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.
1
This
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-
grally mounted to the fiberglass horn bell via
a heavy-duty mounting bracket and propri-
etary Aperiodic Enhancer
TM
phase plug.
Manifolding allows the output of two 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-
matically increased intelligibility, 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
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 sup-
ported. The MH6040AC can be easily sus-
pended with either the 60° or the 40° cover-
age pattern horizontal. Note: the contractor-
selected 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 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
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-resis-
tant boxes if used in adverse conditions. The
mounting brackets incorporate a predrilled
