Electro-Voice MH6040AC EDS User Manual
MH6040AC
Coaxial ConstantDirectivity Manifold
Technology® Horn System
• For high-performance speech and
music systems in large venues,
indoors and out
• Includes HP640 high-frequency horn
and mounting brackets
• Midrange covered by two 10-inch
DL10X-SH drivers manifolded on a
60° x 40° constant-directivity horn.
• Response to 100 Hz eliminates
supplemental low-frequency systems
in many applications
• Large mouth has high directivity at
low frequencies
• Ring-Mode Decoupling (RMD™) for
outstanding intelligibility
Description
The Electro-Voice MH6040AC is a widerange, 60° x 40° mid-bass/high-frequency
constant-directivity horn-and-driver system.
With a contractor-installed high-frequency
driver, it covers the frequency range of 100
Hz to 20,000 Hz with minimal equalization.
The MH6040AC combines two world-pioneering concepts developed by ElectroVoice: constant-directivity horns and Manifold Technology
tentially high acoustic output, stable directional characteristics, and extended lowfrequency performance make it highly suitable for music and speech reinforcement in
large indoor and outdoor venues.
At the heart of the MH6040AC are two
DL10X-SH 10-inch water-resistant drivers
(U.S. Patent No. 4,547,632). The driver has
been specially developed for the MH series
of horns. It incorporates a unique diaphragm
construction of Kevlar
combination of high-technology materials
produces a diaphragm with a strength-toweight ratio on the order of twice that of
conventional materials. Each driver is integrally mounted to the fiberglass horn bell via
a heavy-duty mounting bracket and propri-
______________
1. Kevlar® is a registered trademark of Du Pont.
®
. The MH6040AC’s po-
®
and epoxy.1 This
etary Aperiodic Enhancer
Manifolding allows the output of two or more
drivers to be summed without the usual detrimental interference problems in the passband. There are a number of additional advantages to manifolding, including reduced
distortion (see Figure 5) and increased efficiency at certain frequencies. There is also
redundancy built into the system; in the unlikely event of a driver failure, one remains
available. The DLX10-SH drivers are contained and sealed within fiberglass covers
optimally tuned for maximum low-end performance and displacement control.
The frequencies above 1,250 Hz are handled
by the Electro-Voice HP640 constantdirectivity horn, in combination with a contractor-selected-and-installed high-frequency compression driver.
Ring-Mode Decoupling (RMD™)
Technology
The MH6040AC controls both acoustical
and mechanical ring modes to provide dramatically increased intelligibility, using techniques learned from the development of the
Electro-Voice X-Array concert speakers.
There is much less coloration of the sound
from resonating sources, leaving only the
TM
phase plug.
intended sound to be heard by the audience.
Installation
The MH6040AC is designed to be suspended
safely and easily. The integral mounting
brackets at the rear should be used as the
main structural hanging location. There are
also two structural hanging locations on the
rear of the front flange to aim and stabilize
the device. Electro-Voice recommends that
each MH6040AC be independently supported. The MH6040AC can be easily suspended with either the 60° or the 40° coverage pattern horizontal. Note: the contractorselected high-frequency drivers contribute to
the overall weight of the MH6040AC. In the
worst case (DH2A/4MT) an additional 48
lb is added. This should be taken into consideration when suspending the system.
It is recommended that the MH6040AC be
mounted with the horn mouth angled at least
10 degrees down from horizontal. This will
prevent any water that may get into the mouth
of the horn from being funneled to the area
of the woofers.
Electrical connections can be made using
standard electrical boxes or weather-resistant boxes if used in adverse conditions. The
mounting brackets incorporate a predrilled
MH6040AC Coaxial Constant-Directivity Manifold Technology
Horn System
flange to aid electrical box mounting.
If the MH6040AC is suspended, it is recom-
mended that the unit be inspected at least
once a year. If any sign of weakness is detected, remedial action should be taken immediately.
Equalization and Subpassband
Protection
Horn System
The MH6040AC’s mid-bass section exhibits typical constant-directivity horn characteristics, i.e., roll-off at the frequency extremes. At higher frequencies, the roll-off approximately matches the power-response of
the DL10X-SH (6 dB per octave). At lower
frequencies, directivity is lost when the
mouth is no longer large enough to maintain
directional control. These two consequences
can be observed in the “humped” response
in Figure 3. Equalization can be easily applied with a graphic equalizer to give a flat
response.
The high-frequency compression driver can
be equalized with a graphic equalizer or an
EQ module inserted into the Electro-Voice
XEQ-2 (two-way) or XEQ-3 (two-way or
three-way) active crossover/equalizer. The
EQ module should be selected to suit the
particular compression driver and the HP640
horn (see relevant data sheet). Because of
its use in large arenas, where air loss can be
significant, it is recommended that the system be equalized “on site” for optimum re-
MH6040AC Coaxial Constant-Directivity Manifold Technology
sults. The XEQ-3 and the mid-bass EQ module from the EQMT-2 can be used to provide a good starting point for the equalization.
Electro-Voice strongly recommends the use
of a 100-Hz high-pass filter to protect the
drivers from unnecessary excursion and thermal stress.
Directivity
The axial directivity factor R
MH6040AC was computed at each of the
one-third-octave center frequencies over the
frequency range noted from the horizontal/
vertical polars shown in Figure 7. Directivity index (D
) was taken over the same fre-
i
quency range.
of the
q
Beamwidth
Plots of the MH6040AC’s 6-dB-down total
included beamwidth angles are shown in Figure 6 for each of the one-third-octave center
frequencies noted.
Polar Response
The directional characteristics of the
MH6040AC were obtained by selecting the
horizontal and vertical details from a full set
of polar data measured in EV’s large
anechoic chamber. The measurement microphone was placed 6.1 m (20 ft) from the center of rotation of the horn which, in turn, is
0.94 m (3.08 ft) behind the mouth of the horn.
See Figure 1.
Polarity of the DL10X-SH Drivers
For Manifold Technology
®
to operate correctly, the drivers must be operated “in
phase.” In other words, for parallel connection, the DL10X-SH’s must be connected so
the negative terminals of the drivers are connected together, and the positive terminals
are connected together.
Service
In the unlikely event the MH6040AC requires service, each DL10X-SH easily can
be replaced or serviced by removing the back
cover and then removing the driver. A service data sheet is available from ElectroVoice.
Power Handling Capacity
To our knowledge, Electro-Voice was the
first U.S. manufacturer to develop and publish a power test closely related to real-life
conditions. A random-noise input signal is
used because it contains many frequencies
simultaneously, just like real voice or instrument program. The signal contains more
energy at extremely high and low frequencies than typical actual program, adding an
extra margin of reliability . The test combines
not only the overall “long-term average” or
“continuous” level—which our ears interpret
as loudness—but also short-duration peaks
which are many times higher than average,
just like actual program. The long-term average level stresses the speaker thermally
(heat). The instantaneous peaks test mechanical reliability (cone excursion). Note that the
sine-wave test signals sometimes used have
a much less demanding peak value relative
to their average level. In actual use, longterm average levels exist from several seconds on up. The test performed lasts for eight
hours, adding another extra level of confidence.
Specifically, the MH6040AC mid-band section is designed to withstand the power test
described in EIA Standard RS-426A. The
EIA test spectrum is applied for eight hours.
The spectrum is obtained by filtering white
noise (a particular type of random noise with
equal energy per bandwidth). The filter applies 6-dB-per-octave slopes below 40 Hz
and above 318 Hz. When measured with a
one-third-octave constant-percentage analyzer, this filter produces a spectrum whose
3-dB-down points are at 100 Hz and 1,200
Hz with a 3-dB-per-octave slope above 1,200
Hz. This shaped signal is then further filtered
with an 80-Hz, 12-dB-per-octave high-pass
filter to prevent out-of-passband displacement. The amplifier is set to provide 600
watts into the 3.45-ohm EIA equivalent impedance (45.5 volts). Amplifier clipping sets
instantaneous peaks at 6 dB above the continuous power or 2,400 watts peak (91.0
volts). During this test, the mid-band section is not high passed at 1,250 Hz. The highfrequency section’s power handling is dependent on the selected driver combination.
Please refer to the relevant engineering data
sheet.
Architects’ and Engineers’
Specifications
The horn shall be of the constant-directivity
type. It shall produce a horizontal beamwidth
(6-dB-down angle) of -60°, deviating no
more than +10° or –20° from this angle over
the range of 400 Hz to 20 kHz. It shall produce a vertical beamwidth of 40°, deviating
no more than +20° or –15° over the frequency range of 325 Hz to 20 kHz. In addition, it shall provide an acoustic load to below 100 Hz.
The MH6040AC mid-bass section shall operate over the range of 100 Hz to 4,000 Hz,
with a recommended crossover frequency of
2
MH6040AC Coaxial Constant-Directivity Manifold Technology
Horn System
1,250 Hz, and be driven by two 10-inch,
weather-resistant drivers with high-technology cones of Kevlar
ented Manifold T echnology
®
and epoxy.1 The pat-
®
technique shall
be exploited and result in a power-handling
capacity of 600 watts per EIA Standard RS-
426. The average axial sensitivity shall be
105 dB SPL at 1 meter with 2.83 volts applied. The frequencies above 1,250 Hz shall
be produced by the supplied Electro-Voice
HP640 TransPlanar
TM
constant-directivity
horn with user-selectable driver combinations.
The horn bell manifold chamber and back
covers shall be constructed of fiberglass,
foam and polyester resin. Two steel mounting rails shall be provided to coaxially mount
the Electro-Voice HP640 horn. The horn
shall have an integral rear mounting bracket
made of black powder-coated 10-gauge steel.
Brackets shall be provided at the front of the
horn to stabilize and aim the MH6040AC.
The horn shall be 149.9 cm (59.0 in.) high,
99.1 cm (39.0 in.) wide, 153.4 cm (60.4 in.)
long and weigh 75 kg (165 lb).
The horn shall be the Electro-Voice
MH6040AC coaxial constant-directivity
Manifold Technology
®
horn.
Limited Warranty
Electro-Voice products are guaranteed
against malfunction due to defects in materials or workmanship for a specified period,
as noted in the individual product-line
statement(s) below, or in the individual prod-
uct data sheet or owner’s manual, beginning
with the date of original purchase. If such
malfunction occurs during the specified period, the product will be repaired or replaced
(at our option) without charge. The product
will be returned to the customer prepaid. Ex-
clusions and Limitations: The Limited
W arranty does not apply to: (a) exterior finish or appearance; (b) certain specific items
described in the individual product-line
statement(s) below, or in the individual product data sheet or owner’s manual; (c) malfunction resulting from use or operation of
the product other than as specified in the
product data sheet or owner’s manual; (d)
malfunction resulting from misuse or abuse
of the product; or (e) malfunction occurring
at any time after repairs have been made to
the product by anyone other than ElectroVoice Service or any of its authorized service
representatives. Obtaining Warranty Ser-
vice: To obtain warranty service, a customer
must deliver the product, prepaid, to Electro-Voice Service or any of its authorized
service representatives together with proof
of purchase of the product in the form of a
bill of sale or receipted invoice. A list of
authorized service representatives is available from Electro-V oice Service at 600 Cecil
Street, Buchanan, MI 49107 (800/234-6831
or FAX 616/695-4743). Incidental and
Consequential Damages Excluded: Product repair or replacement and return to the
customer are the only remedies provided to
the customer. Electro-Voice shall not be liable for any incidental or consequential damages including, without limitation, injury to
persons or property or loss of use. Some
states do not allow the exclusion or limitation of incidental or consequential damages
so the above limitation or exclusion may not
apply to you. Other Rights: This warranty
gives you specific legal rights, and you may
also have other rights which vary from state
to state.
Electro-V oice Speakers and Speaker Systems are guaranteed against malfunction due
to defects in materials or workmanship for a
period of five (5) years from the date of original purchase. The Limited W arranty does not
apply to burned voice coils or malfunctions
such as cone and/or coil damage resulting
from improperly designed enclosures.
Electro-Voice active electronics associated
with the speaker systems are guaranteed for
three (3) years from the date of original purchase. Additional details are included in the
Uniform Limited Warranty statement.
For warranty repair or service information, contact the service repair department
at: 616/695-6831 or 800/685-2606.
For technical assistance, contact Technical
Support at 800/234-6831 or 616/695-6831,
M-F, 8:00 a.m. to 5:00 p.m. Eastern Standard Time.
Specifications subject to change without
notice.
MH6040AC Coaxial Constant-Directivity Manifold Technology
Horn System
3
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