SPEAKER 18SOUND 21" 21NLW9601-4ohms

The 21NLW9601 is a 21 inch neodymium high performance transducer. It is the evolution of the 21NLW9600 speaker. The transducer is suitable for high loading, ultra-low frequency horn loaded as well as bandpass subwoofer designs. For optimum results recommended amplifier should be able to deliver 3600 Watt program power without clipping. At the heart of the transducers stands the improved Triple Silicon Spider (TSS) lets the 21NLW9601 being able to control the moving mass with exceptional linearity, showing an exceptional stability of mechanical parameter values in the long term. The transducer design features include a high performance large displacement suspension system for improved cone control even at very high level of SPL matching. The state-of-the-art 5,3" diameter ISV copper voice coil shows a inside-outside split winding, four layers design, enabling the 21NLW9601 to handle up to 3600W program power. Bl force factor as well as all electro-dynamic parameters are linear within the working range. This, together with the high excursion behavior - 70 mm before damage, ±14 mm linear Xmax - makes the 21NLW9601 an extremely low distortion, highly dynamic transducer. The already low distortion and sound quality are further improved by an aluminum Single Demodulating Ring (SDR technology) that flatten impedance and phase with a constant power transfer. The 21NLW9601 has been developed after intense FEA and fluido-dynamics simulation and testing, focusing on dissipating the heat generated by the powerful 5.3" coil. Special attention was given to the optimization of air flow into the gap without introducing audible noise. A special low density material air diffractor placed into the backplate acts as a cooling system, increasing the power handling capability and lowering the power compression figure. Weight reduction was a key development aspect of the 21NLW9601, resulting in a net value of 14kg (30,9b). The carbon fiber reinforced, straight ribbed cone shows a proprietary resin treatment for extra pulp strength and water repellent properties. A special coating applied to both the top and back plates makes the transducer far more resistant to the corrosive effects of salts and oxidization.

• 98 dB SPL 1W / 1m average sensitivity
  135 mm (5.3 in) split winding four layers ISV copper coil
  3600 W program power handling
  Carbon fiber reinforced treated cellulose cone
  Triple Silicon Spider (TSS) improves excursion control and linearity even in extreme loading and SPL conditions
  Single Demodulating Ring (SDR) for lower distortion
  Low noise cooling design for very low power compression
  Suitable for bandpass and horn loaded subwoofer designs

General
Product type	Cone driver
Brand	Eighteen Sound
Manufacturer reference	21NLW9601
Product code	ALT219601WF08NA - 022218N010
Informations
Nominal impedance	8 ohm
Dimensional category	21 inch
Frequency coverage type	Sub, Low
Manufacturer sensitivity	96 dB
Calculated sensitivity	96.41 dB
Nominal power handling	1800 W
Max power handling	3600 W
Bandwidth	25÷2000 Hz
Fundamental parameters
Sd	1662 cm²
Mms	408 gr
Cms	46 µm/N
Le	3.1 mH
Re	5.9 ohm
BL	43 T.m
Small signal parameters
Fs	37 Hz
Qes	0.31
Qms	5.5
Qts	0.29
Vas	175 L
Datas
Xmax	±14 mm
EBP	119 Hz
Zmin	7.9 ohm
Fs / Qts	128 Hz
Vas * Qts²	14.72 L
Calculated efficiency	2.75 %
Weight	~14 kg
Demodulation ring	Yes
Dimensions
Voice coil diameter	5.3" inch
Outside diameter	545 mm
Baffle cutout diameter	492 mm
Depth	250 mm
Front thickness	18 mm
Depth after front	232 mm
Diamètre aimant (mm)	170 mm
Shape & Materials
Front chape	Cylindrical
Magnet type	Neodymium
Basket masterial	Aluminium
Cone material	Paper / Carbon fibers