L-ACOUSTICS V-DOSC Manual Version 4
6/29/2005
Page 36 of 158
Figure 20: SB218 Subwoofer – Front and Rear Views
With the addition of SB218 subwoofers, the low frequency response of the V-DOSC system is
extended down to 25 Hz. The SB218 subwoofer enclosure has been specifically designed to
complement V-DOSC and all OEM factory presets are optimized for the SB218.
The SB218 contains two 18-inch transducers, front-loaded in an optimally-tuned and vented
enclosure. Power handling is 1100 Wrms continuous program (4400 Wpeak) at a nominal 4 ohm
impedance. Connection is made via Speakon NL4 connector and DOSUB cables are used to connect
to amplifier racks (one SB218 per LA48a amplifier channel). Usable frequency response is 28 to 140
Hz (+/- 3 dB) with -10 dB response at 25 Hz referenced to the average level of the usable response.
The SB218 features critically-damped tuning characteristics with an enclosure tuning frequency of 32
Hz. The central, large-area port enhances large-signal dynamic capability while minimizing non-
linearity due to port turbulence effects.
The 18-inch transducers employed in the SB218 have a 4.5 inch diameter edgewound copper ribbon
voice coil, 9 mm peak excursion capability, weatherproof cone body, diecast aluminum frame, massive
vented magnet structure and utilize advanced high temperature adhesives in their assembly.
Loudspeaker components feature low thermal power compression, long term reliability and low
distortion output.
The SB218 is constructed of 24 mm baltic birch and is internally braced with steel corner plates and
joints that are sealed, screwed and rabbeted in order to remain free of vibration at extreme sound
pressure levels. Dimensions are 550 mm (21.7 in) high, 1300 mm (51.2 in) wide and 700 mm (27.6 in)
deep and enclosure weight is 115 kg (233.7 lbs). The finish is brown gray (RAL8019) structured
polyurethane paint and the front of the enclosure is protected by a black powder-coated, 1.5 mm
thick steel grill grille covered with 10 mm (0.4-in) thick acoustically-transparent open cell foam.
The SB218 has two recessed flytrack sections mounted on both sides for rigging purposes. An
accessory flying bar is available that allows for rigging of arrays up to 8 enclosures deep with greater
than 5:1 safety factor. Six recessed handles are located on the sides of the enclosure and a front
mounted dolly board attaches to the enclosure using two locking pins and two front baffle-mounted
dolly locator studs.
Dimension (WxHxD):
1300mm x 550mm x 700mm
(51.2" x 21.7" x 27.6")
Weight:
106 kg (234 lbs)
Summary of Contents for V-DOSC
Page 1: ...Version 4 June 2005 V DOSC OPERATOR MANUAL ...
Page 2: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 2 of 158 ...
Page 116: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 116 of 158 a b c d e f g h ...
Page 117: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 117 of 158 i j k l m n o p ...
Page 118: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 118 of 158 q r s t u v w x ...
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