Data Sheet

FREQUENCY RESPONSE DATA*
IMPEDANCE
PREDICTED BASS RESPONSE
* Half space response measured in a 975 litre sealed box
18.0''
457 mm
19.1”
485 mm
7.75”
201 mm
8.66”
220 mm
• Please enquire about alternative impedances.
• A.E.S. power handling test. Pink noise bandpass filtered at 12 dB per octave with cutoff frequencies of 30 Hz and 300 Hz. Driver mounted in
free air, test signal applied at rated power for two hours.
• Please note that the frequency response measurements are supplied for comparison only and are not a measure of the low frequency
performance which may be achieved in a fully optimised system.
** Normalized bass response in 175 litre tuned to 35Hz
MOUNTING / SHIPPING INFORMATION
Overall Diameter
19.1” / 485 mm
Width Across Flats
18” / 457 mm
Flange Height
0.465” / 11.8 mm
Bafe Hole Diameter F/M
16.53” / 420 mm
Bafe Hole Diameter R/M
16.33” / 414 mm
Gasket Supplied
Front & Rear
Fixing Holes
8x 0.275” diam on 18.425
PCD / 8x 0.275 diam on
17.25 PCD 8x 7 mm diam
on 468 PCD / 8x 7 diam on
438.15 PCD
Depth
7.81” / 201 mm
Weight
27.6 lb / 12.5 kg
Recommended Enclosure Volume
4.41 - 14.12 cu ft /
125 - 400 litres
Shipping Weight
28.9 lb / 13.1 kg
Packing Carton Dimensions
250 x 520 x 520 mm
MATERIALS OF CONSTRUCTION
Former Material
Glass Fibre
Voice Coil
Copper ‘sandwich’ inside
and outside windings
Magnet Material
Ferrite
Chassis
Die-cast Aluminium
Cone
Curvilinear polycellulose
Surround / Edge Termination
Polyvinyl Damped Dbl. Half
Roll Linen
Dust Dome
Solid Paper
Connectors
Push-button Spring
Terminals
Polarity
Positive Voltage at Red
Terminal Causes Forward
Motion of Cone
THIELE SMALL PARAMETERS
FS Hz
36 Hz
RE Ohms
5.2 Ω
Qms
6.583
Qes
0.366
Qts
0.346
Vas Ltr
199
Vd litres
0.893
CMS (mm/N)
0.109
BL T/m
24
Mms (grms)
177.2
Xmax (mm)
8.25
Sd (cm
2
)
1134
Efciency %
2.488
Le (1k Hz)
2.23 mH
ELECTRO ACOUSTIC SPECIFICATIONS
Nominal Chassis Diameter
18”
Impedance
8 Ω
Power Handling
1000 w (A.E.S.)
Peak Power (6dB Crest Factor)
4000 w (A.E.S.)
Usable Frequency Range -6dB
35 Hz - 2.5 kHz
Sensitivity (1 w - 1 m)
100 dB
Moving Mass inc. Air Load
177 grams
Minimum Impedance Zmin
6.5 Ω
Effective Piston Diameter
14.84” / 377 mm
Peak Displacement Volume of
Cone Vd
0.893 litres
Magnet Weight
120 oz
Magnetic Gap Depth
0.43” / 11 mm
Flux Density
1.1 Tesla
Coil Winding Height
0.87” / 22 mm
Voice Coil Diameter
4.0” / 101.6 mm
The Colossus 18SB is intended for use as a high-output bass driver in multi way systems. It features a 4 inch
‘sandwich’ inside and outside windings voice coil, immersed in a symmetric magnetic eld yielding increased
linearity and lower distortion. This, coupled with a large Xmax of 8.25 mm and laminated silicone suspension,
ensures tight, punchy bass at high levels of excursion. The cone membrane, manufactured from polycellulose,
is much stronger and more durable than conventional paper pulp alternatives. This allows the driver to combine
high-sensitivity with the structural integrity required to produce undistorted low frequencies at extreme sound
pressure levels. The driver handles 1000 Watts (A.E.S.) continuous and can cope with peaks in excess of 4000
Watts. This is due to advanced thermal management in the form of vented die-cast chassis and increased motor
system venting. These measures effectively remove heat from the voice coil, resulting in extremely low-power
compression. The Colossus 18SB exhibits 100 dB sensitivity and can deliver bass down to 35 Hz (-6 dB) in a
200 litre ported enclosure.
+6
-6
-12
-18
-24
-30
-36
0
dB
Hz
5 10 50 100
500
1k
5k
10k
20k
200
100
20
10
5
2
1
50
Ohms
Hz
20 50 100
200
500
1k 2k
5k
10k
20k
+120
+110
+100
+90
+80
+70
+60
+50
dBr
Hz
20 50 100
200
500
1k 2k
5k
10k
20k
PROFESSIONAL SERIES
COLOSSUS 18SB
COLOSSUS 18SB