18SOUND 18NLS4000
18SOUND (Eighteen Sound) 18NLS4000 — 18" / 18 inch · Hi-Fi/Cinema Woofer · Subwoofer / Bass · Neodymium
4" voice coil · 4 Ω
Part no.: 42A-CHS-TT-18S-0044
Documents
18SOUND 18NLS4000 — 18" · Woofer
1200 W AES · 88 dB Sensitivity · Frequency range 28 Hz – 500 Hz
Technical data
- Diameter: 18 "
- Voice coil: 4 "
- Power handling: 1200 W AES
- Sensitivity: 88 dB
- Impedance: 4 Ω
- Magnet: Neo
- Weight: 12 kg
- Mounting depth: 250 mm
- Frequency range: 28 – 500 Hz
Datasheet (PDF) · Manufacturer page
Series: NLS · Part no.: 42A-CHS-TT-18S-0044
18Sound 18NLS4000: 18" long-throw subwoofer with 22.3 mm Xmax for cinema and home theatre
The 18Sound 18NLS4000 breaks the usual PA pattern: an 18" driver with a neodymium motor, 4" voice coil and 1,200 W AES whose stated range ends at 500 Hz and whose cone moves 22.3 mm linearly. 18Sound positions it as a hi-fi and cinema woofer, and that is exactly where it shines: Fs 27 Hz, Qts 0.35 and a moving mass of 433 g are the ingredients for a sub that prioritises extension and excursion over efficiency. Sensitivity is accordingly 88 dB, well below what light PA bass drivers achieve.
The motor applies 24.2 Tm to a 4 Ω coil with Re 2.9 Ω, and a Qms of 13.7 indicates a suspension with very low mechanical losses. Vas 168 l fits a driver that, despite its long throw, is not extremely compliant. In the database the Beyma 18PWB1000Fe/S with Fs 27 Hz and Qts 0.38 is the closest match; from the same manufacturer the 18NLW4100 (Qts 0.34) and the 18LW2420 (Qts 0.36) are the relatives for PA use with more efficiency but less excursion.
Use and enclosure
With an EBP of 75 the 18NLS4000 is one of the few 18" drivers where a sealed enclosure genuinely makes sense. The guideline is about 55 l with a system resonance of 55 Hz; combined with DSP equalisation and the 22.3 mm Xmax that turns into a compact home theatre sub with very clean transient behaviour. If you want deep output without equalisation, go vented: guideline around 124 l tuned to 29 Hz, with a lower cut-off f3 near 31 Hz. Both variants can be worked through with real dimensions in the enclosure calculator at 42.audio.
The crossover to the satellites in cinema and home theatre subs typically sits far below the 500 Hz ceiling; the inductance of 2.6 mH and the heavy cone argue against any midrange use anyway. You compensate for the low sensitivity with amplifier power: 1,200 W into 4 Ω is the continuous rating, and at 88 dB that figure is actually needed to reach reference levels in large rooms.
What to look out for
- 4 Ω nominal, Re 2.9 Ω: the amplifier must be stable into 4 Ω; design around 1,200 W AES.
- 88 dB sensitivity: deliberately low, excursion instead of efficiency. Budget power accordingly.
- Xmax 22.3 mm at Mms 433 g: long-throw concept, ideal for sealed boxes with DSP.
- Mounting depth 250 mm: the deepest driver in the 18" range, check cabinet depth.
- 12 kg despite neodymium: the heavy cone and long-throw suspension add up.
Frequently asked questions
Is the 18NLS4000 suitable for PA sound reinforcement?
Only with reservations. 88 dB sensitivity means a PA driver such as the 18NLW4100 is much louder at the same power. The 18NLS4000 is meant for cinema, home theatre and studio use, where extension, excursion and transient behaviour matter more than maximum level per watt.
Sealed or bass reflex?
Both work, the EBP of 75 leaves the choice open. Sealed around 55 l with DSP equalisation is compact and transient-accurate, and the 22.3 mm Xmax provides the necessary headroom. Vented around 124 l tuned to 29 Hz plays down to about 31 Hz without equalisation and needs less amplifier power.
Which amplifier fits?
A channel with around 1,200 W into 4 Ω, ideally with DSP for equalisation and high-pass. Because the driver only delivers 88 dB, the power is genuinely needed here rather than just headroom. Make sure a limiter restricts excursion below the tuning frequency.
18Sound 18NLS4000: manufacturer, spellings and classification
18Sound, 18 Sound and Eighteensound all refer to the same manufacturer: Eighteen Sound S.r.l. of Reggio Emilia, Italy. The 18NLS4000 is a 18-inch woofer with neodymium magnet from the NLS series, available from 42.audio, 18Sound dealer in Germany, with datasheet and full specifications in the driver database.
At 42.audio you get the 18SOUND 18NLS4000 with datasheet PDF, all key data in the driver database and the enclosure calculator. More drivers from this manufacturer: Atlas 18Sound.
Thiele-Small parameters
| Nominal impedance | 4 Ω |
|---|---|
| Resonance frequency fs | 27 Hz |
| Total Q Qts | 0.35 |
| Electrical Q Qes | 0.36 |
| Mechanical Q Qms | 13.7 |
| Equivalent volume Vas | 168.0 l |
| Moving mass Mms | 433.0 g |
| Cone area Sd | 1,225 cm² |
| Linear excursion Xmax | 22.3 mm |
| Force factor BL | 24.2 Tm |
| DC resistance Re | 2.9 Ω |
| Voice coil inductance Le | 2.6 mH |
Enclosure suggestion
The EBP of 75 is in the intermediate range — either works; sealed plays tighter, bass reflex deeper and louder. EBP = fs / Qes = 27 / 0.36
Sealed (Qtc 0.707)
- Enclosure volume Vb
- 54.5 l
- System resonance Fc
- 55 Hz
- Cut-off frequency F3
- 55 Hz
Bass reflex (QB3 after Small)
- Enclosure volume Vb
- 105.1 l
- Tuning frequency Fb
- 31 Hz
- Cut-off frequency F3
- 33 Hz
Vb is the required net internal volume, Fb the tuning frequency of the reflex port and F3 the frequency at which the level has dropped by 3 dB. Calculated approximation after Small. A starting point for simulation, not a finished build plan.
Comparable drivers
Same size, same type, Qts within ±30 %.
- FaitalPRO 18FH500fs 30 Hz · Qts 0.35 · Vas 417.9 l · in the database
- 18 Sound 18TLW3000fs 32 Hz · Qts 0.35 · Vas 185 l · in the database
- 18 Sound 18NLW4100fs 31 Hz · Qts 0.34 · Vas 180 l · in the shop
- FaitalPRO 18XL1600fs 32 Hz · Qts 0.36 · Vas 211.4 l · in the database
- Beyma 18PWB1000Fe/Sfs 27 Hz · Qts 0.38 · Vas 317 l · in the shop
- 18 Sound 18LW2420fs 34 Hz · Qts 0.36 · Vas 196 l · in the shop
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Low Frequency |
| Series | NLS |
| Magnet | Neo |
| Impedance (Ω) | 4 |
| Power handling (W) | 1200 |
| Sensitivity (dB) | 88 |
| Frequency from (Hz) | 28 |
| Frequency to (Hz) | 500 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 18 |
| Voice coil (inch) | 4 |
| Mounting depth (mm) | 250 |
| Weight (kg) | 12 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 2.9 |
| Le (mH) | 2.6 |
| Fs (Hz) | 27 |
| Qms | 13.7 |
| Qes | 0.36 |
| Qts | 0.35 |
| Vas (l) | 168 |
| Xmax (mm) | 22.3 |
| BL (Tm) | 24.2 |
| Mms (kg) | 0.433 |
| Sd (m²) | 0.1225 |