EAW Cinema MC4972A User manual

One Main Street, Whitinsville, MA 01588 • [phone] • FAX [phone] • Email [email protected] • Web http://www.eaw.com
EAW products are continually improved. All specifications are therefore subject to change without notice. • PUB# MC4972A/2/22/97 • Printed In USA
CINEMA SERIES
Technical Specifications MC4972A
PRELIMINARY INFORMATION
PRODUCT INFORMATION
The MC4972A asymmetrical full-range stage/screen loudspeaker
system brings the future of cinema audio – 3-way loudspeaker design
– to the largest premier exhibition spaces. It is intended for use as
a right- or left-channel loudspeaker in a three- or five-channel sound
system.
Its asymmetrical mid and high frequency horns let the total
loudspeaker system be placed flush to a back wall while still focusing
its output to the audience area ensuring even coverage. The
enclosures can be inverted to provide a right or left-handed angle.
This system provides extremely high output and must be powered by
a minimum of three power amplifiers (triamplification).
The MC4972A combines many of EAW’s breakthrough technologies
including the mathematically correct mid/bass horn with phase/
displacement plug, the Tuned Dipolar Array and the "short-throat"
high frequency horn.
The three enclosure system includes two low frequency systems
separated by a single mid frequency enclosure. The upper LF
enclosure also houses the high frequency system.
Three-way design dramatically advances cinema audio quality by
improving the naturalness and intelligibility of dialog, eliminating
distortion from excessive driver excursion and extending pattern
control into the lower octaves.
The low frequency subsystems employ slot loading of each 15-in
driver pair to create Tuned Dipolar Arrays separated vertically to
provide optimal LF pattern control at 300 Hz. Optimally tuned
enclosure venting increases LF response while limiting driver excur-
sion. This method produces less distortion and minimizes driver
strain while extending LF response to the lowest octaves.
The MC4972’s dedicated midrange frequency subsystem solves many
of cinema audio’s long standing problems. Moving crossover points
out of the vocal region eliminates the acoustical anomalies which
degrade the naturalness and intelligibility of dialog. EAW’s complex,
mathematically correct MF horn with phase plug drastically reduces
the horn-throat cancellation distortion typical of two-way cinema
loudspeakers. And by dividing the mid/high material between two
horn-loaded subsystems, pattern control over the entire frequency
range is enhanced.
The HF element - an HK294A asymmetrical HF system mounted
within the upper LF enclosure - features a 2-in exit compression
driver loaded with a short-throat 90°x 40°HF horn ensuring even
distribution of HF information throughout the auditorium.
The high power input signals require the use of two-terminal barrier
strip input connectors to create gas-tight connections, minimizing
corrosion and maximizing signal transfer. The barrier strips
accomodate bare wire, tinned leads or spade lugs. Each enclosure is
provided with its own input connector. Input for the HF section is
MC4972A
exp 3/2/97 mka ALL DIMENSIONS ARE IN INCHES UNLESS OTHERWISE NOTED.
RIGHT SIDELEFT SIDE
TOP/BOTTOM
REAR
FRONT
(con't.)

One Main Street, Whitinsville, MA 01588 • [phone] • FAX [phone] • Email [email protected] • Web http://www.eaw.com
EAW products are continually improved. All specifications are therefore subject to change without notice. • PUB# MC4972A/2/22/97 • Printed In USA
CINEMA SERIES
Technical Specifications MC4972A
PRELIMINARY INFORMATION
DESCRIPTIVE DATA
Part Number 999499
LF Subsystem & Loading 4 x 15" vented
MF Subsystem & Loading 2 x 10" horn loaded
HF Subsystem & Loading 1 x 2" exit compression driver
on CD horn
Number of Audio Bands 3-way
Type of Audio Bands Full Range
Powering Mode tri-amp
System Crossover active
Controls (switches, knobs) none
Recommended High-Pass
Frequency (24 dB/Octave) 30 Hz
Cabinet Type (shape) rectangular
Enclosure Materials 15mm Baltic Birch Plywood
Finish Flat Black
Connectors 4 x 2 terminal barrier strip
NOMINAL DATA
Frequency Response (Hz)
±3 db 35 Hz - 18 kHz
Efficiency / Axial Sensitivity (dB SPL/1 Watt/1m)
LF 101
MF 109
HF 112
Impedance (Ohm)
LF 2 x 4 Ohms
MF 4
HF 12
Power Handling (Watts)
LF AES Standard 3200
MF AES Standard 600
HF AES Standard 200
Calculated Maximum Output (dB SPL)
LF Peak 142.1
MF Peak 142.8
HF Peak 141.0
LF Long Term 136.1
MF Long Term 136.8
HF Long Term 135.0
Nominal Coverage Angle / -6 dB points (degrees)
Horizontal 90 (assymetrical )
Vertical 40
Recommended Complementary Systems
Sub SB184C, SB185C, SB284C
Dimensions
Height 80.13 in 2035 mm
Width 36 in 914 mm
Depth 30.5 in 775 mm
Weights
Net Weight 525 lb 238.9 kg
Shipping Weight 570 lb 259.4 kg
located on the input panel of the enclosing LF system. The input
panels are located on the sides of the enclosures for convenient
access in cramped installation areas.
All external components feature a “dead” flat black finish to
eliminate the reflection of light through perforated cinema screens.
COMPONENTS & CONSTRUCTION
The MC4972A is a triamplified, three-way, very high-output, full
range loudspeaker system composed of three asymmetrical enclo-
sures. It is intended for use in behind-screen cinema applications.
Two optimally vented LF enclosures (separated by the MF horn) each
house dual slot-loaded 15-in woofers. Dual horn-loaded 10-in
midrange drivers are housed in a separate MF enclosure. A 2-in exit
compression driver loaded with a 90°x 40°constant directivity horn
is mounted to the upper LF enclosure.
The system requires the use of a three band external active electronic
crossover. Crossover between the LF and MF subsystems is recom-
mended to be 350 Hz. Crossover between the MF and HF subsystems
is recommended to be 1.8 kHz.
The high power input signals require the use of two-terminal barrier
strip input connectors to create gas-tight connections, minimizing
corrosion and maximizing signal transfer. The barrier strips
accomodate bare wire, tinned leads or spade lugs. Each enclosure is
provided with its own input connector. Input for the HF section is
located on the input panel of the enclosing LF system. The input
panels are located on the sides of the enclosures for convenient
access in cramped installation areas.
The cabinet is constructed of 15mm void-free, 18-ply-to-the-inch,
Baltic birch plywood. Extensive internal bracing is provided to
minimize panel resonance resulting from the large acoustical
energies generated within the enclosure. The enclosure and all
external parts are coated with a flat black polyurethane finish.
The system includes four mounting points on each side of each
enclosure for use with vertical stabilizing bars. The LF enclosures
also include two additional mounting points on each side to accept
optional acoustical baffles.