Crown Macro-Tech MA-36X12 Supplementary Manual

MA-36x12
The information provided on this page is calculated data based on driv-
ing both channels to rated output using the 1 kHz Maximum Average
Power rating method.
Other parameters used in calculation include a conservative idle current
estimate of 90 watts and a conservative estimate of effeciency at 65%.
Information is provided only for getting an idea of current draw and heat
produced. Actual performance will vary depending on environment, pro-
gram material, load, signal, and AC mains voltage and frequency.
Values of calculated current draw are intended to represent average draw
corresponding to the thermal breaker requriements that should be met to
handle the amplifier as a load on the AC mains.
Peak current draw with dynamic program material may be significantly
higher. Thermal information is provided to assist with calculating air
conditioning needs. The data here should not be construed as specifica-
tions.
Duty cycle of various program material:
Individual speech: 10%
Acoustic/chamber music: 20%
Full-range rock music: 30%
Compressed rock music: 40%
Pink noise: 50%
8 Ohm
AC Mains
Current Draw (Amps)
Power
Duty
Draw
Cycle
100-120 V 230 V
(Watts)
50% 1190 12.0
40% 970 9.7
30% 750 7.5
20% 530 5.3
10% 310 3.1
M A C R O - T E C H S E R I ES

AC Power Draw and Thermal Dissipation

AC Mains
Thermal Dissipation
Power
Draw
btu/hr kcal/hr
(Watts)
6.2 1622 409 1663
5.1 1359 342 1348
3.9 1096 276 1034
2.8 833 210 719
1.6 570 144 405
A Harman International Company
Crown International, Inc.
1718 W. Mishawaka Rd.
Elkhart, IN 46517-9439
TEL: 574-294-8200
FAX: 574-294-8FAX
www.crownaudio.com
Here are the equations used to calculate the data presented in Figure 1:
AC Mains Power
Draw (watts)
The quiescent power draw is a maximum value and includes power drawn by the fan. The
following equation converts power draw in watts to current draw in amperes:
The value used for Power Factor is 0.83. The Power Factor variable is needed to compen-
sate for the differnece in phase between the AC mains voltage and current. The following
equation is used to calculate thermal dissipation:
(
Total output power with all
Thermal
channels driven (watts)
Dissipation =
(btu/hr)
The value used for inefficiency is 1.00-efficiency. The factor 3.415 converts watts to btu/
hr. Thermal dissipation in btu is divided by the constant 3.968 to get kcal. If you plan to
measure output power under real-world conditions, the following equation may also be
helpful:
(
Total measured output power
Thermal
Dissipation =
(btu/hr)
Macro-Tech 36x12
L O A D
4 Ohm
Current Draw (Amps) Thermal Dissipation
100-120 V 230 V btu/hr kcal/hr
16.7 8.7 2188 551
13.5 7.1 1812 457
10.4 5.4 1436 362
7.2 3.4 1059 267
4.1 2.1 683 172
For more details refer to the applicable Operation
Manual or contact Crown
provided data should not be construed as specif-
ciations.
Crown and Crown Audio are registered trade-
marks of Cown international, Inc. Printed in
U.S.A.
®
© 2005 Crown Audio , Inc.
04/05
Total output power with all x Duty
channels driven (watts) Cycle
+ Quiescent Power
=
Amplifier Efficiency (.65)
AC Mains Power
Draw (watts)
Current Draw
=
(amperes)
AC Mains Power
x
Voltage Factor (.83)
x Duty
.35
x
Quiescent Power
Cycle
+
Draw (watts)
Amplifier Efficiency (.65)
x .35
Quiescent Power
from all channels (watts)
+
Draw (watts)
Amplifier Efficiency (.65)
2 Ohm
AC Mains
Current Draw (Amps) Thermal Dissipation
Power
Draw
100-120 V 230 V btu/hr
(Watts)
1994 20.0 10.4 2583
1613 16.2 8.5 2128
1232 12.4 6.5 1673
852 8.6 4.5 1218
471 4.7 2.5 762
®
Factory Service. The
138416-1
Draw (watts)
)
x 3.415
)
x 3.415
kcal/hr
651
536
422
307
192