18 Sound 15ND940 – Updated Flagship 15-Inch Neodymium Woofer Replacing the 15ND930
The 18 Sound 15ND940 is a high power, high output, extended low frequency neodymium transducer which meets the most stringent requirements in high-quality professional transducers and represents the updated version of the 18 Sound flagship 15ND930, to which it is a direct replacement with improved construction — the same generational succession pattern documented on the 12ND940/12ND930 pairing earlier in this session, here at 15 inches.
The high level of performance and sound quality have been achieved by exploiting the most advanced technologies available today. Thanks to its versatility, the 18 Sound 15ND940 can be used in two-way compact reflex enclosures, in multiway systems, and in high-loading subwoofers as small as 70 litres — spanning compact reflex, bandpass, and horn-loaded configurations, and specifically recommended for multiway systems and studio monitoring applications.
The neodymium magnet assembly assures high flux concentration, low power compression, and excellent heat exchange. This results in high levels of force factor and power handling with an optimum power-to-weight ratio. The 21.9 Tm force factor driving 108 g of moving mass produces 99 dB sensitivity and 3.2% reference efficiency — genuinely strong figures for a driver also carrying 9.5 mm of Xmax.
Available in 4, 8, and 16 Ω — the widest impedance range of any 15-inch driver documented in this session — the 18 Sound 15ND940 gives system designers maximum flexibility for single-driver and multi-driver line array configurations at this premium performance tier. 18 Sound now lists the 15ND930 as the alternative/current model.
Design and Construction of the 18 Sound 15ND940
The 75 mm (3-inch) copper voice coil assembly, with a 23.5 mm winding depth operating in a 9.0 mm magnetic gap, is wound on a strong fibreglass former to improve force transmission and power handling. The already low distortion and sound quality are further improved by the Demodulating Ring (SDR) that flattens impedance and phase with a constant power transfer, producing the driver’s well-controlled 0.7 mH inductance.
The deep-profile curvilinear cone, created from a special high-strength wood pulp, has been designed to achieve the best possible linearity within its frequency range. The cone surround is highly resistant to ageing and fatigue. The in-house developed cone treatment is a humidity repellent and significantly dampens bell-mode resonances — the same dual-function cone treatment philosophy documented across 18 Sound’s premium driver range throughout this session.
The 21.9 Tm force factor driving 108 g of moving mass produces 99 dB sensitivity and the 0.28 Qts / 131 Hz EBP alignment — solidly motor-dominant, consistent with a driver built for high-output professional applications spanning two-way, multiway, and subwoofer duty.
At 4.7 kg, 392 mm overall diameter, 354 mm baffle cutout, 184 mm depth, and 13 mm flange, the 18 Sound 15ND940 carries a lighter, more efficiently constructed chassis than several of the extreme subwoofer specialists documented earlier in this session (the 15NLW4500 at 11.4 kg, the 15NLW9401 at 7.5 kg), reflecting its positioning as a versatile, do-everything flagship woofer rather than a single-application extreme specialist.
Performance and Applications for the 18 Sound 15ND940
The 18 Sound 15ND940 delivers 99 dB sensitivity across a 38 Hz – 3500 Hz bandwidth. 18 Sound recommends a 70-litre (2.47 ft³) vented enclosure tuned to 45 Hz — a genuinely compact cabinet volume for a driver handling 1200 W continuous program, reflecting the extreme motor control the 0.28 Qts and 131 Hz EBP provide.
The driver’s stated versatility spans two-way compact reflex enclosures, multiway systems, and high-loading compact subwoofers as small as 70 litres across compact reflex, bandpass, and horn-loaded configurations — the same comprehensive application breadth documented on the 12ND940’s own feature summary, here delivered at 15 inches with correspondingly higher power handling (600 vs the 12-inch’s various figures) and displacement.
The 600 W AES / 1200 W continuous program power handling, combined with the 9.5 mm Xmax and 881 cm² radiating area, produces substantial sustained output and volume displacement appropriate for the studio monitoring and multiway system applications 18 Sound specifically recommends.
As the direct replacement for the 15ND930 with improved construction, the 18 Sound 15ND940 represents 18 Sound’s current thinking on what a flagship 15-inch neodymium woofer should deliver — extreme motor control, high power handling, exceptional sensitivity, application versatility, and now the widest impedance availability (4/8/16 Ω) of any 15-inch driver documented across this entire session.
Conclusion – 18 Sound 15ND940 Woofer
The 18 Sound 15ND940 is 18 Sound’s current flagship 15-inch neodymium woofer — the updated, improved-construction replacement for the 15ND930, mirroring the exact succession pattern documented on the 12-inch ND940/ND930 pairing earlier in this session. The 75 mm copper coil with SDR, 99 dB sensitivity, 600 W AES / 1200 W continuous program power handling, and the widest 15-inch impedance range (4/8/16 Ω) documented in this session combine to meet the most stringent requirements in high-quality professional transducers.
For builders seeking 18 Sound’s current best 15-inch neodymium woofer, spanning two-way, multiway, and subwoofer applications with exceptional sensitivity, power handling, motor control, and impedance flexibility, the 18 Sound 15ND940 is the driver 18 Sound built to meet the most stringent professional requirements at this diameter.
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About 18 Sound
18 Sound products are proudly made in Reggio Emilia, Italy, combining advanced technology with Italian craftsmanship. Known for their high-performance professional audio components, 18 Sound is a trusted name in the global audio industry. Their state-of-the-art manufacturing and strict quality control ensure exceptional reliability and sound clarity. 18 Sound products are designed to meet the demands of speaker builders and audio professionals, 18 Sound offers premium products with outstanding value and performance worldwide.
