Features
• Two-way, bi-amplified screen channel system
• HF-75 provides 90° horizontal by +20° to -30° vertical coverage
• LF-4215 is constructed of MDF and features single woofer chambers
• Low-distortion waveguide provides highly articulate dialogue
• Shallow depth (20") facilitates installation
Developed specifically for the unique requirements
of professional motion picture playback, the SC-422
extends QSC's commitment to the cinema market. As
a member of the DCS Digital Cinema Speaker Series,
the SC-422 is a two-way, bi-amplified screen channel
loudspeaker system comprised of two main units—the
HF-75 high-frequency system and the LF-4215 low-
frequency system.
The HF-75 high-frequency system features a large
format, 3" (75mm) titanium diaphragm compression
driver mounted on a custom designed high-frequency
cinema horn with an adjustable pan and tilt bracket.
The HF-75 includes a driver protection and equalization
network. DC blocking capacitors protect against DC or
low-frequency signals that would likely destroy an
unprotected driver. Power limiter circuitry protects the
driver from overpowering and a response correction
filter smoothes the frequency response of the horn/
driver combination. The driver and equalization
network provides for more reliable operation, ensuring
the show will go on.
The LF-4215 dual 15" (381mm) low-frequency
enclosure is designed specifically to address the
extended low-frequency response required for cinema
applications. The LF-4215 covers the frequency range
from 35 Hz to 1000 Hz, depending upon the
high-frequency system requirements. Close Coupled
Woofers (CCW), with their tight spacing between
woofers, improves coupling and keeps coverage
angles wide over a greater frequency range than more
widely spaced designs.
The SC-422 is designed for ease of installation.
The HF-75 components come pre-assembled to
reduce field assembly time. Three bolts are all that
are required to secure the HF-75 to the top of the
LF-4215 enclosure.
Specifications
Nominal Coverage
Frequency Range
Crossover Frequency
Impedance
Sensitivity 1 watt /1 meter,
half space
1
Maximum Input Power
8 hours of 6 db crest factor
IEC 268 noise spectrum
2 hours of 6 db crest factor
pink noise, 50 Hz - 20 kHz,
AES method
Recommended Amplifier Power 1600 W RMS maximum
Recommended Processing
Connectors
Transducers
Enclosure
Dimensions (HWD)
Weight - Net
System Weight
Baffle Cut-Out
1) Maximum input power tested in accordance with IEC 268-5 recommendations, 50 Hz - 20 kHz band limiting, 6 dB signal crest factor.
SC-422
Cinema Loudspeaker System
SC-422
90° horizontal x +20 to -30° vertical
38 Hz - 16 kHz (-6 dB)
700 Hz, 24 dB per octave
LF-4215
4Ω
99.5 dB
800 W RMS
1000 W RMS
Subsonic filter below 30 Hz,
> 18 dB per octave
Barrier strip screw terminals
accept up to #10 AWG stranded
wire, four terminals; two inputs
and two parallel outputs
Two 15" (381mm) high efficiency,
extended bass woofer featuring
4" copper voice coils
Quasi B4 alignment, ported
enclosure with fully flared ports,
symmetrical port design, tuned to
36 Hz, constructed of MDF and
heavily braced. Features vandal
resistant woofer mounting bolts
36" x 30" x 20.3"
(910 mm x 762 mm x 516 mm)
172 lbs (78 kg)
212 lbs (96.4 kg)
53" x 32"
HF-75
8Ω
107.5 dB
60 W RMS
80 W RMS
100 W RMS maximum
4th order LR crossover at 1000 Hz
Barrier strip screw terminals
accept up to #10 AWG stranded
wire, four terminals; two inputs
and two HF outputs
1.5" (38mm) exit, 3" titanium
diaphragm compression driver
Tilt/Pan Bracket
±10° vertical tilt
±10° horizontal pan
16" x 30" x 20"
(406 mm x 762 mm x 508 mm)
40 lbs (18.4 kg)