Apogee CRQ-12 Multi-Mode Parametric EQ Spec

CRQ-12
MULTI-MODE
PARAMETRIC EQUALIZER
•
The CRQ-12 parametric equalizer offers a wealth of possibilities for
sonic shaping of large, complex sound systems. The combination of
high-quality filter components and configurable architecture makes
the most difficult equalization task quick and accurate.
The CRQ-12 is a “Multi-Mode” parametric equalizer with three distinct
configurations. In the 6/6 mode the unit functions as two discreet
equalizers with six bands each. Each channel has two independent
outputs with separate level controls and mute switches, 12dB per
octave low cut and high cut filters with adjustable corner frequencies
and low and high frequency shelving filters, each with adjustable
turnover frequencies and the ability to boost as well as cut. The second mode is called 6/12. Utilizing a single input, the A channel outputs are dependent on the settings of the first six bands while the B
channel outputs reflect the settings of all twelve bands. Each channel
retains its two independent level controls as well as low cut, high cut
and low and high shelving controls. In the 12/12 mode both the A and
B channel outputs reflect the settings of all twelve filters, while the two
output sections, with their respective gain controls, band pass and
shelving filters remain independent.
Each parametric band filter is fully adjustable throughout the entire
audio frequency range (20Hz—20kHz), utilizing a three position range
switch. Every band also includes an IN/OUT switch with a corresponding LED indicator. The Boost and Cut controls feature a center
detent at the neutral position (zero boost or cut) and provide a range
of -20 to +15dB. Bandwidth controls allow adjustment over a 1⁄25 to 2
octave range.
The CRQ-12 utilizes extremely high-grade components throughout,
including precision plastic conductor pots, metal film resistors,
polypropylene capacitors, high-grade op-amps specially designed for
audio filter circuits and a rugged steel chassis. A polycarbonate front
panel allows pencil markings with minimal adverse effects. Cooling
for the CRQ-12 is supplied by a variable speed fan for absolute stability of filter settings regardless of ambient temperature. A passive
“hard-wire” bypass level control is utilized on each output to prevent
feedback in the event of power loss.
Six Parametric Bands of
Equalization per Channel
• 6/6, 6/12, 12/12 Multi-Mode
Selectable Operation
• Low Pass, High Pass and
Low & High Freq. Shelving
• Two Outputs per Channel
with Separate Level Controls
• Fan Cooled for Stability
APPLICATIONS
Concert Touring
Musical Theater
Auditoriums & Sports Arenas
Churches
Television Audio Systems
Hotel Meeting & Ballrooms
®
CRQ-12 PARAMETRIC EQUALIZER
CRQ-12 FRONT PANEL
CRQ-12 REAR PANEL
CRQ-12 APPLICATIONS
CRQ-12 PARAMETRIC EQUALIZER
With its unique Multi-Mode operation, the CRQ-12 lends itself to creative
solutions for complex equalization requirements.
Example 1:
In the 6/12 mode, the first six filters feeding the first pair of outputs are used to
equalize a central cluster, “tuning out” the room resonant modes. For ease of
balancing the horizontal coverage, Output 1 feeds the inner speakers and
Output 2 feeds the outer speakers.
The second six filters feeding the second pair of outputs are sent through a
delay line to equalize a group of speakers under a balcony. Since the first six
filters are “carried through” internally to the second set of six filters, all of the
corrections for room resonance are already completed, and the operator still
has six parametric filters left to “tune” the response of the underbalcony
speakers, filling in only those frequencies that are not arriving from the main
cluster.
Finally, the overall tone and “texture” for both the underbalcony area and the
central cluster can be independently adjusted by the low-pass, high-pass and
low and high shelving filters, which remain separate for each of the two
channels.
Example 2:
In the 12/12 mode, all twelve filters are available to equalize a complex central
cluster consisting of an upper row focused on the balcony of a theater and a
lower row focused on the lower seats. All twelve filters are used to precisely
notch out room resonance and reduce feedback from the stage mics. The
lower row of speakers is fed from outputs 1 & 2 which feed the inner and
outer cluster sections. The upper row is fed from outputs 3 & 4, again split
inner and outer. Significant attenuation is required in the low frequencies from
the upper row of speakers to reduce “contamination” of their energy in the
lower seats. This is readily accomplished with the 12dB per octave high pass
filter combined with the low frequency shelving filter on outputs 3 & 4. The
lower row of speakers however, requires broad-band high frequency attenuation to compensate for its closer working distance. This is done with the
shelving filter on outputs 1 & 2. There are still several unused low and high filters remaining to make additional adjustments “to taste”. When critical narrow
band low frequency notches need to be re-aligned for changing conditions, all
of the parametric filters will uniformly affect all four outputs, though again the
low-pass, high-pass and low and high shelving filters on each channel remain
independent.
FREQUENCY RESPONSE
20 Hz — 20 kHz (±0.5 dB)
DISTORTION
<0.003% measured at +21 dBu (1kHz)
CROSSTALK
-80 dBA
OVERLOAD INDICATION
+20 dBu
INPUT CONNECTIONS
3 pin XLR, electronically balanced
INPUT IMPEDANCE
50k ohms, balanced (25k ohms, unbalanced)
OUTPUTS
3 per channel (2 have independent level control, 1 output fixed)
OUTPUT CONNECTIONS
3 pin XLR, electronically balanced
OUTPUT IMPEDANCE
600 ohms, balanced (600 ohms, unbalanced)
MAXIMUM OUTPUT LEVEL
+25 dBu
DYNAMIC RANGE
115 dB
FILTERS
Type — Parametric (via range switch), six bands per channel
Bandwidth — Variable from 1⁄25 - 2 octaves
Cut & Boost — -20 dB, +15 dB
High Cut — 3.2 kHz — 35 kHz, 12 dB per octave
High Frequency Shelving — 670 Hz — 11 kHz, -15 dB, +15 dB
Low Cut — 15 Hz — 200 Hz, 12 dB per octave
Low Frequency Shelving — 40 Hz — 430 Hz, -15 dB, +15 dB
BYPASS LEVEL CONTROL
Passive, one for each output (four total)
MODE SWITCH
Detented — Selects between 6/6, 6/12 and 12/12 modes
COOLING
Variable speed DC fan
GROUND LIFT
Detented recessed switch
FAN CONTROL
Push switch — Locks fan in low-speed mode
INDICATORS
1 green LED per filter (in/out), 1 red LED per output (on/off),
2 color (green/red) LED for signal presence and input overload,
1 green LED for channel ready, 1 green LED for channel in/out,
3 green LEDs for Mode indication (6/6, 6/12, 12/12)
LINE VOLTAGE
Switchable — 100, 120 or 220, 240 VAC, 50/60 Hz
CONSTRUCTION
16 Gauge steel chassis, welded box design
DIMENSIONS
19" (483 mm) wide by 3.5" (89 mm) high (2 EIU rack spaces) by
11.125" (283 mm) deep
WEIGHT
23 lbs. (10.43 kg)
OPTIONS/ACCESSORIES
In the above examples, the innovative Multi-Mode operation of the CRQ-12
performs tasks that cannot be handled by conventional equalizer designs.
®
2180 South McDowell Boulevard, Petaluma, CA 94954 USA
tel. (707) 778-8887 fax (707) 778-6923
Security Cover, Cables
Specifications subject to change without notice
LIMITED WARRANTY
Apogee Sound Inc. products, when sold domestically, are guaranteed for a period of
one year from the date of the original purchase against malfunctions due to defects in
materials and workmanship. If such a malfunction occurs, the product will be repaired
or replaced at our option, without charge, if delivered prepaid to the factory. Product
will be returned prepaid via ground transport. Please see Engineering Data Sheet for
other terms and conditions.
For detailed technical information refer to the
Apogee CRQ-12 Engineering Data Sheet.
© Apogee Sound Inc. 2/93 42-0158
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