This document provides specifications for the Scan-Speak Discovery series 18W/8434G00 midwoofer. It has a high output of 89dB, uses an aluminum ring magnet system, die-cast aluminum chassis, coated fiberglass cone, and rubber surround. Key parameters include a 50Hz resonance frequency, 8 ohm nominal impedance, 55W and 170W power handling, and 88.7dB sensitivity. The midwoofer has a 32mm voice coil and 13.4mm height, and provides a linear excursion of ±4.2mm and maximum excursion of ±8mm. Advanced parameters are also specified.

1. MIDWOOFER
18W/8434G00
The Discovery series offer traditional design, superior sound, a solid construction, and
a wide range of variants. Combining these elements - plus a wealth of technical
features and finesses - it gives our customers the possibility of acquiring a tailor-made
Scan-Speak solution with very good performance at a reasonable low price point!
KEY FEATURES:
— High Output 89dB @ 2,83V
— Magnet System w. Alu Ring
— Die cast Alu Chassis vented below spider
T-S Parameters
Resonance frequency [fs]
— Coated NRSC Fibre Glass Cone
— Low Damping SBR Rubber Surround
Electrical Data
50 Hz
Nominal impedance [Zn]
Mechanical Q factor [Qms]
7.58
Minimum impedance [Zmin]
Electrical Q factor [Qes]
0.46
Maximum impedance [Zo]
0.43
DC resistance [Re]
Total Q factor [Qts]
Force factor [Bl]
Mechanical resistance [Rms]
Moving mass [Mms]
Suspension compliance [Cms]
7.2 Tm
13.7 g
0.74 mm/N
132 mm
Effective piston area [Sd]
137 cm²
Sensitivity (2.83V/1m)
Ratio Bl/√Re
Ratio fs/Qts
97.9 Ω
5.6 Ω
0.55 mH
0.57 kg/s
Effective diaph. diameter [D]
Equivalent volume [Vas]
Voice coil inductance [Le]
8Ω
6.7 Ω
19.5 l
Power Handling
100h RMS noise test (IEC 17.1)
Long-term max power (IEC 17.3)
Voice coil diameter
Voice coil height
3.05 N/√W
Voice coil layers
Height of gap
Linear excursion
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.
170 W
Voice Coil and Magnet Data
88.7 dB
115 Hz
55 W
Max mech. excursion
Unit weight
N.C. Madsensvej 1 — 6920 Videbæk — Denmark — Phone: +45 6040 5200 — www.scan-speak.dk
32 mm
13.4 mm
2
5 mm
± 4.2 mm
± 8 mm
1.3 kg

2. MIDWOOFER
18W/8434G00
Advanced Parameters (Preliminary)
Electrical data:
Resistance [Re']
Free inductance [Leb]
Mechanical Data
5.83 Ω
0.0968 mH
Bound inductance [Le]
0.794 mH
Semi-inductance [Ke]
0.0669 SH
Shunt resistance [Rss]
2289 Ω
Force Factor [Bl]
Moving mass [Mms]
Compliance [Cms]
Mechanical resistance [Rms]
Admittance [Ams]
N.C. Madsensvej 1 — 6920 Videbæk — Denmark — Phone: +45 6040 5200 — www.scan-speak.dk
6.75 Tm
13.7 g
0.882 mm/N
0.180 kg/s
0.0920 mm/N