Crown ma-36x12 Manual Suplementario

8 Ohm

L  O  A  D

50%

40%

30%

20%

10%

1190

970

750

530

310

1622

1359

1096

833

570

1663

1348

1034

719

405

551

457

362

267

172

1994

1613

1232

852

471

2583

2128

1673

1218

762

12.0

9.7

7.5

5.3

3.1

16.7

13.5

10.4

7.2

4.1

20.0

16.2

12.4

8.6

4.7

Duty

Cycle

AC Mains

Power

Draw

(Watts)

btu/hr

Current Draw (Amps)

6.2

5.1

3.9

2.8

1.6

8.7

7.1

5.4

3.4

2.1

10.4

8.5

6.5

4.5

2.5

4 Ohm

2 Ohm

409

342

276

210

144

kcal/hr

2188

1812

1436

1059

683

651

536

422

307

192

100-120 V

230 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal/hr

100-120 V

230 V

Thermal Dissipation

btu/hr

Current Draw (Amps)

kcal/hr

100-120 V

230 V

Thermal Dissipation

AC Mains

Power

Draw

(Watts)

AC Mains

Power

Draw

(Watts)

Here are the equations used to calculate the data presented in Figure 1:

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:

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:

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%

Total measured output power

from all channels (watts)

Thermal

Dissipation

(btu/hr)

=

+

Quiescent Power

Draw (watts)

.35

x

Amplifier Efficiency (.65)

(

)

x 3.415

Current Draw

(amperes)

=

AC Mains Power

Draw (watts)

x

AC Mains

Voltage

Power

Factor (.83)

AC Mains Power

Draw (watts)

=

Total output power with all

channels driven (watts)

x Duty

Cycle

Amplifier Efficiency (.65)

+ Quiescent Power

Draw (watts)

Total output power with all

channels driven (watts)

Thermal

Dissipation

(btu/hr)

=

+

Quiescent Power

Draw (watts)

x Duty

Cycle

Amplifier Efficiency (.65)

(

)

x 3.415

.35

x

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

For more details refer to the applicable Operation 
Manual or contact Crown

®

 Factory Service. The 

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                                              138416-1