
N.C. Madsensvej 1 · 6920 Videbæk · Denmark · Phone: +45 6040 5200 · www.scan-speak.dk
MIDWOOFER 18WU/4741T00
The Illuminator midranges and midwoofers are in every aspect unusual designs with
the open construction, the extremely long linear excursion and patented under-hung
SD-
3 (Symmetrical Drive) neodymium motor system, which due to copper caps and its
construction ensures very low distortion, adding the unique patented cones, low-loss
linear suspension the result is: “The Very Best Money Can Buy”!
KEY FEATURES:
· Under-Hung Neodymium Motor Design
· Patented Sandwich Paper Cone
· Low-Loss linear suspension
· Patented Symmetrical Drive (SD-3)
· Exceptionally Long Linear Excursion
· Patented Design
Notes:
IEC specs. refer to IEC 60268-5 third edition.
All Scan-Speak products are RoHS compliant.
Data are subject to change without notice.
Datasheet updated: February 22, 2011.
T-S Parameters
Resonance frequency [fs] 30 Hz
Mechanical Q factor [Qms] 3.56
Electrical Q factor [Qes] 0.32
Total Q factor [Qts] 0.29
Force factor [Bl] 6 Tm
Mechanical resistance [Rms] 1.00 kg/s
Moving mass [Mms] 18.9 g
Suspension compliance [Cms] 1.49 mm/N
Effective diaph. diameter [D] 140 mm
Effective piston area [Sd] 154 cm²
Equivalent volume [Vas] 49.4 l
Sensitivity (2.83V/1m) 87.2 dB
Ratio Bl/√Re 3.35 N/√W
Ratio fs/Qts 102 Hz
Electrical Data
Nominal impedance [Zn] 4 Ω
Minimum impedance [Zmin] 4.5 Ω
Maximum impedance [Zo] 38.8 Ω
DC resistance [Re] 3.2 Ω
Voice coil inductance [Le] 0.5 mH
Power Handling
100h RMS noise test (IEC 17.1) 80 W
Long-term max power (IEC 17.3) 150 W
Voice Coil and Magnet Data
Voice coil diameter 42 mm
Voice coil height 8 mm
Voice coil layers 4
Height of gap 20 mm
Linear excursion ± 9 mm
Max mech. excursion ± 16 mm
Unit weight 1.7 kg