Electro-Voice Deltamax System DML-1152A User manual

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Eleciro-Voice'
THE DELTAMAX™ SYSTEM
OWNER'S MANUAL
DMC 1152B CONTROLLER
DML-1152A/DML-1152MC LOUDSPEAKERS

THE DELTAMAX™ SYSTEM
DESCRIPTION
GENERAL
The DeltaMax™ DMC-1152B/DML-1 152A and
DMC-1152B/DML-1152MC systems consist of two-
way biamped, high-performance speaker systems
and companion electronic controllers. The DML-
1152A is a full-range loudspeaker system intended
for high-level sound reinforcement in touring-sound
and permanent-installation applications. The trap-
ezoidal cabinet shape allows tight cluster designs,
enabling maximum mutual coupling and single-
point-source arrays. The DML-1152MC is a slant-
monitor version of the DML-1152A. The unique
circuitry of the DMC controller provides accurate
protection for the loudspeakers without the use of
shifting high-pass or low-pass filters, shifting cross-
over frequencies or independent bandpass com-
pression. The electronic protection is invoked only
when catastrophic conditions are present for the
loudspeakers. The result is that accurate fre-
quency response is maintained from the lowest
sound pressure levels to the very highest sound
pressure levels available from the loudspeakers.
There are two models in the ОМІ 11524 series:
the DML-1152AP (painted finish) and the
DML-1152APF (painted finish with flying hardware).
The DML-1152MC model is a carpet-covered slant-
monitor version of the DML-1152A and does not
have a flying hardware option.
The DML-1152A and DML-1152MC employ a
15-inch woofer for low-frequency reproduction, and
a standard 2-inch-exit DH1A compression driver.
The systems use flat-front, constant-directivity,
high-frequency homs which are based on the
Electro-Voice HP series (Patent $4,685,532) and
are geometrically optimized for performance from
1,250 Hz to 20,000 Hz.
The DeltaMax™ flying version model
DML-1152APF includes three steel-reinforced
aircraft-type pan fittings on the top and bottom of
the enclosures to facilitate the hanging of multi-
cabinet arrays. Each DeltaMax™ flying system is
packed with a separate owner's manual which pro-
vides specific hanging instructions.
The electronic circuits are designed to provide
optimum audio performance, even when the audio
drive level is increased for maximum loudness.
Precise speaker modeling circuits control a high-
performance compressor and voltage limiter which
provide speaker excursion protection, voice-coil
temperature protection, and amplifier maximum-
power limiting.
Where very high levels of deep bass are required,
the DMC-2181S/DML-2181A DeltaMax™ subwoof-
er system may be added to the DMC-1152B/
DML-11524 or the DMC-1152B/DML-1152MC
combinations. The DML-2181A loudspeaker cabi-
net, with two manifolded eighteen-inch speakers,
Description
and the DMC-2181 series electronic controllers
were designed specifically to work in conjunction
with the two-way systems to provide extremely
high-level low-frequency output down to 35 Hz.
Optimum performance of these speakers can only
be assured when used with their dedicated elec-
tronics. Do not use with other electronic cross-
overs and/or processors.
NOTE: The performance of the DML-1152MC
slant-monitor system is identical to the
DML-1152A series speaker systems. Henceforth,
throughout this manual all references to the
DML-11524 series will be assumed to include the
DML-1152MC.
FEATURE SUMMARY
Fourth-order Linkwitz-Riley crossover filters
provide smooth, accurate response through the
crossover region.
Special equalization circuits allow flat, wideband
system response.
Sensing circuits for the drivers control the com-
pressor and voltage limiter to prevent voice-coil
overheating, overexcursion and amplifier slipping
without affecting spectral balance or
program dynamics.
Dual-time constant compressor circuit with
variable compression ratio reduces peak
and average levels for loudspeaker thermal
protection and amplifier clipping prevention as
necessary while preserving relative program
dynamics.
* Voltage-clamp loudspeaker excursion protection
does not alter overall program dynamics or fre-
quency response.
A connection to the control voltage is available
through a jack on the back panel. This allows
precise gain tracking when more than one unit is
used.
The front panel display shows drive signal level
and compressor gain reduction. Sensing display
for each sense channel shows amplifier limit, ex-
cursion limit, and temperature limit. When its
limit is approached, each LED lights yellow.
Speaker system is trapezoidal for compact ar-
rays. Flying versions feature integral, steel-rein-
forced fittings to facilitate hanging.
Both the woofer and the compression driver em-
ploy the best available technology for high power
and accurate sound reproduction.
A state-of-the-art, flat-front, constant-directivity
horn is utilized for even coverage and flat re-
sponse.
page 1

THE DELTAMAX™ SYSTEM
Specifications
CONTROLLER SPECIFICATIONS
CHANNEL CONFIGURATIONS:
Monoaural two-way; two sense channels
FILTER TYPE:
4th-order Linkwitz-Riley
CROSSOVER FREQUENCY:
1,100 Hz
GAIN:
5 dB nominal
SIGNAL PATH EQUALIZATION (see Figure 1),
LF EQ:
-3 dB at 33 Hz, +10 dB at 55 Hz
LF Signal Delay:
0.49 ms at crossover frequency
HF EQ:
4th order optimized for DML-1152A series
HF driver and horn
TOTAL HARMONIC DISTORTION, 20 - 20,000 Hz:
0.03% typical, 0.1% maximum
NOISE, EACH OUTPUT, 20 - 20,000 Hz NBW,
TYPICAL:
-86 dBu
Electronically balanced differential
Maximum Level:
+18 dBu
Impedance:
27,000 ohms and .0015mf
CMRR, Typical:
—55 dB
Connector:
Female 3-pin XLR-type
SENSE CHANNEL INPUTS,
Type:
Floating differential
Maximum Level,
LF: 145 V rms
HF: 145 V rms
Impedance:
100 kilohms each side to ground
Connector:
Two five-way binding posts
OUTPUTS (LF and HF):
Type:
Transformer floating differential
Maximum Level:
+18 dBu
Minimum Load Impedance for Full Level:
600 ohms
Connectors:
Male 3-pin XLR-type
POWER REQUIREMENTS:
100, 120, 220, 240 V ac, 50 - 60 Hz, 13 W
CHASSIS CONSTRUCTION:
Painted steel
COLORS:
Gray front panel/black chassis with white graphics
MOUNTING:
EIA 19-inch rack mount, 1.75 in. high, 8.97 in.
behind panel (including connectors); supplied
with front-panel security cover for controls.
SYSTEM SPECIFICATIONS
Frequency Response, Measured in Farfield,
Calculated to One Meter on Axis, Swept One-Third-
Octave Pink Noise, One Watt into LF Midband
(2.83 V at 250 Hz), Anechoic Environment, +3 dB
(see Figure 2):
50-20,000 Hz
Sound Pressure Level at One Meter, One Watt
Input Power, Anechoic Environment, Band-Limited
Pink-Noise Signal,
High Frequency:
112 dB
Low Frequency:
100 dB
Typical System Maximum Continuous Sound
Pressure Levels at One Meter, Anechoic
Environment:
126 dB
Typical System Maximum Peak Sound Pressure
Levels at One Meter, Anechoic Environment:
132 dB
Crossover Frequency:
1,100 Hz
Beamwidth Angle Included by 6-dB-Down Points
on Polar Responses, Indicated One-Third-Octave
Bands of Pink Noise (see Figure 4),
1.2-20 kHz Horizontal:
60° (+25°, -5°)
1.2-20 kHz Vertical:
40° (+25°, -5°)
Directivity Factor R, (Q) 1.0-20 kHz Median
(see Figure 5):
19.3 (412.8, —7.3)
Directivity Index D, 1.0-20 kHz Median
(see Figure 5):
12.1 dB (+3.0 dB, -1.3 dB)
Distortion, 120 dB SPL at 1 Meter,
Shaped Spectrum (see Figure 6),
Second Harmonic
100 Hz:
4.396
800 Hz:
1.096
Third Harmonic
100 Hz:
0.7%
800 Hz:
1.4%
2,000 Hz:
0.796
5,000 Hz:
1.796

THE DELTAMAX™ SYSTEM Specifications
з SPEAKER SPECIFICATIONS
Transducer Complement,
High Frequency:
DH1A compression driver (2-inch exit)
Low Frequency:
DL15X 15-inch woofer
Efficiency,
High Frequency:
2596
Low Frequency:
5.0%
Long-Term Average Power Handling Capacity,
High Frequency (per AES2-1984):
75 watts
Low Frequency (per ЕА RS-426A):
400 watts
Short-Term Power Handling Capacity,
High Frequency:
300 watts
Low Frequency:
1,600 watts
Maximum Long-Term Midband Acoustic Output,
High Frequency:
18.8 watts
Low Frequency:
20.0 watts
Nominal Impedance,
High Frequency:
8 ohms
Low Frequency:
8 ohms
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FIGURE 1 - DMC-1152B Frequency Response
Minimum Impedance,
High Frequency:
6.5 ohms
Low Frequency:
7.9 ohms
Dimensions,
Height:
75.9 cm (29.88 in.)
Width:
45.2 cm (17.78 in.)
Depth:
41.4 cm (16.28 in.)
Net Weight:
43.3 kg (96 Ib)
Shipping Weight:
47.4 kg (105 Ib)
Enclosure Materials,
Structural:
3/s-inch 14-ply birch plywood
Finish:
Black textured paint
Grille:
Steel with charcoal-gray foam
Hanging (DML-1152APF only):
3-point flying system (accepts Aeroquip 32326 and
32343 fittings)
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FREQUENCY IN HERTZ
FIGURE 2 - DMC-1152B/DML-1152A
Axial Frequency Response
(1 watt/1 meter into LF midband)
page 3

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THE DELTAMAX™ SYSTEM Fi
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FIGURE 4 - DMC-1152B/DML-1152A FIGURE 5 - DMC-1152B/DML-1152A
Beamwidth vs. Frequency Whole Space Directivity Factor and Directivity Index
(anechoic) vs. Frequency Whole Space (anechoic)
(Shaped to reflect typical
music frequency spectrum)
LEVEL IN dB
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FIGURE 6 - DMC-1152B/DML-1152A
Harmonic Distortion
(120 dB SPL/1 meter using typical
music frequency spectrum)
DIRECTIVITY INDEX Di (dB)
page 6

THE DELTAMAX™ SYSTEM
Operation
PICTORIAL 1 — DMC-1152B Front Panel Diagram
OPERATION
FRONT PANEL INDICATORS AND CONTROLS
(refer to pictorial 1)
1. INPUT LEVEL INDICATORS: Three LEDs
show the drive level at the input of the control-
ler. Levels are calibrated in dBu (-20, 0, + 16)
NOTE: Do not allow the 16-dB input-level
indicator to stay on continuously. If the 16-dB
indicator is allowed to stay on for long periods,
the input circuit will clip. The input signal
should be reduced until the 16-dB indicator
lights only on loud instantaneous peaks.
GAIN REDUCTION INDICATORS: Three
LEDs show how much gain reduction is occur-
ring in the compressor at the input of the con-
troller. The display is calibrated in relative dB
(3, 6, 12). Gain reduction occurs only when the
maximum temperature, excursion and amplifier
capabilities are exceeded for either the woofer
or compression driver. The Output-Limits dis-
play indicates which limits are being exceeded
when gain reduction occurs.
NOTE: Do not allow the 12-dB-gain-reduction
indicator to stay on continuously. If the 12-dB
indicator is allowed to stay on for long periods,
the speaker may be damaged. The input
signal should be reduced until the 12-dB
indicator lights only on loud passages.
3. OUTPUT LIMIT INDICATORS:
A. TEMPERATURE LIMIT: These LED's
light when the temperatures of the woofer
or compression-driver voice coils
approach their maximum allowable limit.
Under this condition, gain reduction will
occur at the input of the controller so that
the maximum-temperature limits will not
be exceeded for either the woofer or
compression driver.
B. EXCURSION LIMIT: These LED's light
when the excursion of the woofer cone or
compression-driver diaphragm approach
their maximum allowable limit. Under this
condition, voltage clamping will occur at
the output of either the low- or high-
frequency section so that the maximum-
excursion limits will not be exceeded for
either the woofer or compression driver.
C. AMPLIFIER LIMIT: These LED's will
provide status information for the high-
and low-frequency power amplifiers if the
controller has been calibrated to the
amplifiers. (See the AMPLIFIER/
CONTROLLER CALIBRATION section.)
With the Cal/Clip-Limit switch pressed in,
the LED's will signal the occurence of
amplifier clipping. With the switch in the
outward position, the LED's indicate that
gain reduction in the form of hard limiting
is occurring at the input of the controller to
prevent the amplifiers from clipping.
OUTPUT LEVEL CONTROLS:
A. LF: This control adjusts the level of the
low-frequency output signal. The control
range is from -12 dB to +12 dB.
NOTE: The gain has been structured within
the DMC-1152B controller so that DML-1152A
loudspeaker will have a flat frequency re-
sponse (as shown in Figure 3) in an anechoic
environment with the output levels of the
controllers set in the 0-dB-detent position and
with the amplifier channels having identical
gain driving the LF and HF sections of the
speakers.
page 8

THE DELTAMAX™ SYSTEM Operation
OPERATION (continued)
5. AMPLIFIER CALIBRATION CONTROLS:
These controls are used for calibrating the con-
troller to both the low- and high-frequency am-
plifiers so that the controller can monitor the
clipping of the amplifier outputs and, if desired,
act as a limiter to prevent amplifier clipping.
See AMPLIFIER/CONTROLLER CALIBRA-
TION section.
NOTE: The calibrated markings on the front
panel correspond to the power level that an
amplifier would deliver to an 8-ohm load. A
crude, approximate calibration can be ob-
tained by rotating the control until the slot of
the trimpot points at a power level equivalent
to the amplifier power rating for an 8-ohm
load. (When the trimpot is in its mid position it
is pointing at 400 watts.)
6. CAL-CLIP LIMIT SWITCH: This switch selects
the mode that controller will monitor the amplifi-
ers (assuming that the controller has been cali-
brated to the amplifiers - see AMPLIFIER/
CONTROLLER CALIBRATION section). With
the switch pushed in, the Amplifier Limit LED's
will indicate when the amplifiers are clipping.
With the switch in the outward position, the Am-
plifier Limit LED's will indicate that gain reduc-
tion is occurring to prevent the amplifiers from
clipping.
NOTE: If the controller has not been cali-
brated to both the low- and high-frequency
amplifiers, the Cal/Clip Limit switch should be
pushed in. This will defeat the compressor/
limiter from trying to prevent amplifier clipping.
(The Amplifier Limit LED's will still flash when
the amplifier exceeds the power levels that the
Amplifier Calibration trimpots are set to.) Poor
sound quality can result with incorrect calibra-
tion and the compressor/limiter engaged.
7. POWERINDICATOR: This LED lights when
the controller is on.
8. POWER SWITCH: This switch turns the con-
troller on and off.
BACK PANEL CONNECTIONS (refer to Pictorial 2)
1. AC POWER CORD RECEPTACLE: This re-
ceptacle is for the ac power cord (supplied with
the unit).
2. FUSE RECEPTACLE: This fuse receptacle
requires either a 0.25 A 250 V slow blow fuse
(for 100/120 V ac operation), or a 0.1 A 250 V
slow blow fuse (for 220/240 V ac operation).
3. SENSE INPUTS:
A. LF: This input is for the connection of the
sense line to monitor the power delivered
to the woofer and should be connected to
the output of the low-frequency amplifier.
B. HF: This input is for the connection of the
sense line to monitor the power delivered
to the compression driver and should be
connected to the output of the high-
frequency amplifier.
NOTE: The Sense Inputs are floating differen-
tial with 5-way binding posts, see CONNEC-
TOR and CABLE REQUIREMENTS section
for detailed wiring information.
4. OUTPUTS:
A. LF: This input is the low-frequency output
of the DMC crossover/controller and
should be connected to the input of the
low-frequency amplifier.
B. HF: This connection is the high-frequency
output of the DMC crossover/controller
and should be connected to the input of
the high-frequency amplifier.
PICTORIAL 2 — DMC-1152B Back Panel Diagram

THE
DELTAMAX™
SYSTEM
Operation
OPERATION (continued)
5. GAIN CONTROL BUS: This '/4-inch jack is for
slaving the gain-control busses of other DMC
controllers to enable gain tracking in a multiple-
controller system. See CONNECTOR and
CABLE REQUIREMENTS section for detailed
wiring information.
6. INPUT: This connection is for the full-range
signal input to the DMC controller. This input is
electronically balanced with a female 3-pin
XLR-type connector with pin 1 as a ground ref-
erence, ріп 2 high (+) and pin З low (-). See
CONNECTOR and CABLE REQUIREMENTS
section for detailed wiring information.
TYPICAL SYSTEM OPERATION
The
DML-1152A
is
a
full-range
biamped
loudspeak-
er
system
to
be
used
with
the
DMC-1152B
elec-
tronic
controller.
The
DML-1152MC
is
a
slant-monitor
version
of
the
DML-1152A
and
is
also
used
with
the
DMC-1152B
controller.
Besides
con-
ventional
frequency
division,
the
DMC
electronic
controllers
have
equalization
and
time
delay
to
ob-
tain
optimum
performance
from
their
respective
DeltaMax™
DML
loudspeaker
systems.
In
addition,
sense
lines
to
the
controllers
monitor
the
voltage
drive
to
each
loudspeaker
in the
system
and
auto-
matically
activate
protection
circuitry
to
prevent
cone/diaphragm
overexcursion,
voice-coil
overheat-
ing
and
amplifier
clipping.
Before
operating
a
DeltaMax™
system,
the
user
should
read
this
man-
ual
thoroughly
and
make
sure
that
the
system
has
been
set
up
as
detailed
in
the
INSTALLATION
sec-
tion
and
the
amplifiers
and
controller
have
been
calibrated
as
detailed
in
the
AMPLIFIER/CON-
TROLLER
CALIBRATION
section.
The
gain
and
equalization
structures
in
the
DMC
controllers
have
been
set
up
so
that
the
DML
loud-
speaker
systems
will
have
a
flat
frequency
re-
sponse
(in
an
anechoic
environment)
when
the
Output
Level
trimpots
on
the
controllers
are
set
in
the
0-dB
detent
position
and
the
amplifiers
all
have
the
вате
gain
(i.e.,
the
amplifiers
are
calibrated
for
32
dB
of
gain
as
detailed
in
the
AMPLIFIER/CON-
TROLLER
CALIBRATION
section).
This
gives
the
user
a
standard
reference
every
time
the
system
is
setup.
Adjustments
to
the
drive
levels
of
the
low-
and
high-frequency
sections
are
then
only
needed
to
compensate
for
room
acoustics
or
array
configu-
rations.
When
adjustments
are
required,
they
should
be
made
with
the
Output
Level
trimpots
on
the
controllers.
The
level
controls
on
the
amplifiers
should
be
left
in
their
calibrated
positions.
(See
the
MULTIPLE
LOUDSPEAKER
ARRAY
section
for
circumstances
when
it
is
permissible
to
adjust
the
amplifier
level
controls.)
The
input
circuit
of
the
DMC
controllers
clips
with
a
*18
dBu
(6.2
volts
rms)
input
signal.
The
input-
signal
level
display
has
three
LED's
calibrated
to
-20,
0
and
+16
dBu.
To
avoid
clipping,
the
input
should
be
driven
only
to
the
point
that
the
+16
dB
LED
lights
on
instantaneous
peaks.
If
more
gain
is
desired
from
the
controller,
the
Output
Level
trimpots
may
be
turned
up.
Note
that
there
are
cali-
brated
markings
on
the
front
panel
of
the
controller
(3
dB
per
division)
to
enable
accurate
gain
adjust-
ments.
Extensive
modeling
circuits
allow
the
controller
to
monitor
the
status
of
the
voice-coil
temperature
and
the
cone/diaphragm
excursion
of
the
loudspeakers
in
each
frequency
band.
If
a
loudspeaker
in
one
of
the
frequency
bands
approaches
its
maximum
ther-
mal
limit,
a
multi-time-constant
compressor
circuit
with
a
variable
compression
ratio
will
reduce
the
peak
and
average
levels
of
the
full-range
input
sig-
nal
as
necessary
to
protect
the
driver,
while
pre-
serving
the
spectral
balance
and
the
relative
program
dynamics.
When
gain
reduction
occurs,
an
Output
Limit
Temperature
LED
will
light
indicat-
ing
which
frequency-band
loudspeaker
is
reaching
its
thermal
limit.
If
a
loudspeaker
in
one
of
the
fre-
quency
bands
approaches
its
maximum
excursion
limit,
a
dynamic
frequency-sensitive
voltage-clamp-
ing
circuit
at
the
output
of
that
frequency
band
will
clamp
the
peak
of
the
output
waveform
at
a
level
above
which
excursion
damage
would
occur
to
the
loudspeaker;
hence,
preserving
the
overall
spectral
balance.
When
voltage
clamping
occurs,
an
Output
Limit
Excursion
LED
will
light
indicating
which
fre-
quency-band
loudspeaker
is
reaching
its
excursion
limit.
The
DMC
Controller
will
also
prevent
long-term
amplifier
clipping.
The
controller
must
be
calibrated
as
detailed
in
the
AMPLIFIER/CONTROLLER
CALIBRATION
section
and
the
Cal/Clip
Limit
switch
must
be
in
the
Out
position
for
this
function
to
work
properly.
If
an
amplifier
in
one
of
the
fre-
quency
bands
approaches
clipping,
a
multi-time-
constant
compressor-limiter
circuit
will
reduce
the
peak
and
average
levels
of
the
full-range
input
sig-
nal
as
necessary
to
prevent
long-term
clipping
while
preserving
the
overall
spectral
balance.
When
gain
reduction
occurs,
an
Output
Limit
Ampli-
fier
LED
will
light
indicating
which
frequency-band
amplifier
is
reaching
its
power
limit,
With
the
Cal/
Clip
Limit
switch
pushed
in,
gain
reduction
will
not
occur
to
prevent
amplifier
clipping
and
the
Output
Limit
Amplifier
LED's
will
simply
indicate
when
the
amplifiers
are
going
into
clipping.
The
DeltaMax™
DMC
controllers
provide
protection
for
the
loudspeakers
without
affecting
the
overall
spectral
balance
or
dynamic
range.
The
controllers
have
an
LED
display
to
inform
the
user
when
the
protection
circuitry
is
activated
and
what
is
causing
the
protection
to
take
place.
Each
frequency
band
—
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em——————————————————————————dMdMEÁÉÁEM
—
page 10

THE DELTAMAX™ SYSTEM
OPERATION (continued)
has three LED's to indicate loudspeaker thermal-
protection activation, loudspeaker excursion protec-
tion activation and amplifier clipping (or amplifier
clipping prevention). In addition, there is an LED
display to indicate the amount of long-term overall
gain reduction occurring due to loudspeaker ther-
mal protection and amplifier clipping prevention.
(The instantaneous loudspeaker excursion voltage-
clamping protection is not reflected in the overall
gain-reduction display.)
In very high-powered applications, the detailed dis-
plays on the DMC controllers provide the user with
information to make adjustments or changes to the
system (if desired) to eliminate the protection and
increase the acoustic output. For example:
e If an excessive amount of low-frequency protec-
tion is occurring, selective equalization can be
used ('/s-octave-band equalizer, parametric
equalizer, etc.) to reduce the level in the fre-
quency range that is causing the excessive ex-
cursion, allowing the overall level to be turned
up. If the desired amount of high-level low-
frequency response still cannot be obtained,
subwoofers (or additional subwoofers) should be
added to the system.
e If an excessive amount of loudspeaker thermal
protection is occurring in any frequency band,
more speaker systems are generally needed. If
the program material has a lot of energy concen-
trated in a relatively small frequency range, se-
lective equalization may serve as an effective
compromise.
Operation
e If excessive amplifier clipping (or amplifier clip-
ping prevention) is occurring without excessive
loudspeaker thermal protection or excursion pro-
tection, larger power amplifiers should be used.
* |f excessive loudspeaker thermal protection and
excursion protection is occurring, more speakers
should be used.
* |fexcessive overall gain reduction is occurring,
more speakers should be added.
e Ifthe 12-dB-gain-reduction LED is on for any sig-
nificant portion of time, the level should be
turned down. Levels driven beyond this point
may exceed the protection capability of the pro-
tection circuitry.
When multiple controllers are used (such as in a
stereo system) the control voltages should be
slaved together as detailed in the INSTALLATION
section. The gain of all of the controllers will then
track whenever gain reduction occurs due to loud-
speaker thermal protection or amplifier clipping pre-
vention, regardless of which loudspeaker or
amplifier was exceeding its limit. This will prevent
acoustic image shifting at very high levels. When a
DMC-2181S/DML-2181A subwoofer system is
used with a full-range DeltaMax™ system (such as
a DMC-1152B/DML-1152A) the control voltages
should be slaved together to prevent spectral bal-
ance shifting at high levels when gain reduction oc-
curs for loudspeaker thermal protection or amplifier
clipping prevention. The loudspeaker excursion
voltage-clamping protection will still operate inde-
pendently in each frequency band in each controller
when the control voltages are slaved.
page 11

THE DELTAMAX™ SYSTEM
AMPLIFIER/CONTROLLER CALIBRATION
AMPLIFIER CALIBRATION PROCEDURE
Maximum performance of the DeltaMax™ controller
protection circuitry occurs, under the most severely
over-driven conditions, when the voltage gain of the
amplifiers fall in the range of 27 to 35 dB (with 32
dB being optimum). This gain range is typical of
most high-power amplifiers and can easily be ad-
justed by simply adjusting the level controls on the
amplitier.
The procedure for calibrating an amplifier to have
32 dB of gain is as follows:
1. With the amplifier turned on and without speak-
ers hooked on the amplifier output, apply 0.5-
volt rms 1,000-Hz sinewave signal to the input
of the amplifier.
2. Adjust the amplifier level control until the output
of the amplifier measures 20 volts rms.
NOTE: If the amplifier will be operated in the
mono-bridged mode, it should be calibrated
when wired in the mono-bridged configuration.
CONTROLLER CALIBRATION PROCEDURE
This procedure is for calibration of the DMC
controller's internal amplifier limit circuits to the ac-
tual clip level of the power amplifiers. Calibration is
set by the LF and HF Amplifier Calibration trimpots
on the front panel.
Before plugging in the ac power cord, be sure the
controller is wired for the correct primary (mains)
voltage.
Disconnect the speakers and remove the security
cover from the controller by removing the two
screws on the front panel of the controller. Perform
the following procedure:
1. Connect the controller to the low- and high-fre-
quency power amplifier channels as detailed in
the INSTALLATION section.
2. Besure the controller LF and HF Sense Inputs
are connected to the correct amplifier outputs
and the speakers are disconnected from the
amplifier.
3. Setthe low- and high-frequency amplifier gain
controls for 32 dB voltage gain, or as close as
possible to 32 dB (this is optimum, but it can be
in the range of 27 to 35 dB). See the AMPLI-
FIER CALIBRATION PROCEDURE section.
4. Tum the LF and HF Amplifier Calibration
trimpots on the controller to full counterclock-
wise. Press the Cal/Clip Limit switch to its re-
cessed Cal/Clip position with a screwdriver or
other suitable tool.
5. In order to prevent thermal! limiting from occur-
ring while calibrating the amplifier limit levels,
insert a shorted ‘/4-inch phone plug (tip-sleeve)
10.
13;
Amplifier/Controller Calibration
into the Gain control bus jack on the back of
the controller. The Thermal Limit LED may still
come on but no gain reduction should be indi-
cated.
Send a 500-Hz sinewave test signal to the con-
troller input.
Adjust the signal source level until the low-
frequency amplifier begins to clip (you may
turn up the LF Output Level on the controller if
necessary to get the amplifier to clip). Clipping
is noted by the clip indicator on the power
amplifier or by monitoring the output with an
oscilloscope. Now, turn the level down until the
clip light just goes out (or until the clipping dis-
appears on the oscilloscope).
Turn the LF Amplifier Calibration trimpot on the
controller clockwise with a screwdriver until the
LF Amplifier Output Limit LED comes on. Note
that the slot of the trimpot is pointed at the
approximate power rating of the amplifier for an
8-ohm load as denoted by the calibrated mark-
ings on the front panel of the controller. Note
also that this is the maximum amount of power
capable of being delivered to a single driver in
this amplifier configuration.
The LF section of the controller is now calibrat-
ed. The LF Output Level trimpot may be adjust-
ed as necessary for the desired frequency
spectrum balance without affecting calibration.
Change the input test signal to a frequency of
5,000 Hz.
Adjust the signal source level until the high-fre-
quency amplifier begins to clip (you may turn
up the HF Output Level on the controller if nec-
essary to get the amplifier to clip). Now, turn
the level down until the clip light just goes out
(or until the clipping disappears on the oscillo-
Scope).
Turn the HF Amplifier Calibration trimpot on the
controller clockwise with a screwdriver until the
HF Amplifier Output Limit LED comes on. Note
that the slot of the trimpot is pointed at the ap-
proximate power rating of the amplifier for an 8-
ohm load as denoted by the calibrated
markings on the front panel of the controller.
Note also that this is the maximum amount of
power capable of being delivered to a single
driver in this amplifier configuration. If the
power rating of the high-frequency power am-
plifier is much greater than 250 watts (and,
hence, the HF Amplifier Calibration trimpot on
the controller is set much greater than 250
watts), then an additional margin of safety for
the high-frequency driver can be obtained by
setting the HF Amplifier Calibration trimpot to
250 watts.
page 12

THE DELTAMAX™ SYSTEM Amplifier/Controller Calibration/installation
AMPLIFIER CALIBRATION PROCEDURE
(continued)
The HF section of the controller is now calibrat-
ed. The HF Output Level trimpot may be ad-
justed as necessary for the desired frequency
spectrum balance without affecting calibration.
12. Remove the shorted '/4-inch phone plug
from the Gain Control Bus jack and set the
Cal/Clip Limit switch to the Limit position (out).
Set the HF and LF Output Level controls to
their center-detent position (or as desired).
13. Turn the amplifier off and connect the speaker
cables to the output of the amplifier. Make cer-
tain that the “lows” are wired to the woofer and
that the "highs" are wired to the compression
driver. In addition, be sure to observe polarity
when making speaker connections.
NOTES:
A. The Amplifier Calibration trimpots may be
adjusted during use with program material
to set the desired amount of amplifier
limiting. The limiter in the controller will
allow some fast transient peaks through,
allowing some amplifier clipping to occur
on signal peaks after the calibration
procedure. The limiter circuit will,
however, prevent long-term amplifier
clipping when adjusted properly.
B. The Cal/Clip Limit switch may be left in the
recessed Cal/Clip position (in) if the power
amplifier has an internal limiter, or if clip
protection is not desired., When left in the
Cal/Clip position, the Amplifier Output
Limiter indicators on the front panel of the
controller will indicate when the amplifier
is self-limiting or clipping.
C. Iftwo or more speakers are connected in
parallel to an amplifier output, most
amplifiers will exhibit a drop in clipping
voltage due to the lower load impedance.
This will require that the Amplifier
Calibration trimpot be set to a value
slightly lower than the value obtained in
the "no-load" calibration test.
Note that the result of this is that, even
when multiple speakers are paralleled on
an amplifier channel, the Amplifier
Calibration trimpot will always end up
pointing at the maximum amount of power
(on the calibrated markings on the front
panel) that the amplifier is capable of
delivering to each individual driver no
matter how many drivers are connected in
parallel.
D. Do not change the amplifier gain, or
recalibration will be necessary. Use the
LF and HF Output Level controls on the
controller to change power amplifier drive
levels. The Output Level controls do not
affect controller calibration
INSTALLATION
AMPLIFIER REQUIREMENTS
Professional power amplifiers with the following
ratings are recommended for use with the
DMC-1152B/DML-1152A system:
LF: 400-800 watts continuous into eight ohms
HF: 125-250 watts continuous into eight ohms
The use of amplifiers with lower power ratings is
acceptable, however, the full-power capabilities of
the system will not be realized. The use of amplifi-
ers with significantly higher power ratings is waste-
ful and may endanger the loudspeakers; it is
generally not recommended.
Under certain circumstances, however, higher rated
power amplifiers are acceptable. It is acceptable to
drive the DML-1152A speaker with a stereo power
amplifier having the recommended LF power rating,
utilizing one channe! to drive the low frequencies
and the other channel to drive the high frequencies.
For an extra degree of protection when operating in
this configuration, the user may want to set the HF
Amplifier Calibration level to the 250-watt position
to limit excessively high power levels from reaching
the compression driver.
DML-1152A speakers may be paralleled with other
DML-1152A speakers if the amplifier is capable of
delivering adequate power to each speaker at the
lower impedance. Under no circumstances should
DML-1122A and DML-1152A speakers be paral-
leled on the same amplifier channels.
NOTE: For proper operation of the protection
circuitry, the power amplifiers must be
calibrated to have a voltage gain between
27 and 35 dB (32 dB is optimum). See the
AMPLIFIER/CONTROLLER CALIBRATION
section.
CONNECTOR AND CABLE REQUIREMENTS
Controller Connections
The DeltaMax™ controllers have 3-pin XLR-type
connectors for signal input and output. The input is
electronically balanced and has a female connector
with pin 1 as a referenced ground, pin 2 high (+)
and pin 3 low (-). The outputs are transformer bal-
anced and have male connectors with pin assign-
ments identical to the input. Figure 13 illustrates
the preferred interconnection between the controller
and the power amplifier. When driving unbalanced
lines, pin 3 should be shorted to ground.
page 13

THE DELTAMAX™ SYSTEM
INSTALLATION (continued)
To hook up the DeltaMax™ controller to the power
amplifiers, connect the LF Output of the controller
to the input of the low-frequency amplifier and the
HF Output of the controller to the input of the high-
frequency amplifier. The outputs of the low- and
high-frequency amplifiers are then connected to the
LF input (woofer) and HF input (compression driver)
respectively, of the DML-1152A speaker system.
See the LOUDSPEAKER CONNECTIONS section
for details of the loudspeaker wiring. See Figures 8
and 9 for two typical system configurations.
Sense lines must be connected to the DeltaMax™
controller so that the power levels being delivered
to the woofer and compression driver can be moni-
tored. This is accomplished by connecting the out-
put of the low-frequency amplifier to the LF Sense
Input on the controller and the output of the high-
frequency amplifier to the HF Sense Input on the
controller. The sense input connectors are 5-way
binding posts wired in a floating differential configu-
ration. This configuration makes it possible to con-
nect sense lines to a bridged amplifier without
shorting out one of the legs of the amplifier. High-
quality banana plugs may be used for these con-
nections, but wires underneath the binding posts
provide greater security. Small gauge wire (e.g. 22
gauge) is acceptable for these connections be-
cause there is minute current flow, but be sure the
connections are secure and safe enough for the
high voltages from the amplifier output.
The gain control bus in the DMC controllers is ac-
cessible through a two-conductor 1/s-inch jack on
the back of the controller. This feature is used when
itis desired for the gain of two or more units to
track. Using a standard '/4-inch patch cable, con-
nect the jacks together. For more than two units,
use Y-connectors. For example:
1. When multiple controllers and loudspeakers
are used (such as in a stereo system), the
controller's Gain Control jacks should be con-
nected together to maintain level balancing and
imaging.
2. When the DMC-1152B/DML-1152A full-range
system is used with the DMC-2181S/
DML-2181A subwoofer system, the controller's
Gain Control jacks should be connected togeth-
er between the two controllers to ensure flat-
frequency response when the controllers are
operating in the protection mode.
Loudspeaker Connections
The DML-1152A speaker system is equipped with
4-pin Neutrik Speakon™ NLAMPR connectors for
electrical connection to the woofer and compres-
sion drivers. Each cabinet has two identical con-
nectors with parallel wiring for connecting additional
DML speaker systems. One mating Neutrik
Installation
Speakon™ NL4FC cable-end connector is supplied
with each system.
Cables, connectors and wiring accessories are
available for the DML speaker systems from Pro
Co. Sound, Inc. and Whirlwind Music Distributors,
Inc. To find your local Pro Co., Whirlwind or
Neutrik dealer, contact:
Pro Co Sound, Inc.
135 E. Kalamazoo Ave.
Kalamazoo, MI 49007
Whirlwind Music Distributors, Inc.
P.O. Box 1075
Rochester, NY 14603
Neutrik USA, Inc.
195-S3 Lehigh Ave.
Lakewood, NJ 08701
The pin connections are as follows:
Pin 1 -= LF (-)
Pin 1 4 = LF (+)
Pin 2- = HF (=)
Pin 2 += HF (+)
Both the low-frequency and high-frequency inputs
present a nominal eight-ohm load to the amplifier;
however, the compression driver has a low-fre-
quency protection capacitor in series.
Multiple Loudspeaker Arrays
Arrays consisting of multiples of identical
DeltaMax™ loudspeaker systems can be imple-
mented in a variety of ways. There does not need
to be one controller for every speaker cabinet.
Generally, there only needs to be as many control-
lers as there are different program sources. For
example; a monaural! program source requires one
DMC-1152B controller; a stereo program source
requires two DMC-1152B controllers; etc. In addi-
tion, а DMC-2181S/DML-2181A subwoofer system
may be added to a DMC-1152B/DML-1152A sys-
tem. The DMC-21818 is a stereo controller with left
and right high outputs (above 100 Hz) and a mono-
summed sub output (below 100 Hz). A monaural
program source requires one ОМС-21815 control-
ler and one DMC-1152B controller; a stereo pro-
gram source requires one DMC-2181S controller
and two DMC-1152B controllers.
For the sake of simplicity, the following discussion
will be confined to the various possible connection
schemes for arrays of identical loudspeakers with
only one program source and without subwoofers.
(A stereo array can be broken down and analyzed
as two separate arrays, each having a separate
program source. Subwoofer wiring is addressed in
the DMC-2181S Owner's Manual.) Amplifier in-
puts, outputs and sense lines will be addressed in
the discussion.
The outputs (SUB OUT, LF OUT, HF OUT, etc.) of
the DMC controllers are connected to the inputs of
page 14

THE DELTAMAX™ SYSTEM
INSTALLATION (continued)
multiple amplifier channels through the use of Y-
cords (or multiple Y-cords). The number of amplifier
channels that can be driven by a single output of a
controller is limited only by the total combined input
impedance of the paralleled amplifiers. The
DeltaMax™ controller outputs can drive a combined
impedance of 600 ohms or greater. (For example,
sixteen amplifiers, each having an input impedance
of 10 k ohms, can be paralleled off of one DMC out-
put.) If itis necessary to parallel additional amplifi-
ers, line-level distribution amplifiers will have to be
employed to drive the amplifier inputs. (Alternative-
ly, multiple DMC controllers with paralleled inputs
could be used to distribute the amplifier load.)
For the case where all of the DeltaMax™ loud-
speakers are paralleled on the output of a single
amplifier channel and only one controller is used,
the sense line to that controller is connected to the
output of the amplifier. In this case, all of the loud-
speakers are driven at the same level and the con-
troller monitors the voltage drive to each speaker.
Make sure that the amplifier is calibrated for 32 dB
of gain and that the controller is calibrated to the
amplifier (see AMPLIFIER/CONTROLLER CALI-
BRATION section).
For the case where the Delta Max™ loudspeakers
are powered by multiple amplifiers, all driven at the
same leve! and only one controller is used, the
sense line to that controller is connected to any one
of the amplifier outputs. Note that this requires the
use of identical amplifiers, each calibrated for 32 dB
of gain and that the controller is calibrated to the
amplifiers (see AMPLIFIER/CONTROLLER CALI-
BRATION section). Although the controller is only
actually sensing one amplifier and one set of loud-
speakers, they all are being protected equally as
long as all of the amplifiers are performing identi-
cally.
For the case where the DeltaMax™ loudspeakers
are powered by multiple amplifiers, each driven at
different levels and only one controller is used, the
sense line to that controller is connected to the out-
put of the amplifier that is delivering the highest
power levels to the loudspeakers. This is a fairly
common occurrence; where the levels of individual
loudspeakers in an array are adjusted to provide
even room coverage. In this case, the amplifier be-
ing sensed must be calibrated for 32 dB of gain and
the controller is calibrated to that amplifier. (See
AMPLIFIER/CONTROLLER CALIBRATION sec-
tion.) The other amplifiers must be identical to the
one being sensed, with the exception that their lev-
els are turned down as necessary to obtain even
room coverage. Although the controller is actually
sensing only one amplifier and one set of loud-
speakers, they are all being protected because the
one being driven the hardest is triggering the pro-
tection.
Installation
Note in the last two examples where multiple ampli-
fiers are used to power multiple loudspeakers in an
array, the level setting and calibration of the amplifi-
ers are critical to ensure that all of the loudspeakérs
are protected with only one sense line. If in the nor-
mal course of operation the level settings of the
amplifiers are likely to be tampered with, the sys-
tem should be set up with one controller per ampli-
fier, allowing each set of speakers to be monitored.
In this case, each amplifier would be calibrated for
32 dB of gain and any level adjustment of loud-
speakers would be done with the Output Level
trimpots on the controllers.
It should be noted that, when multiple DML-1152A
loudspeaker systems are closely assembled in an
array, a build up of low and lower-mid frequencies
can occur. The cause of this phenomenon is two-
fold. Mutual acoustic coupling between woofers at
the lowest frequencies (typically below 100 Hz) re-
sults in increased efficiency and, hence, increased
sound pressure level. (A similar effect occurs when
a loudspeaker is placed near a boundary—a wall, a
ceiling, a floor, etc.) In the upper-bass/lower-mid-
range region (typically below 500 Hz), an array of
multiple woofers will have greater directivity (a high-
er Q) than that of a single woofer, resulting in high-
er on-axis sound pressure levels. Because the
equalization of the DMC-1152B controller is tailored
to provide a flat acoustic frequency response with a
single DML-1152A loudspeaker, an over emphasis
of the low and lower-mid frequencies can result
when multiple loudspeakers are assembled togeth-
er. The exact nature of this phenomenon will de-
pend on the details of the array (the number of
loudspeakers, their spacing, the splay angles, prox-
imity to boundaries, etc.) An increase in acoustic
response at these frequencies can result in low-
frequency feedback or unwanted rumble, and is
best dealt with using a graphic or parametric equal-
izer.
SPEAKER INSTALLATION
The DML-1152APF is a flying version of the
DML-1152AP. Each cabinet has a total of six steel-
reinforced aircraft-type pan fittings (three on the top
and three on the bottom). This three-point flying
system makes maximum use of the trapezoidal
cabinets, permitting a wide range of angle adjust-
ment and offering maximum flexibility in array de-
sign and implementation for both the touring sound
company and the sound contractor. The pan fit-
tings mate with the Aeroquip 32343 and 32326
twelve-jaw fittings. Electro-Voice offers the DMS
series of rigging hardware; a complete line of flying
accessories to be used with the DML speaker sys-
tems.
page 15

THE DELTAMAX™ SYSTEM
INSTALLATION (continued)
*** CAUTION ***
The DML-1152APF speaker systems should be
suspended overhead only in accordance with
the procedures and limitations specified in the
DML-1152AF Flying Manual which is packed
with each flying speaker system.
Each DML-1152A speaker system comes with four
rubber feet and mounting screws as accessories for
the user to install as an option if desired. Rubber
feet on the enclosure lessens the possibility of slip-
ping and sliding in applications where the speaker
systems are stacked.
CONTROLLER INSTALLATION
Power Source
The DMC-1152B comes prewired from the factory
for operation at 120 volts. To operate at 240 volts,
the primary wiring of the power transformer must be
altered.
*** CAUTION ***
Hazardous voltages and currents may be en-
countered within the chassis. The service infor-
mation contained within this document is for
use by Electro-Voice authorized warranty sta-
tions and qualified service personnel only.
To change the transformer primary wiring configu-
ration use the following procedure:
1. Unplug the controllers power cord from the ac
power source.
2. Remove the seven screws securing the top
cover. There are two screws on each side, two
Screws on the rear and one screw in the front
panel (center, top).
100 VAC PRIMARY WIRING
Installation
3. Locate the eight voltage select solder cups
near the power transformer. Referring to Table
1, reconnect the leads corresponding to the de-
sired primary voltage.
4. Install the correct line fuse. See values in
Table II.
5. Plug the power cord into an ac outlet and turn
the controller on. Measure the voltage at the
points shown in the PCB diagram. The mea-
sured voltage should be +22 volts. If the mea-
sured voltage is not within 1096 of this value,
turn the unit off and check the connections in
step 3.
6. Reinstall the top cover with the seven screws.
Mounting
The unit is one rack-space high (13/4 in.) and fits a
standard EIA 19-inch rack. To make wiring easier,
mount the controller near the power amplifier(s).
Grounding
A widely accepted grounding technique for audio
systems is the star connection (single-point)
ground. The final configuration will be determined
by the size of the system and the equipment used
in the system. However, the star connection is rec-
ommended as a starting point.
The interconnecting cables of line level equipment,
such as the DeltaMax™ controller should have the
shields connected at one point only, usually the re-
ceiving end of the signal transmission. See Figure
14.
Never lift the third wire safety ground of the ac
power cable. It protects against possible shock
hazard.
220 VAC PRIMARY WIRING
TABLE I
Primary Power Conversion Chart for 100-, 120-, 220- and 240-V, 50/60-Hz Operation
page 16

THE DELTAMAX™ SYSTEM
INSTALLATION (continued)
When deciding how to best ground the controller in
a particular system, note that the controller's input
and output XLR-type connectors have pin 1 refer-
enced to chassis ground through a 20 k resistor
and a .01bF capacitor. This minimizes the possibil-
ity of a ground loop. Circuit ground ties to the chas-
sis ground internally at one point. The input to the
controller is active differential and the output is
transformer isolated.
Ventilation
Adequate ventilation should be proved in the rack
to maintain a reasonable operating temperature.
The ambient temperature inside the rack cabinet
should not exceed 60°C (140°F) under any condi-
tions.
Security
A security cover and attachment screws are sup-
plied to protect the control settings against uninvit-
ed adjustments.
Maintenance
Use a soft damp cloth to clean the unit. No other
maintenance is required.
Installation
Line Fuse,
MDL Series
Slo-Blo
0.25 A/250 V
0.25 A/250 V
0.10 A/250 V
0.10 A/250V
TABLE Il
Main Fuse Selection Guide
page 17

THE DELTAMAX™ SYSTEM Figures
CAO PI CN
~~ e” POWER
AMPLIFIER
DeltaMax™ CONTROLLER
OUTPUT (ONLY ONE
CHANNEL SHOWN)
FIGURE 7 - DeltaMax™ Output Connection
OUTPUTS
SENSE INPUTS
LJ DMC-11528 ОО © (2 ©
LF HE
INPUT CABLE
INPUTS
- + 一 + Е
оо
оо
ES.
QO
HF LF
CHANNEL CHANNEL
HF LF
CHANNEL CHANNEL
TO DML-1152A LF
FIGURE 8 - interconnections for Single Channel Operation
page 18

THE DELTAMAX™ SYSTEM Figure
SENSE INPUTS OUTPUTS INPUT
EE) DMC-11528 оо оо @ Фо
НЕ
GAIN CONTROL
Bus
GAIN
SENSE INPUTS OUTPUTS INPUT
CONTROL
Сг) mese | O O [O O |97869 BUS
HF LF НЕ LF PATCH
a ap E
SENSE LINES
т
4 = ы ue LEFT RIGHT
OO OO
POWER
E
@)
AMPLIFIER
HF
HF
LEFT RIGHT INPUT — INPUT
Lj
сч
TOLEFT 2
DML-1152A HF @-
PIN 2 +
TO RIGHT 0 0
DML-1152A HF
tal
RIGHT НЕ LEFT HF RIGHT LF
OUTPUT = LEFT RIGHT
一 + 一 十
OO OO POWER
AMPLIFIER LE ге
LEFT X RIGHT INPUT — INPUT
TOLEFT
DML-1152A LF
TO RIGHT 0 0
DML-1152A LF ІШ
Ш Ш
=
FIGURE 9 - Interconnection for Stereo Operation
тете 10

Assembly View of P.C. Board
THE DELTAMAX™ SYSTEM
POWER SUPPLY P.C. BOARD
page 20