18Sound 10NTLS2000 – Long-Throw 10-Inch Neodymium Subwoofer with Tetracoil Motor and Maximum Excursion

The 18Sound 10NTLS2000 is the long-throw subwoofer variant of 18Sound’s Tetracoil 51 mm voice coil platform — sharing the same motor architecture, the same 1.9 kg weight, and the same body dimensions as the 10NTLW2000 woofer, but with a fundamentally different voice coil configuration that produces 68% more linear excursion. Where the 10NTLW2000 optimises for mid-bass sensitivity at 98.5 dB with 4.4 mm Xmax, the 18Sound 10NTLS2000 optimises for bass displacement at 7.4 mm Xmax with 97 dB sensitivity.

The 7.4 mm Xmax is the specification that defines the 18Sound 10NTLS2000’s role. It places the driver in the same displacement class as the 10NW750 (7.5 mm) and close to the 10NTLW2500 (7.6 mm) — but from a 51 mm coil platform that weighs just 1.9 kg. The 10NW750 achieves similar excursion from a 75 mm coil at 3.8 kg. The 10NTLW2500 achieves it from a 64 mm coil at 3.1 kg. The 18Sound 10NTLS2000 achieves 7.4 mm from a 51 mm coil at 1.9 kg — the lightest driver in 18Sound’s 10-inch range by a significant margin to deliver this level of displacement.

The Tetracoil (TTC) dual-gap motor uses the same dual magnetic gap architecture as the 10NTLW2000. The difference is the coil itself: the 18Sound 10NTLS2000 uses a 19 mm winding depth versus the 10NTLW2000’s 13 mm. The deeper winding extends further above and below the 8.5 mm magnetic gap, which is the mechanism that produces more Xmax — more coil overhang means the coil stays partially inside the gap through a longer excursion stroke.

The trade-off is direct and transparent. The deeper winding adds moving mass (47 g vs 38 g), which reduces sensitivity (97 dB vs 98.5 dB) and narrows the upper bandwidth (3000 Hz vs 5000 Hz). Every specification that the 10NTLW2000 leads on — sensitivity, bandwidth, efficiency — the 18Sound 10NTLS2000 trades for the displacement and bass extension that subwoofer applications demand.

At 1.9 kg, 260 mm overall diameter, and 141 mm depth — physically identical to the 10NTLW2000 — the 18Sound 10NTLS2000 drops into the same cabinet as its woofer sibling. Available in 8 Ω.

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Design and Construction of the 18Sound 10NTLS2000

The 18Sound 10NTLS2000 uses a 51 mm (2-inch) aluminium dual voice coil operating in a Tetracoil (TTC) neodymium dual-gap motor assembly. The motor is shared with the 10NTLW2000 — same magnet assembly, same dual gap structure, same fundamental architecture. The voice coil winding is where the two drivers diverge.

The 19 mm winding depth is the engineering change that creates the 18Sound 10NTLS2000’s displacement advantage. In the same 8.5 mm dual magnetic gap, a 19 mm winding has 10.5 mm of overhang (5.25 mm on each side) versus the 10NTLW2000’s 13 mm winding with 4.5 mm of overhang (2.25 mm on each side). The additional 6 mm of total winding depth translates to 3 mm of additional linear excursion — 7.4 mm versus 4.4 mm.

The deeper winding adds conductor mass to the moving assembly. The 18Sound 10NTLS2000’s 47 g moving mass is 24% heavier than the 10NTLW2000’s 38 g — the additional 6 mm of aluminium wire wound on the former accounts for the increase. Heavier moving mass means slower acceleration per unit of force, which reduces sensitivity. The 97 dB sensitivity is 1.5 dB below the 10NTLW2000’s 98.5 dB — the mathematical consequence of more coil mass.

The 16.7 Tm force factor is slightly lower than the 10NTLW2000’s 17.9 Tm. The same motor producing marginally less Bl with a deeper coil is expected — the coil sections furthest from the gap centre experience slightly weaker flux, averaging the total force factor slightly downward. The 16.7 Tm driving 47 g still provides strong motor authority — the Qts of 0.26 confirms the motor has firm control over the heavier moving mass.

The Tetracoil dual-gap architecture provides the same thermal and Bl symmetry advantages as the 10NTLW2000. The doubled coil surface in the magnetic field dissipates heat twice as efficiently as a single-gap design, sustaining the 350 W AES / 700 W program power rating reliably. The symmetrical Bl shape maintains consistent force output across the 7.4 mm excursion range, keeping intermodulation distortion low even at high displacement levels.

The aluminium winding is a different material from the 10NTLW2000’s CCAW (copper-clad aluminium wire). Pure aluminium is lighter per unit of length than CCAW but has higher resistance per metre. For the deeper 19 mm winding where minimising coil mass is less critical than maximising conductor length in the gap, pure aluminium is the appropriate choice.

The 0.74 mH inductance is higher than the 10NTLW2000’s 0.63 mH — the deeper winding places more conductor in the gap, which increases the coil’s electromagnetic coupling and inductance. For the 3000 Hz upper bandwidth, the inductance behaviour is well-managed by the Tetracoil motor’s inductance linearisation.

The M-roll surround and curvilinear cone match the 10NTLW2000’s mechanical construction. The weather-protected cone treatment provides outdoor durability. At 1.9 kg, 260 mm overall diameter, 141 mm depth, 233 mm baffle cutout, and 10 mm flange — every physical dimension matches the 10NTLW2000 exactly. The two drivers are completely interchangeable in the same cabinet.

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Performance and Applications for the 18Sound 10NTLS2000

The 18Sound 10NTLS2000 delivers 97 dB sensitivity across a 50 Hz – 3000 Hz bandwidth. The 50 Hz lower frequency limit is 10 Hz deeper than the 10NTLW2000’s 60 Hz — the heavier moving mass and deeper winding push the resonance frequency down to 50 Hz, extending the driver’s useful bass range. The 50 Hz Fs confirms the 18Sound 10NTLS2000 reaches genuine sub-bass territory from a 10-inch frame.

The 3000 Hz upper bandwidth is significantly narrower than the 10NTLW2000’s 5000 Hz — the heavier 47 g moving mass reduces high-frequency extension. For subwoofer and bass applications, the 3000 Hz limit is more than adequate — the driver operates well below the crossover point to a compression driver or tweeter, typically in the 200–1500 Hz range.

The 7.4 mm Xmax combined with 346 cm² of radiating area produces substantial bass displacement from the 10-inch format. The volume displacement (Xmax × Sd) is approximately 256 cm³ — roughly 68% more than the 10NTLW2000’s displacement and comparable to the 10NW750’s figure. For compact subwoofer cabinets and bass sections in portable PA systems, this displacement capability means the 18Sound 10NTLS2000 moves enough air to produce genuine low-frequency output that the sensitivity-optimised 10NTLW2000 cannot.

The Thiele–Small parameters define a motor-dominant driver suited for vented enclosures. The Qts of 0.26 and 50 Hz Fs indicate the 18Sound 10NTLS2000 produces tight, well-controlled bass in tuned cabinets. The 38 dm³ Vas suggests optimal enclosure volumes in the 15–25 litre range depending on target tuning and response shape — compact enough for portable sub cabinets and bass sections in two-way systems.

The 350 W AES / 700 W continuous program power handling matches the 10NTLW2000. The Tetracoil motor’s doubled thermal dissipation sustains this rating through extended high-power operation, and the symmetrical Bl curve keeps the output clean at the high displacement levels the 7.4 mm Xmax enables.

The comparison to the 10NW750 is instructive. Both drivers produce similar Xmax (7.4 vs 7.5 mm). Both handle similar power levels (350 W AES vs 450 W). But the 18Sound 10NTLS2000 weighs half as much (1.9 vs 3.8 kg). The 10NW750 counters with dual distortion reduction (SDR + copper ring), wider bandwidth (5000 vs 3000 Hz), higher power handling, and 16 Ω availability. For sub-only applications where the driver operates below 1000 Hz, the 18Sound 10NTLS2000’s weight advantage is compelling.

The physical interchangeability with the 10NTLW2000 is the most practical advantage for system designers. One cabinet design can accept either driver — the 10NTLW2000 for mid-bass sensitivity or the 18Sound 10NTLS2000 for bass displacement. A product manufacturer can offer a two-way top with the 10NTLW2000 and a compact sub with the 18Sound 10NTLS2000, using the same cabinet platform for both.

Ideal applications for the 18Sound 10NTLS2000 include:

• Compact subwoofer cabinets where 10-inch format is required
• Bass sections in portable two-way systems needing maximum low-frequency displacement
• Line array bass elements where 1.9 kg per driver minimises total array weight
• Under-seat and distributed bass systems where compact subs are mandatory
• Systems pairing with the 10NTLW2000 using the same cabinet platform for bass and mid-bass
• Vented sub designs exploiting the 50 Hz Fs and 0.26 Qts for tight, controlled bass
• Applications where 7.4 mm Xmax from a 1.9 kg driver is the defining requirement
• Touring rigs where per-driver weight directly affects truck loading and rigging calculations

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Specifications – 18Sound 10NTLS2000

• Nominal Diameter: 260 mm (10 in)
• Nominal Impedance: 8 Ω
• Minimum Impedance: 5.7 Ω
• Nominal Power Handling: 350 W
• Continuous Power Handling: 700 W
• Sensitivity: 97 dB
• Frequency Range: 50 Hz – 3000 Hz
• Voice Coil Diameter: 51 mm (2 in)
• Winding Material: Aluminium
• Winding Depth: 19 mm
• Magnetic Gap Depth: 8.5 mm (dual gap)
• Motor Technology: TTC (Tetracoil Dual Voice Coil)
• Magnet Material: Neodymium
• Cone Treatment: Weather protected
• Surround Shape: M-Roll
• Net Weight: 1.9 kg (4.19 lb)

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Thiele–Small Parameters – 18Sound 10NTLS2000

• Fs: 50 Hz
• Re: 5.2 Ω
• Qes: 0.27
• Qms: 4.9
• Qts: 0.26
• Vas: 38 dm³ (1.34 ft³)
• Sd: 346 cm² (53.63 in²)
• Xmax: 7.4 mm
• Mms: 47 g
• Bl: 16.7 Tm
• Le: 0.74 mH

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Mounting Information – 18Sound 10NTLS2000

• Overall Diameter: 260 mm (10.24 in)
• Bolt Circle Diameter: 245 mm (9.65 in)
• Baffle Cutout Diameter: 233 mm (9.17 in)
• Depth: 141 mm (5.55 in)
• Flange and Gasket Thickness: 10 mm (0.39 in)
• Net Weight: 1.9 kg (4.19 lb)

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Conclusion – 18Sound 10NTLS2000 Subwoofer Driver

The 18Sound 10NTLS2000 is the displacement variant of 18Sound’s Tetracoil 51 mm platform — the same motor, the same body, the same 1.9 kg weight as the 10NTLW2000 woofer, but with a 19 mm winding depth that produces 7.4 mm of linear excursion versus the woofer’s 4.4 mm. The engineering trade-off is clean and deliberate: 68% more displacement in exchange for 1.5 dB less sensitivity and 2000 Hz less upper bandwidth.

The 1.9 kg weight is the 18Sound 10NTLS2000’s most compelling specification for subwoofer use. No other 10-inch driver in 18Sound’s range delivers 7.4 mm Xmax at this weight. The 10NW750 achieves similar displacement at double the mass (3.8 kg). The Tetracoil motor’s dual-gap architecture makes the extreme power-to-weight ratio possible, and the physical interchangeability with the 10NTLW2000 gives system designers a matched pair of drivers for bass and mid-bass from the same cabinet platform.

For compact subs, distributed bass systems, line array bass elements, and any application where a 10-inch driver needs to deliver maximum bass displacement from 1.9 kg of transducer, the 18Sound 10NTLS2000 is the driver that trades the 10NTLW2000’s mid-bass efficiency for the low-frequency displacement that bass reproduction demands. Same Tetracoil motor, same body, same weight — different coil, different mission, different output. The sub half of the lightest 10-inch platform in professional audio.