Electro-Voice MH6040AC User manual

MH6040AC
Coaxial Constant-
Directivity Manifold
Technology®Horn System
______________
1. Kevlar®is a registered trademark of Du Pont.
• 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 wide-
range, 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-pio-
neering concepts developed by Electro-
Voice: constant-directivity horns and Mani-
fold Technology®. The MH6040AC’s po-
tentially high acoustic output, stable direc-
tional characteristics, and extended low-
frequency performance make it highly suit-
able 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®and epoxy.1This
combination of high-technology materials
produces a diaphragm with a strength-to-
weight ratio on the order of twice that of
conventional materials. Each driver is inte-
grallymountedtothefiberglasshornbellvia
a heavy-duty mounting bracket and propri-
etary Aperiodic EnhancerTM phase plug.
Manifoldingallowstheoutputoftwo or more
drivers to be summed without the usual det-
rimental interference problems in the pass-
band. There are a number of additional ad-
vantages to manifolding, including reduced
distortion (see Figure 5) and increased effi-
ciency at certain frequencies. There is also
redundancy built into the system; in the un-
likely event of a driver failure, one remains
available. The DLX10-SH drivers are con-
tained and sealed within fiberglass covers
optimally tuned for maximum low-end per-
formance and displacement control.
The frequencies above 1,250 Hz are handled
by the Electro-Voice HP640 constant-
directivity horn, in combination with a con-
tractor-selected-and-installed high-fre-
quency compression driver.
Ring-Mode Decoupling (RMD™)
Technology
The MH6040AC controls both acoustical
and mechanical ring modes to provide dra-
maticallyincreasedintelligibility, using tech-
niques 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
intended sound to be heard by the audience.
Installation
TheMH6040AC is designed to besuspended
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 sup-
ported. The MH6040AC can be easily sus-
pended with either the 60° or the 40° cover-
age pattern horizontal. Note: the contractor-
selectedhigh-frequencydriverscontribute to
the overall weight of the MH6040AC. In the
worst case (DH2A/4MT) an additional 48
lb is added. This should be taken into con-
sideration 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
preventany water thatmayget into themouth
of the horn from being funneled to the area
of the woofers.
Electrical connections can be made using
standard electrical boxes or weather-resis-
tant boxes if used in adverse conditions. The
mounting brackets incorporate a predrilled

MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
2
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 de-
tected, remedial action should be taken im-
mediately.
Equalization and Subpassband
Protection
The MH6040AC’s mid-bass section exhib-
its typical constant-directivity horn charac-
teristics, i.e., roll-off at the frequency ex-
tremes.Athigher frequencies, the roll-offap-
proximately 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 ap-
plied 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
particularcompressiondriverand 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 sys-
tem be equalized “on site” for optimum re-
sults.TheXEQ-3andthemid-bassEQmod-
ule from the EQMT-2 can be used to pro-
vide a good starting point for the equaliza-
tion.
Electro-Voice strongly recommends the use
of a 100-Hz high-pass filter to protect the
driversfromunnecessary excursion and ther-
mal stress.
Directivity
The axial directivity factor Rqof the
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. Directiv-
ity index (Di) was taken over the same fre-
quency range.
Beamwidth
Plots of the MH6040AC’s 6-dB-down total
includedbeamwidth angles are shown inFig-
ure 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 micro-
phone was placed 6.1 m (20 ft) from the cen-
ter of rotation of the horn which, in turn, is
0.94m (3.08 ft) behind themouthof the horn.
See Figure 1.
Polarity of the DL10X-SH Drivers
For Manifold Technology®to operate cor-
rectly, the drivers must be operated “in
phase.” In other words, for parallel connec-
tion, the DL10X-SH’s must be connected so
the negative terminals of the drivers are con-
nected together, and the positive terminals
are connected together.
Service
In the unlikely event the MH6040AC re-
quires service, each DL10X-SH easily can
bereplaced or serviced byremovingthe back
cover and then removing the driver. A ser-
vice data sheet is available from Electro-
Voice.
Power Handling Capacity
To our knowledge, Electro-Voice was the
first U.S. manufacturer to develop and pub-
lish 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 instru-
ment program. The signal contains more
energy at extremely high and low frequen-
cies than typical actual program, adding an
extramarginof reliability. The test combines
not only the overall “long-term average” or
“continuous”level—whichour ears interpret
as loudness—but also short-duration peaks
which are many times higher than average,
just like actual program. The long-term av-
erage level stresses the speaker thermally
(heat).The instantaneous peaks testmechani-
cal 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, long-
term average levels exist from several sec-
ondsonup.The test performed lasts for eight
hours, adding another extra level of confi-
dence.
Specifically, the MH6040AC mid-band sec-
tion 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 ap-
plies 6-dB-per-octave slopes below 40 Hz
and above 318 Hz. When measured with a
one-third-octave constant-percentage ana-
lyzer, this filter produces a spectrum whose
3-dB-down points are at 100 Hz and 1,200
Hzwith a 3-dB-per-octave slope above1,200
Hz.Thisshapedsignal is then further filtered
with an 80-Hz, 12-dB-per-octave high-pass
filter to prevent out-of-passband displace-
ment. The amplifier is set to provide 600
watts into the 3.45-ohm EIA equivalent im-
pedance (45.5 volts). Amplifier clipping sets
instantaneous peaks at 6 dB above the con-
tinuous power or 2,400 watts peak (91.0
volts). During this test, the mid-band sec-
tionisnothigh passed at 1,250 Hz. The high-
frequencysection’spowerhandling is depen-
dent 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.Itshall 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 pro-
duce a vertical beamwidth of 40°, deviating
no more than +20° or –15° over the fre-
quency range of 325 Hz to 20 kHz. In addi-
tion, it shall provide an acoustic load to be-
low 100 Hz.
The MH6040AC mid-bass section shall op-
erate over the range of 100 Hz to 4,000 Hz,
with a recommended crossover frequency of

3
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
1,250 Hz, and be driven by two 10-inch,
weather-resistant drivers with high-technol-
ogy cones of Kevlar®and epoxy.1The pat-
entedManifoldTechnology®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 ap-
plied. The frequencies above 1,250 Hz shall
be produced by the supplied Electro-Voice
HP640 TransPlanar TM constant-directivity
horn with user-selectable driver combina-
tions.
The horn bell manifold chamber and back
covers shall be constructed of fiberglass,
foam and polyester resin. Two steel mount-
ingrailsshallbe provided to coaxially mount
the Electro-Voice HP640 horn. The horn
shall have an integral rear mounting bracket
madeof 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 mate-
rials 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 pe-
riod, 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
Warranty does not apply to: (a) exterior fin-
ish or appearance; (b) certain specific items
described in the individual product-line
statement(s)below, or in the individual prod-
uct data sheet or owner’s manual; (c) mal-
function 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 Electro-
Voice Service or any of its authorized service
representatives. Obtaining Warranty Ser-
vice:To obtain warranty service, a customer
must deliver the product, prepaid, to Elec-
tro-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 avail-
able from Electro-Voice Service at 600 Cecil
Street, Buchanan, MI 49107 (800/234-6831
or FAX [phone]). Incidental and
Consequential Damages Excluded: Prod-
uct repair or replacement and return to the
customer are the only remedies provided to
the customer. Electro-Voice shall not be li-
ableforany incidental or consequential dam-
ages including, without limitation, injury to
persons or property or loss of use. Some
states do not allow the exclusion or limita-
tion 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-Voice Speakers and Speaker Sys-
temsare guaranteed against malfunction due
to defects in materials or workmanship for a
periodoffive (5) years from the dateoforigi-
nalpurchase.The Limited Warranty 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 pur-
chase. Additional details are included in the
Uniform Limited Warranty statement.
For warranty repair or service informa-
tion, contact the service repair department
at: 616/695-6831 or 800/685-2606.
Fortechnical assistance, contact Technical
Support at 800/234-6831 or 616/695-6831,
M-F, 8:00 a.m. to 5:00 p.m. Eastern Stan-
dard Time.
Specifications subject to change without
notice.

MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
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MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
Figure 1—Polar Response 5 dB per division
HORIZONTAL
VERTICAL
1.6 kHz
160 Hz
2 kHz
200 Hz
500 Hz
2.5 kHz
250 Hz
3.15 kHz
315 Hz 400 Hz
630 Hz 800 Hz

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MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
10 kHz 16 kHz
4 kHz 5 kHz 6.3 kHz
8 kHz
Figure 2—Typical Axial Frequency
Response (with EQ)
110
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
100
90
FREQUENCY IN HERTZ
RESPONSE IN dB

MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
6
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
Figure 4—Impedance Response, MB
Horn Alone
Figure 5—Distortion Response, 10%
Power, MB Horn Alone
Figure 3—Axial Frequency Response (1
watt/1 meter), MB Horn Alone
110
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
100
90
FREQUENCY IN HERTZ
RESPONSE IN dB
31.6
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
100
316
1
3.16
10
IMPEDANCE IN OHMS
FREQUENCY IN HERTZ
LEVEL IN dB
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
90
100
110
120
60
50
70
80
40
2nd HARMONIC
3rd HARMONIC
FUNDAMENTAL
FREQUENCY IN HERTZ

7
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
Figure 7—Directivity Response
Figure 8—Dimensions
Figure 6—Beamwidth Response
FREQUENCY IN HERTZ
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
80
100
200
300
30
20
40
60
360
BEAMWIDTH IN DEGREES
(-6dB)
HORIZONTAL
VERTICAL
FREQUENCY IN HERTZ
10
0
20
30
DIRECTIVITY INDEX Di (dB)
20 30 50 100 200 500 1,000 2,000 5,000 10,000 20,000
10
1
100
1,000
DIRECTIVITY FACTOR Rθ(Q)
NUMBERS INDICATE
SPECIFIC RθVALUES
4.02
5.43
4.95
6.63
7.34
11.94
16.67
19.56
21.02
21.22
34.95
22.44
25.12
18.33
19.12
19.61
18.53
20.16
37.33
24.63
13.95
20.36

MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
8
MH6040AC Coaxial Constant-Directivity Manifold TechnologyHorn System
HORNS Part Number 535623 — 9927
600 Cecil Street, Buchanan, MI 49107
616/695-6831, 616/695-1304 Fax
©Telex Communications, Inc., 1999 • Litho in U.S.A.
Specifications:
The following specifications are in
accordance with or exceed the AES
Recommended Practice for Specifica-
tions of Loudspeaker Components Used
in Professional Audio and Sound
Reinforcement Systems (AES2-1984;
ANSI S4.26-1984).
Frequency Response, Measured in Far
Field, Calculated to One Watt at One
Meter on Axis, Swept One-Third-
Octave Pink Noise, Anechoic Environ-
ment,
Coaxial Version (see Figure 2):
100 - 20,000 Hz
Non-Coaxial Version (see Figure 3):
100 -4,000 Hz
Low-Frequency 3-dB-Down Point:
150 Hz
Usable Low-Frequency Limit
(10-dB-Down Point):
100 Hz
Average Efficiency:
25%
Long-Term Average Power Handling
Capacity per EIA RS-426A
(see Power Handling section):
600 watts
Maximum Long-Term Mid-Band
Acoustic Output:
150 watts
Sensitivity, 1 Watt (into nominal
impedance) at 1 Meter, Anechoic
Environment, Band-Limited Pink-
Noise Signal:
107 dB
Dispersion Angle Included by 6-dB-
Down Points on Polar Responses,
Indicated One-Third-Octave Bands of
Pink Noise,
200 Hz to 20,000 Hz, Horizontal
(see Figure 6):
60° (+10°, –30°)
315 Hz to 20,000 Hz, Vertical
(see Figure 6):
40° (+20°, –15°)
Directivity Factor Rq(Q), 500 Hz–
20,000 Hz Median (see Figure 7):
24.0
Directivity Index Di(10 log Rq), 500
Hz to 20,000 Hz Median (see Figure
7):
13.8 dB (+0.9, -1.1 dB)
Transducer Complement:
Two DL10X-SH manifold drivers
with Kevlar®epoxy composite cones1
System Impedance, Drivers in Paral-
lel, Nominal/Minimum (mid-bass
section):
8.0/5.9 ohms
Polarity:
A positive voltage applied to the
positive (+) sides of the DL10X-SH
input cables produces a positive
acoustic pressure in the horn throat
Construction,
Main Horn Bell and Driver Back
Covers:
One-piece black polyester and
fiberglass laminate with composite
reinforcement
Hanging Hardware:
Integral black 10-gauge polyester
powder-coated steel
Mechanical Driver Protection:
Integral grille/protection screen
built into the manifold chamber
Coaxial Horn Supplied (mounted in
horn mouth on two steel rails):
HP640
High-Frequency Drivers and Driver-
Manifold Systems for Coaxial HP640
Horn (contractor selected and in-
stalled):
DH1A, DH1A/2MT, DH2A, DH2A/
4MT, N/DYM®1 and N/DYM®1/2MT
Input Connections,
DL10X-SH:
Heavy-duty 12-AWG oxygen-free
copper cable, unterminated, in exte
rior grade UV-stabilized flexible
conduit
High-Frequency Driver(s):
Heavy-duty 12-AWG oxygen-free
copper cable, unterminated, in exte-
rior grade UV-stabilized flexible
conduit
Recommended Crossover,
Frequency:
1,250 Hz
Slope:
24 dB per octave
Recommended High-Frequency
Driver Delay:
2.96 msec ±0.3 ms
Dimensions (see Figure 8),
Height:
149.9 cm (59.0 in.)
Width:
99.1 cm (39.0 in.)
Length:
187.3 cm (73.9 in.)
Packed Length:
203.2 cm (80.0 in.)
Weight:
75 kg (165 lb)2
Shipping Weight:
80 kg (176 lb)
Packing:
Wooden pallet
______________
1. Kevlar®is a registered trademark of Du Pont.
2. Without high-frequency drivers (see Installation section).