18 Sound 10NCX750 – Neodymium 10-Inch Coaxial with 75 mm ISV Voice Coil, SDR, and 15-Litre Minimum Enclosure
The 18 Sound 10NCX750 is 18 Sound’s neodymium 10-inch coaxial transducer — and it carries specifications that redefine what a 10-inch point source can deliver. With 97.5 dB LF sensitivity from a 75 mm ISV copper coil with SDR distortion reduction, a 20 Tm force factor producing a Qts of 0.25 and an EBP of 246 Hz — the most motor-dominant alignment of any coaxial in 18 Sound’s entire catalogue — a 64 mm EWAL titanium HF compression driver delivering 105 dB, 80° conical dispersion, and suitability for enclosures as compact as 15 litres, the 18 Sound 10NCX750 packs the motor authority and technology suite of 18 Sound’s 12 and 15-inch coaxials into the lightest neodymium coaxial the company makes.
The 4.25 kg weight is lighter than every other neodymium coaxial in the range — including the 12NCX750’s 4.5 kg. A 10-inch coaxial with a 75 mm ISV coil, SDR, and titanium HF compression driver weighing less than the lightest 12-inch coaxial. That weight makes the 18 Sound 10NCX750 viable for compact stage monitors, ultra-small PA tops, and portable systems where per-driver weight directly determines whether the system is practical to carry.
The 15-litre minimum enclosure is the smallest of any coaxial in 18 Sound’s entire range. Where the 12NCX910 — the previous smallest — needs 25 litres, the 18 Sound 10NCX750 operates in 15 litres. A complete two-way coaxial point source in a cabinet smaller than many guitar amplifier heads. The 0.25 Qts and 246 Hz EBP confirm the extreme motor dominance that makes this compact enclosure work — the powerful motor keeps the bass tight and controlled even in the smallest volumes.
The 20 Tm force factor and 0.54 mH inductance bring 18 Sound’s premium motor engineering to the 10-inch format. The 20 Tm Bl is higher than the 12NCX750’s 17.5 Tm from a driver that’s one format size smaller. The 0.54 mH Le is the lowest of any 18 Sound coaxial. Every motor specification confirms the 18 Sound 10NCX750 is engineered for maximum control and minimum compromise from the 10-inch frame.
Design and Construction of the 18 Sound 10NCX750
The 18 Sound 10NCX750 integrates a two-way coaxial transducer system into a single chassis powered by a single neodymium magnet motor. The neodymium motor is the fundamental difference from the ferrite-powered 10CX650 — it provides higher flux density at dramatically lower weight (4.25 vs 6.2 kg) and enables the ISV/SDR technology suite that the ferrite 10CX650 doesn’t carry.
The LF section uses a 75 mm (3-inch) copper ISV (Interleaved Sandwich Voice Coil) with a 15 mm winding depth operating in a 7.6 mm magnetic gap. The 75 mm coil is the same diameter used on the 12NCX750 and the 15NCX910 platforms — 18 Sound’s standard coil for premium coaxial LF sections. The ISV architecture places conductor on both surfaces of the former for mass-balanced, linear motor behaviour. The copper winding sustains the 350 W AES / 700 W program power rating.
An aluminium demodulating ring (SDR) in the LF magnetic circuit reduces flux modulation during excursion. The SDR flattens LF impedance and phase with constant power transfer — the same distortion reduction technology found on the 12 and 15-inch neodymium coaxials. The ferrite 10CX650 doesn’t carry an SDR — the 18 Sound 10NCX750 is the first 10-inch coaxial in the range with this feature.
The 20 Tm force factor is the highest Bl of any 18 Sound 10-inch coaxial and higher than the 12NCX750’s 17.5 Tm. Twenty Tesla-metres driving 46 g of moving mass produces a Bl/Mms ratio of 0.435 Tm/g — the highest acceleration factor of any 18 Sound coaxial. The motor has more electromagnetic authority over the cone per gram of moving mass than any other coaxial in the range.
The Qts of 0.25 and EBP of 246 Hz are the most extreme motor-dominant alignment of any 18 Sound coaxial. The 0.25 Qts is lower than the 12NCX750’s 0.29 and the 15NCX910’s 0.33. The 246 Hz EBP is the highest in the coaxial range by a wide margin — confirming the 18 Sound 10NCX750 is designed exclusively for vented and horn-loaded enclosures where the powerful motor produces the tightest, fastest, most controlled bass output.
The 0.54 mH Le is the lowest inductance of any 18 Sound coaxial — lower than the 12NCX750’s 0.62 mH and substantially lower than the 12NCX910’s 0.78 mH and the 15-inch coaxials’ 1.1+ mH. The low inductance produces the flattest impedance behaviour in the upper LF range, supporting the smoothest crossover transitions and the most predictable response at the top of the LF operating band.
The curvilinear LF cone uses 18 Sound’s high-damping pulp composition with water-repellent treatment and corrosion-resistant plate coatings. The 5.5 mm Xmax with 7 mm Xvar provides displacement capability appropriate for the 10-inch format.
The HF section uses a 64 mm (2.5-inch) EWAL (Edge-Wound CCAW) voice coil driving a 60 mm titanium diaphragm. The CCAW (copper-clad aluminium wire) combines copper’s surface conductivity with aluminium’s core weight savings. The titanium dome is joined to a high-strength, high-temperature treated Nomex former at its upper bend edge — the same bent edge joint construction used across 18 Sound’s coaxial range.
A copper sleeve on the HF pole piece reduces inductance above 10 kHz. The proprietary 3P hybrid radial tangerine phase plug produces smooth wavefronts with low distortion and high manufacturing consistency. The specific HF exit profile maximises coupling with the 10-inch LF cone, shaping the combined 80° conical dispersion.
At 4.25 kg, 260 mm overall diameter, 230 mm baffle cutout, and 148 mm depth, the 18 Sound 10NCX750 matches the 10CX650’s cutout diameter (230 mm) and is 7 mm shallower (148 vs 155 mm). The 14 mm flange thickness provides a more substantial mounting interface than the 10CX650’s 8 mm.
Performance and Applications for the 18 Sound 10NCX750
The 18 Sound 10NCX750 delivers 97.5 dB LF sensitivity from 60 Hz and 105 dB HF sensitivity from the 1.2 kHz crossover point upward. The 7.5 dB sensitivity difference between sections is managed through the crossover network.
The 97.5 dB LF sensitivity is 3.5 dB above the ferrite 10CX650’s 94 dB — the neodymium motor and 20 Tm force factor extract significantly more output per watt from the 10-inch cone. The 350 W AES LF power handling is 75% more than the 10CX650’s 200 W. Combined, the 18 Sound 10NCX750 produces approximately 5.5 dB more maximum sustained LF output than the 10CX650 — a dramatic advantage that puts the neodymium 10-inch coaxial in the performance class of many 12-inch drivers.
The 80° conical dispersion is narrower than the 10CX650’s 90° but matches the 12NCX750 and 15NCX910 platforms. The tighter coverage provides more SPL at distance — concentrating the acoustic energy into a smaller listening window. For compact PA tops where the speaker needs to project into the audience, 80° is the more effective coverage angle. For Atmos ceiling applications where maximum coverage angle matters, the 10CX650’s 90° is the better choice.
The 15-litre minimum enclosure is the specification that opens up the most compact cabinet designs in the coaxial range. A 15-litre vented cabinet with the 18 Sound 10NCX750 is a complete two-way coaxial point source in a package roughly the size of a small bookshelf speaker. The 0.25 Qts ensures the bass stays tight and controlled in this compact volume — the extreme motor dominance prevents the boomy, underdamped response that higher-Qts drivers can produce in small enclosures.
The 246 Hz EBP places the 18 Sound 10NCX750 firmly in vented and horn-loaded territory. A sealed 15-litre enclosure would produce thin, over-damped bass from the 0.25 Qts. A vented 15-litre enclosure with appropriate port tuning produces punchy, fast mid-bass from approximately 70 Hz upward — the tight, defined low end that compact PA tops and stage monitors need.
The comparison to the ferrite 10CX650 defines two completely different 10-inch coaxial philosophies. The 10CX650 delivers wider coverage (90° vs 80°), more enclosure flexibility (0.35 vs 0.25 Qts), PEN polymer HF smoothness, Atmos-ready design, and lower cost from the ferrite motor. The 18 Sound 10NCX750 delivers higher LF sensitivity (97.5 vs 94 dB), more LF power (350 vs 200 W AES), stronger motor (20 vs 14 Tm Bl), lower inductance (0.54 vs 0.9 mH), SDR distortion reduction, titanium HF projection, lighter weight (4.25 vs 6.2 kg), and a smaller minimum enclosure (15 vs 30 litres). The 10CX650 is the wide-coverage, installed-sound coaxial. The 18 Sound 10NCX750 is the high-output, compact-cabinet, professional-PA coaxial.
The 18 Sound 10NCX750 is the lightest neodymium coaxial 18 Sound makes. At 4.25 kg, it weighs 250 g less than the 12NCX750’s 4.5 kg — a 10-inch coaxial lighter than the lightest 12-inch. For ultra-portable systems, lightweight stage monitors, and applications where every gram matters, the 18 Sound 10NCX750 sets the weight floor for neodymium coaxial performance.
The 0.54 mH Le and 20 Tm Bl together produce a motor characterisation that DSP-based systems will exploit effectively. The low inductance means predictable impedance behaviour. The high Bl means predictable force behaviour. The low Qts means predictable transient behaviour. The 18 Sound 10NCX750 is a driver that responds precisely to the amplifier’s signal — the kind of transducer that makes DSP processing effective because the driver does what the signal tells it to do.
Conclusion – 18 Sound 10NCX750 Coaxial Driver
The 18 Sound 10NCX750 is the most motor-dominant, lightest, and most compact-enclosure coaxial in 18 Sound’s entire range. The 0.25 Qts and 246 Hz EBP are the most extreme motor-dominant alignment of any 18 Sound coaxial. The 15-litre minimum enclosure is the smallest. The 4.25 kg weight is the lightest of any neodymium coaxial — lighter than the 12NCX750 despite carrying the same 75 mm ISV coil and SDR technology.
The 20 Tm force factor, 0.54 mH inductance, and 97.5 dB sensitivity confirm a 10-inch motor that punches into 12-inch territory on output and control. The 64 mm EWAL titanium HF section with 3P tangerine phase plug delivers the professional HF quality that the ISV/SDR LF section demands.
For ultra-compact PA tops, lightweight stage monitors, portable speakers, and any application where a 10-inch coaxial needs to deliver 97.5 dB sensitivity with 350 W AES power handling from a 15-litre enclosure at 4.25 kg, the 18 Sound 10NCX750 is the neodymium 10-inch coaxial that carries 18 Sound’s full premium technology suite in the smallest, lightest, most motor-dominant package in the catalogue. ISV, SDR, EWAL, titanium, neodymium — the complete package at 4.25 kilograms.
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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.
