Crest Audio LH5M LOUDSPEAKER User manual

SERIES
Features Description
• Smooth frequency response characteristics
• 400 Watt continuous rated woofer
• 150 Watt continuous rated compression driver
• 90 degree x 60 degree constant directivity horn with 1" throat
• High power crossover components
• Neutrik Speakon®input connectors, with automatic biamp switching
• Dual-angle cabinet design
• Recessed steel handles with comfortable round handgrip
• Stand adapter for side-fill use
• Heavy gauge metal grill with black, powder-coat finish
• Rugged stand adapter
• Exterior grade 3/4", 7-ply all poplar APA-1 plywood
• Scuff and weather resistant, black Hammer-Head™finish
The Crest Audio LHTM5M is a newly designed, two-way stage monitor
comprised of one 12" high power woofer, one 1" exit compression
driver coupled to a 90° x 60° constant directivity horn.
As with all LHTM full-range speakers, this unit can be driven in full-
range or biamp mode simply by plugging into the desired jack on the
input plate. The LHTM5M cabinet has a dual-angle back for use in long
and short throw applications. This shape also greatly reduces the
build-up of internal standing waves. Standing waves are internal
amplitude peaks that occur due to reflections within the cabinet at fre-
quencies related to the internal dimensions of the cabinet. This
ensures a minimum of mid-bass and mid-range coloration of the
reproduced sound due to standing waves within the cabinet.
Additionally, a stand mount adapter is included for easy side-fill appli-
cations.
The LHTM5M is constructed of very high quality 3/4", 7-ply all-poplar
plywood, which is void-free, medium density and warp-resistant. The
LHTM5M cabinet is finished with Crest Audio’s durable black Hammer-
Head poly-coating. Polymer corners are also included to provide fur-
ther protection to the cabinet. A black, powder-coated, heavy-gauge
metal grill covers the entire front of the monitor to protect the drivers
from unforeseen impacts.
Crest Audio’s protection circuit for mid and high frequency driver pro-
tection is included as a standard feature. The input signal is routed
through the protection circuit in both full-range and bi-amp modes of
operation. When the high frequency drive level to the LHTM5M exceeds
predetermined thresholds, the protection circuit is temporarily
engaged. This subtly decreases the signal level applied to the high
frequency driver so that it will not be damaged due to long-term over-
powering. High amplitude, short duration transients will not be atten-
uated by the protection circuit and thus have the potential to damage
the driver. The protection circuit is realized through the use of a
dynamically resistive component in conjunction with a switched
padding circuit.
LHTM5M
Loudspeaker
Full Range
Other LH series loudspeakers
LHTM5M
LHTM1
LHTM2
LHTM3
LHTM4
LHTM6M
LHTM7M
400W
600W
1,000W
500W
1,200W
500W
1,000W
800W
1,200W
2,000W
1,000W
2,400W
1,000W
2,000W
1,600W
2,400W
4,000W
2,000W
4,800W
2,000W
4,000W
Power Handling Continuous Program Peak

Specifications LHTM5M Loudspeaker
Power Handling
There are many different approaches to
power handling ratings. Crest Audio rates
this unit’s system power handling using a
modified form of the AES Standard 2-
1984. Utilizing audio band limited (20 Hz -
20 kHz) pink noise with peaks over four
times the RMS level, this strenuous test
signal assures the user that every portion
of this system can withstand high inpact
music. The test signal contains large
amounts of low frequency energy, effec-
tively simulating the frequency content of
live music situations. High frequency test
signals expose the speaker system to
synthesized tones that may extend
beyond audibility. This rating is contingent
on having a minimum of 3 dB of amplifier
headroom available so as to ensure that
clipping does not occur.
Frequency Response
This measurement is useful in determin-
ing how accurately a given unit repro-
duces an input signal. The frequency
response of the LH 5M (Figure 1) is meas-
ured at a distance of 1 meter using a 1
Watt (into the nominal impedance) swept-
sine input signal.
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
70
80
90
100
110
dB SPL (re 20 Pa)
Amplitude Response (1W 1m On-Axis)
Figure 1
20 50 100 200 500 1k 2k 5k 10k 20k
Frequency (Hz)
1
2
3
5
10
20
30
50
100
Impedance
Z
()
Figure 2

Specifications LHTM5M Loudspeaker
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
dimensions (H x W x D)
net weight
LHTM5M Loudspeaker
58 Hz to 18 kHz ±3 dB
45 Hz
Full Range 400 W - 56.6 V RMS 800 W program 1,600 W peak
passive high freq 150 W - 34.6 V RMS 300 W program 600 W peak
Full Range 96.0 dB SPL, (2.83 V input)
high freq106 dB SPL, (2.83 V input)
Full Range 125.2 dB SPL continuous 131.2 dB SPL peak
High Freq 127.5 dB SPL continuous 133.5 dB SPL peak
90 degrees horizontal x 60 degrees vertical
Low Freq 1x 12" woofer, vented basket
High Freq 1.0" Exit / 44 mm voice coil compression driver on a CD horn
Fbox 55 Hz
Low Freq High Freq - 2,000 Hz
Low Freq High Freq - 1,200 Hz @ 12 dB/octave
Low Freq 0.00 ms
High Freq 0.00 ms
Full Range Nominal 8.0ΩMinimum - 7.3Ω
High Freq Nominal 8.0ΩMinimum - 10Ω
2x Neutrik Speakon
4 conductor input jacks
1x Neutrik Speakon 4
conductor biamp switching input jack
3/4”, 7-ply premium, exterior grade, all-poplar, void-free plywood. Material con-
forms to APA-1 specification. Finished in black, Hammer-Head poly-coating.
front 27.0”x 16.0”x 15.5”686 mm x 406 mm x 394 mm
rear 27.0”x 16.0”x 15.5”686 mm x 406 mm x 394 mm
60 Lbs. (27.3 kg)
Architects’ & Engineers’ Specifications:
The loudspeaker system shall have an operat-
ing bandwidth of 58 Hz to 18 kHz. The nomi-
nal output level shall be 96.0 dB when meas-
ured at a distance of one meter with an input
of one Watt. The nominal impedance shall be
8.0 Ohms. The maximum continuous power
handling shall be 400 Watts, maximum pro-
gram power of 800 Watts and a peak power
input of at least 1,600 Watts, with a minimum
amplifier headroom of 3 dB.
The nominal radiation geometry shall be 90
degrees in the horizontal plane and 60 degrees
in the vertical plane. The outside dimensions
shall be 27.0 inches high by 16.0 inches wide by
15.5 inches deep. The weight shall be 60
pounds. The loudspeaker system shall be a
Crest Audio model LHTM5M.

Crest Audio Inc.
16-00 Pollitt Dr. Fair Lawn, NJ 07410
TEL: [phone] FAX: [phone]
www.crestaudio.com
*80304810*
Crest Audio reserves the right to make improvements in manufacturing or design which may affect specifications.
8/22/01
v.1.5