PASpeaker-Base

18 Sound

18 Sound 18LW2400

18 Sound 18LW2400: 18″ subwoofer driver with ferrite motor, 4″ voice coil and Qts 0.31 – the manufacturer gives 220 L as the enclosure volume.

Current · Last checked: 2026-09-28

Share via …
Schematic cross-section: 18″ driver with ferrite motor Side section: on the left the motor with a large ferrite ring magnet, pole piece and top plate with the air gap. The voice coil sits in the gap on its former, held by the spider. To the right the cone opens out with its dust cap, with the surround at the edge of the basket. The drawing shows the construction, not the dimensions of a particular model.
Schematic cross-section of a driver with a ferrite motor. The drawing shows the construction, not the dimensions of this model; the manufacturer has a product photo.
Type
Subwoofer driver
Nominal size
18″
Nominal impedance
8 Ω Manufacturer
Minimum impedance
6.3 Ω Manufacturer
Sensitivity
98 dB 2.83 V / 1 m Manufacturer
Frequency range
31 Hz – 2,500 Hz Manufacturer
Voice coil Ø
100 mm Manufacturer
Winding height
not available
Gap depth
not available
Flux density
not available
Magnet
ferrite
Weight
12.8 kg Manufacturer
Baffle cut-out Ø
416 mm Manufacturer
Overall diameter
462 mm Manufacturer
Mounting depth
214 mm Manufacturer
Displacement
not available
Recommended enclosure volume
220 – 220 L Manufacturer

Sensitivity is referenced to 2.83 V at 1 m, i.e. to 1 W only at exactly 8 Ω. The manufacturer does not state Cms; the value is left empty here.

Simulation from the datasheet values above. The suggestions are calculated, not stated by the manufacturer.

Bass reflex Calculated

The EBP is above 100 – by the rule of thumb, this points to a vented enclosure (bass reflex). This is based on an EBP of 109.4.

Net volume
160 L
Tuning frequency
45 Hz
F3 (−3 dB)
42.7 Hz
F6 (−6 dB)
38.6 Hz
F10 (−10 dB)
34.2 Hz
Sensitivity (2.83 V / 1 m)
99 dB
Max. SPL at 42.7 Hz
126.9 dB
Max. SPL at 85.4 Hz
129.7 dB
Xmax limits below
81.7 Hz
Ports
1 × 315 mm
Port area for 17 m/s
784 cm²
Max. port velocity
17.1 m/s
Port length
48.8 cm
1020501002005001k8090100110120130140Frequency (Hz)Level (dB SPL)
  • at 1,200 W
  • Maximum SPL (limited by Xmax)
  • Power into 8 Ω (nominal impedance of the wiring).
  • Flattest alignment: lowest F3 without the response rising more than 0.25 dB above the passband level or dropping more than 0.5 dB at 2 × F3.
  • The 17 m/s limit (about 5 % of the speed of sound) is a common rule of thumb against port noise, not a standard. Rounded port ends allow higher values.
  • Lumped-element Thiele/Small model, Half space, 1 m, chamber losses QL 7, Le as a plain inductance, no room influence. At high levels (heating, non-linear Bl and Cms) real results are lower.

Open in the designer

Small-signal parameters as stated by the manufacturer. They change with temperature and level.

Fs
35 Hz
Re
5 Ω
Le
1.35 mH (at 1,000 Hz)
Qts
0.31
Qes
0.32
Qms
7.2
Vas
230 L
BL
25.6 T·m
Mms
192 g
Cms
not available
Sd
1,225 cm²
Xmax
9.5 mm
Xdamage
not available
Vd
not available
EBP
not available
Efficiency η₀
not available

We recalculate dependent values from the datasheet. We flag deviations above 3 %.

Recalculated parameters
CheckFormula DatasheetCalculatedResult
Qts from Qes and Qms Qts = Qes · Qms / (Qes + Qms) 0.31 0.306 consistent
  • Continuous power (standard not stated)1,200 W
  • Programme power2,400 W

18 Sound tests rated power handling for two hours with pink noise in the range Fs to 10 × Fs, free-air mounted, referenced to the minimum impedance. Programme power is defined as 3 dB above rated power handling – i.e. a calculated figure.

  1. Tier A · primary source

    18 Sound 18LW2400 (8 Ω) – Product page with Thiele-Small parameters

    Eighteen Sound S.r.l. · accessed on 28 September 2026

  2. Tier A · primary source

    Application Note – Horn Loaded 18'' Subwoofer (18H_v1.pdf)

    Eighteen Sound Srl · 11 July 2017 (Date from file metadata) · accessed on 13 September 2026