Crown Audio CH4 Leaflet

Crown International, Inc.

P.O. Box 1000

Elkhart, IN 46515-1000

TEL: 219-294-8200

FAX: 219-294-8FAX

www.crownaudio.com

CH4

08/00                                                            131514-1  

 

For more details refer to the applicable Reference Manual or 

Contact Crown Audio Technical Support. The provided data 

should not be construed as specifications.

Crown is a registered trademark of Crown International, Inc. 

Printed in U.S.A.
© 2000 Crown International, Inc.

This document provides detailed information about the amount of power 

and current drawn from the AC mains by the CH4 amplifier and the 

amount of heat produced under various conditions. The calculations pre-

sented here are intended to provide a realistic and reliable depiction of 

the amplifier. The following assumptions or approximations were made:

•    The  amplifier’s  available  channels  are  loaded  and  full  power  is  being 

delivered.

•    The  amplifier  efficiency  at  standard  1-kHz  power  is  estimated  to  be 

77%.

•    Quiescent power draw is approximately 140 watts.
•    When running at full speed, typical power draw for the internal fan is 

approximately 12 watts.

•    The estimated duty cycles take into account the typical crest factor for 

each type of source material.

•    Duty cycle of pink noise is 50%.
•    Duty cycle of highly compressed rock ‘n’ roll midrange is 40%.
•    Duty cycle of rock ‘n’ roll is 30%.
•    Duty cycle of background music is 20%.
•    Duty cycle of continuous speech is 10%.
•    Duty cycle of infrequent, short duration paging is 1%.

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

The following equation converts power draw in watts to current draw in 

amperes:

The value used for Power Factor is 0.98. The Power Factor variable is 

needed to compensate for the difference in phase between the AC mains 

voltage and current. The following equation is used to calculate thermal 

dissipation:

The value used for inefficiency is 0.23 (1.00–0.77). 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: