Specifications LHTM7M Loudspeaker - Crest Audio
Specifications LHTM7M Loudspeaker - Crest Audio
Specifications LHTM7M Loudspeaker - Crest Audio
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Features Description<br />
• Smooth frequency response characteristics<br />
• 500 watt continuous rated woofer<br />
• 150 watt continuous rated compression driver<br />
• 60 degree x 40 degree Constant Directivity horn with 2" throat<br />
• High power crossover components<br />
• Neutrik Speakon ® connectors with automatic switching bi-amp input<br />
• Dual-angle cabinet design<br />
• Recessed steel handles with comfortable round hand-grip<br />
• Stand adapter for side-fill use<br />
• Heavy gauge metal grill with black powder-coat finish<br />
• High-impact resistant polypropylene cabinet corners<br />
• Rugged stand adapter<br />
• Exterior grade 3/4" 7-ply all Poplar APA-1 plywood<br />
• Scuff and weather resistant, black Hammer-Head finish<br />
LH TM<br />
7M<br />
<strong>Loudspeaker</strong><br />
SERIES<br />
Power Handling<br />
Full Range<br />
Continuous Program Peak<br />
LH TM 7M<br />
Other LH series loudspeakers<br />
LH TM 1<br />
LH TM 2<br />
LH TM 3<br />
LH TM 4<br />
LH TM 5M<br />
LH TM 6M<br />
1,000W<br />
600W<br />
1,000W<br />
500W<br />
1,200W<br />
400W<br />
500W<br />
2,000W<br />
1,200W<br />
2,000W<br />
1,000W<br />
2,400W<br />
800W<br />
1,000W<br />
4,000W<br />
2,400W<br />
4,000W<br />
2,000W<br />
4,800W<br />
1,600W<br />
2,000W<br />
The <strong>Crest</strong> <strong>Audio</strong> LH7M is a newly designed two-way stage monitor<br />
comprised of two 12" high-power woofers, one 2" exit compression<br />
driver coupled to a 60° x 40° constant directivity horn.<br />
As with all LH full-range speakers, this unit can be driven in fullrange<br />
or bi-amp mode simply by plugging into the desired jack on the<br />
input plate. The LH7M cabinet has a dual-angle back for use in long<br />
and short throw applications. This shape also greatly reduces the<br />
build-up of internal standing waves. Standing waves are internal amplitude<br />
peaks that occur due to reflections within the cabinet at frequencies<br />
related to the internal dimensions of the cabinet. This ensures a<br />
minimum of mid-bass and mid-range coloration of the reproduced<br />
sound due standing waves within the cabinet. Additionally, a stand<br />
mount adapter is included for easy side-fill applications.<br />
The LH7M is constructed of very high quality 3/4" 7-ply all-Poplar plywood,<br />
which is void-free, medium density, and warp-resistant.The LH7M<br />
cabinet is finished with <strong>Crest</strong> <strong>Audio</strong>’s durable black Hammer-Head polycoating.<br />
Polymer corners are also added to provide further protection to the<br />
cabinet. A black powder-coated heavy-gauge metal grill covers the entire<br />
front of the monitor to protect the drivers from unforeseen impacts.<br />
<strong>Crest</strong> <strong>Audio</strong>’s protection circuit for mid and high frequency driver protection<br />
is included as a standard feature. The input signal is routed<br />
through the protection circuit in both full-range and bi-amp modes of<br />
operation. When high frequency drive level to the LH7M exceeds<br />
predetermined thresholds, the protection circuit is temporarily<br />
engaged. This subtly decreases the signal level applies to high frequency<br />
driver so that it will not be damaged due to long term overpowering.<br />
Short duration transients will not be attenuated by the protection<br />
circuit and thus have the potential to damage the driver. The<br />
protection circuit is realized through the use of a dynamically resistive<br />
component in conjunction with a switched padding circuit.<br />
An additional feature of the crossover is the use of a new switching<br />
Neutrik Speakon ® connector for the bi-amp input. It is no longer necessary<br />
to manually switch, or move jumpers to reconfigure the<br />
crossover circuitry when bi-amping any of the LH series loudspeakers.<br />
This connector is wired 1+, 1- for the woofer, with 1+ being positive,<br />
and 2+, 2- for the high frequency driver, with 2+ being positive.<br />
As with the full range inputs, simply insert your Speakon bi-amp plug<br />
into the bi-amp input connector, and twist clockwise 1/8 turn. This simple<br />
action switches out the crossover, and simultaneously connects<br />
the woofer and driver directly to the bi-amp speaker cable.
<strong>Specifications</strong> LH TM<br />
7M <strong>Loudspeaker</strong><br />
Power Handling<br />
<strong>Crest</strong> <strong>Audio</strong> rates this unit’s system power<br />
handling using a modified form of the AES<br />
Standard 2-1984. Utilizing audio band limited<br />
(20 Hz - 20 kHz) pink noise with<br />
peaks over four times the RMS level. This<br />
strenuous test signal assures the user that<br />
every portion of this system can withstand<br />
high impact music. The test signal contains<br />
large amounts of low frequency<br />
energy, effectively simulating the frequency<br />
content of live music situations. High<br />
frequency test signals expose the speaker<br />
system to synthesized tones that may<br />
extend beyond audibility. This rating is<br />
contingent on having a minimum of 3 dB<br />
of amplifier headroom available so as to<br />
ensure that clipping does not occur.<br />
Frequency Response<br />
This measurement is useful in determining<br />
how accurately a given unit reproduces<br />
an input signal. The frequency<br />
response of the LH7M (Figure 1) is<br />
measured at a distance of 1-meter using a<br />
1 watt (into the nominal impedance)<br />
swept-sine input signal.<br />
dB SPL (re 20 Pa)<br />
110<br />
100<br />
90<br />
80<br />
70<br />
20 50 100 200 500 1k 2k 5k 10k 20k<br />
Frequency (Hz)<br />
Figure 1<br />
100<br />
50<br />
30<br />
Z<br />
20<br />
( ) 10<br />
5<br />
3<br />
2<br />
Impedance<br />
1<br />
20 50 100 200 500 1k 2k 5k 10k 20k<br />
Frequency (Hz)<br />
Figure 2<br />
Amplitude Response (1W 1m On-Axis)
<strong>Specifications</strong> LH TM<br />
7M <strong>Loudspeaker</strong><br />
frequency response<br />
usable low frequency limit (-10 dB point)<br />
power handling<br />
sound pressure level<br />
maximum sound pressure level (1 meter)<br />
radiation angle measured<br />
transducer complement<br />
box tuning frequency<br />
crossover frequency (internal passive)<br />
recommended minimum active crossover<br />
time offset<br />
impedance Z<br />
input connections<br />
enclosure materials and finish<br />
dimensions (H x W x D)<br />
net weight<br />
Architects’ & Engineers’ <strong>Specifications</strong>:<br />
The loudspeaker system shall have an operating<br />
bandwidth of 59 Hz to 20 kHz. The nominal<br />
output level shall be 97.0 dB when measured<br />
at a distance of one meter with an input of one<br />
watt. The nominal impedance shall be 8.0<br />
ohms. The maximum continuous power han-<br />
LH TM 7M <strong>Loudspeaker</strong><br />
58 Hz to 20 kHz (±3 dB)<br />
47 Hz<br />
Full Range: 1,000 W continuous 89.4 V RMS 2,000 W program 4,000 W peak<br />
passive high freq: 150 W continuous 34.6 V RMS 300 W program 600 W peak<br />
Full Range 97.0 dB SPL, (2.83 V input)<br />
high freq107 dB SPL, (2.83 V input)<br />
Full Range 126.8 dB SPL continuous 132.8 dB SPL peak<br />
High Freq 134.5 dB SPL continuous 140.5 dB SPL peak<br />
90 degrees horizontal x 40 degrees vertical<br />
Low Freq 1x 15" Woofer, vented basket<br />
High Freq 2.0" Exit / 75 mm voice coil compression driver on a CD horn<br />
Fbox 56 Hz<br />
Low Freq High Freq - 1700 Hz<br />
Low Freq High Freq - 1500 Hz at 12 dB/octave<br />
Low Freq 0.00 ms<br />
High Freq 0.60 ms<br />
Full Range Nominal 8.0Ω Minimum 7.1Ω<br />
High Freq Nominal 8.0Ω Minimum 6.8Ω<br />
2x Neutrik Speakon ®<br />
4 conductor input jacks<br />
1x Neutrik Speakon 4<br />
conductor biamp switching input jack<br />
3/4" 7-ply premium, exterior grade, all-poplar, void-free plywood. Material conforms<br />
to APA-1 specification. Finished in black, Hammer-Head poly-coating.<br />
front 30.5" x 219.0" x 17.0" 775 mm x 483 mm x 445 mm<br />
97 Lbs. (44.1 kg)<br />
dling shall be 500 watts, maximum program<br />
power of 1,000 watts and a peak power input<br />
of at least 2,000 watts, with a minimum amplifier<br />
headroom of 3 dB.<br />
The nominal radiation geometry shall be 60<br />
degrees in the horizontal plane and 40 degrees<br />
in the vertical plane. The outside dimensions<br />
shall be 30.5 inches high by 19.0 inches wide by<br />
17.0 inches deep. The weight shall be 97<br />
pounds. The loudspeaker system shall be a<br />
<strong>Crest</strong> <strong>Audio</strong> model LH7M.
<strong>Crest</strong> <strong>Audio</strong> reserves the right to make improvements in manufacturing or design which may affect specifications.<br />
8/22/01<br />
v.1.5<br />
*80304812*<br />
<strong>Crest</strong> <strong>Audio</strong> Inc.<br />
16-00 Pollitt Dr. Fair Lawn, NJ 07410<br />
TEL: 201.909.8700 FAX: 201.909.8744<br />
www.crestaudio.com