crest performance LQ12 LOUDSPEAKER User manual

Specifications LQTM12 Loudspeaker
Crest Audio Inc.
16-00 Pollitt Dr. Fair Lawn, NJ 07410 USA
TEL: [phone] FAX: [phone]
www.crestaudio.com
*80304797*
Crest Audio reserves the right to make improvements in manufacturing or design which may affect specifications.
8/21/01
v.1.5
Architects’ & Engineers’ Specifications:
The loudspeaker system shall have an operating bandwidth of 76 Hz to 18 kHz. The nominal output level shall be 99 dB when
measured at a distance of one meter with an input of one Watt. The nominal impedance shall be 8 Ohms. The maximum
continuous power handling shall be 500 Watts, maximum program power of 1,000 Watts and a peak power input of at least 2,000
Watts, with a minimum amplifier headroom of 3 dB. The nominal radiation geometry shall be 90 degrees in the horizontal plane
and 45 degrees in the vertical plane. The outside dimensions shall be 23.65 inches high by 17.75 inches wide by 14.00 inches
deep. The weight shall be 45 pounds. The loudspeaker system shall be a Crest model LQ 12.
Full Range
Other LQ series loudspeakers
SERIES
Features Description
• Quadratic Throat Geometry horn
• 1000 W program, 2000 W peak
• 12" cast frame 4" VC woofer
• Crest HF™2 two-inch titanium compression driver
• DPS™ (Dynamic Protection System) tweeter protection
• Crossover EQ switch
• High power crossover components
• Top and bottom flying point inserts
• Multiple handles and 1-3/8" stand mount
• Available in White
The Crest LQ 12 is an injection-molded two-way speaker system,
engineered in the Crest tradition to provide superior performance
from a compact and durable package. The enclosure is made from
very high impact injection-molded polypropylene in a trapezoidal
shape, with extensive ribbing and bracing. The grille is comprised of
perforated metal protected by a high quality vinyl coating process.
The two-way system is comprised of a 12" cast frame premium
woofer with a 4" voice coil, and a water-resistant treated cone and
dust cap for superior environmental stability. Capable of over 500 W
of continuous power handling (AES Std 2-1984). The high frequen-
cies are handled by a Crest HF™2 two-inch titanium diaphragm com-
pression driver utilizing ferrofluid, coupled to a 1" Quadratic Throat
Geometry horn, molded integral to the cabinet. This horn provides
outstanding dispersion coupled with a well-controlled pattern, and a
smooth, even response. Utilizing Quadratic Throat Horn technology,
under US Patent 6,059,069, the horn has lower distortion than many
popular CD horn geometries. The Crest HFTM2 driver utilizes the
Radialinear Planar Phase Correction System, under US Patent
6,064,745, which provides smoother and extended high frequency
response.
Input connection to the system is made via two 1/4" phone jacks, and
two 4-pin Neutrik® jacks all connected in parallel are provided for sig-
nal input and daisy chaining capability, while a 4-pin Neutrik switching
jack is provided for bi-amping flexibility while maintaining signal
integrity.
The internal passive crossover features the DPS™ Dynamic
Protection System tweeter protection circuit, and an advanced topol-
ogy with high performance components, to provide high power han-
dling and reliability. The crossover provides driver roll-off and protec-
tion, as well as driver EQ for the woofer and horn. The optimal inte-
gration of the crossover with the selected drivers results in a smooth
frequency response from 76 Hz to 18 kHz. An EQ contour switch is
provided enabling the user to select one of two EQ settings. One set-
ting will yield a nominally flat frequency responce, the other reduces
the upper mid range frequencies which can help in keeping bright
rooms from overloading, or to help achieve a mellower voicing for
those applications that prefer it, such as DJ use.
LQTM12
Loudspeaker
LQ12
LQ10
LQ15
500W
250W
500W
2,000W
1,000W
2,000W
Power Handling Continuous Peak
frequency response
usable low frequency limit (-10 dB point)
power handling
sound pressure level
maximum sound pressure level (1 meter)
radiation angle measured
transducer complement
box tuning frequency
crossover frequency (internal passive)
recommended minimum active crossover
time offset
impedance (Z)
input connections
enclosure materials and finish
mounting provisions
dimensions (H x W x D)
net weight
76 Hz to 18 kHz ±3 dB
54 Hz
Full-range 500 W continuous 1,000 W program
High freq 60 W continuous 120 W program
Full range 99.0 dB SPL, (2.83 V input)
High freq 110.0 dB SPL, (2.83 V input)
Full range 125.0 dB SPL continuous 134.0 dB SPL peak
High freq 127.0 dB SPL continuous 133.0 dB SPL peak
90ohorizontal X 45overtical
Low freq 1x 12" woofer, vented
High freq 0.875 in. exit/51 mm voice coil HF™2 compression driver on a CD horn
Fbox 68 Hz
Low freq High freq 1800 Hz
Low freq High freq 1800 Hz at 12 dB/octave
Low freq 0.00 ms High freq 0.00 ms horn spatially aligned
Full range nominal 8.0 Ωminimum 5.8 Ω
High freq nominal 8.0 Ωminimum 5.4 Ω
2x 1/4" phone jacks paralleled with
2x Neutrik®NL4 Speakon®for full-range inputs.
1x Neutrik NL4S switching Speakon for bi-amp inputs.
Dark gray high-impact polypropylene 1/4" thick finished in molded textured finish
(8) 1/4"-20 threaded mounting points, four each top and bottom
Front 23.65 in. x 17.75 in. x 14.00 in. 601 mm x 451 mm x 356 mm
Rear 22.25 in. x 10.00 in. x 14.00 in. 565 mm x 254 mm x 356 mm
45 lbs. (20.5 kg)
LQ12 Loudspeaker

Specifications LQTM12 Loudspeaker Specifications LQTM12 Loudspeaker
Horizontal Polars
Vertical Polars
-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o
-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o-90o
-60o
-30o
0o
30o
60o
90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
0o
30o
60o
90o
-30o
-60o
-90o
125 Hertz 250 Hertz 500 Hertz 1000 Hertz
2000 Hertz 4000 Hertz 8000 Hertz 16000 Hertz
125 Hertz 250 Hertz 500 Hertz 1000 Hertz
2000 Hertz 4000 Hertz 8000 Hertz 16000 Hertz
Power Handling
There are many different approaches to
power handling ratings. Crest rates this
loudspeaker system’s power handling
using a full-range form of the AES
Standard 2-1984. Using audio band 20
Hz to 20 kHz pink noise with peaks of
four times the RMS level, this strenuous
test signal assures the user that every
portion of this system can withstand
today’s high technology music. This rat-
ing is contingent upon having a mini-
mum of 3 dB of amplifier headroom
available.
Frequency Response
This measurement is useful in determin-
ing how accurately a given unit repro-
duces an input signal. The frequency
response of the Crest LQ 12 is meas-
ured at a distance of 1 meter using a 1
Watt (into the nominal impedance)
swept-sine input signal. As shown in fig-
ure 1, the selected drivers in the Crest
LQ 12 combine to give a smooth fre-
quency response from 76 Hz to 18 kHz.
Directivity
Beamwidth is derived from the -6 dB
points from the polar plots (see figure 3)
which are measured in a whole space
anechoic environment. Q and Directivity
Index are plotted for the on-axis meas-
urement position. These are specifica-
tions that provide a reference to the cov-
erage characteristics of the unit. These
parameters provide insight for proper
placement and installation in the chosen
environment. The blending of the com-
ponents of the Crest LQ 12 exhibit a
desirable beamwidth and directivity (fig-
ure 3 and 4) suitable for sound rein-
forcement applications.
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
1
10
100
Q&DirectivityIndex
Q
Figure4
20
10
Di
0
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
30
40
60
80
100
140
180
300
360
B eam w idth(Degrees)
B eam w idth
Vertical
Horizontal
Figure3
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
1
2
3
5
10
20
30
50
100
Im pedance
Z
()
Figure2
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
60
70
80
90
100
110
dB SPL (re20 Pa)
Amplitude R esponse (1W 1m O n-Axis)
EQ
Normal
Sw itch P osition
Figure1