(8) Linear Math. Xmax is calculated as (Hvc-Hg)/2 + Hg/4 where Hvc is the coil depth and Hg is the gap depth.