Dolby Laboratories CP65 manual 14 → 21 R 14 →, Setting Room Equalization b. Adjusting L,C,R Gain

Page 48

		5-18
a. Setting Room Equalization		B-Chain Alignment Procedures
a. Setting Room Equalization
b. Adjusting L,C,R Gain
Step	Action	Indication
No.

21

4 5 6

3 7

2 8

1 9

0 10

22REPEAT

L 14 → 21 R 14 → 21

23	4	5	6
23	4		6
3			7
2			8
1			9

010

b.Adjusting L,C,R Gain

5-19

B-Chain Alignment Procedures

a. Setting Room Equalization b. Adjusting L,C,R Gain

Notes

Turn off the pink noise on the center channel. Turn the fader to 0 or press the Mute button.

Disconnect the center equalizer module from the extender and then remove the extender from the CP65. Re-install the cover on the module and plug it back in. Repeat for the left and right channel equalizer modules, using the Cat. No. 67 extender.

Turn the fader back to ‘7’ or press the mute button again.

b. Adjusting L,C,R Gain

1

Cat. No. 242

mono eq

mono

gain L non-sync

R

L

signal C present R

Ls gnd

L

C

test points R

Ls

L

C

gain

R

Ls

Dolby

85 dBC

Turn the pink noise switches L, C, R on one at a time and adjust the L, C and R gain controls on the Cat. No. 242 B-Chain Card so that each channel produces 85dBC in the theatre, as measured by the sound level meter at the standard location described in Step 15 above. Be sure that the front panel FADER is set to 7, format 04 is selected, and the subwoofer is off during this step.

OFF				0
0	70 6	50	0	3
8	0		4

Image 48

Contents Model CP65 Cinema Processor Dolby Laboratories Inc Headquarters Table of Contents Section Reference Block Diagrams Introduction Page Section Equipment Required Smpte Buzz Track Stereo Optical Surround Level Cat. No Jiffy Test Film Cat. No 2 Listen . . . Film Cat. NoSection Initial SET-UP and Installation Voltage Acceptable Setting Voltage Range Fuse Type Next, check the jumpers in the following locations Cat. No , Power Supply Module Cat. No , B-Chain CardCat. No , Control Logic Card J2 NON-SYNCCP65 Backplane Standard CP65 or CP65ACP65-300 High Low Subwoofer subwoofer Output output These Modules are Necessary for Bypass Operation Slot Card Function Cat. No Two-channel NoiseReduction Module Channel DecoderContains a semi-regulated power supply with Voltage Setting Fuse Type InternationalIEC Notices HUM Problems Room lighting dimmer controls SCR-TYPEPage Section AN Overview of the Alignment Procedure Aligning the B-ChainPage Page Section Chain Alignment Preliminary Procedures Action IndicationLamp Voltage Optical Preamplifier Adjustments Chain Alignment Procedures Optical Preamplifier Adjustments 222 CAT. no Test Film Oscilloscope Traces Repeat CAT no Repeat 1 →Magnetic Preamplifier Adjustments Magnetic Alignment 100mV Section Chain Alignment Setting Room Equalization BypassLoudspeakers and Crossovers Amplifiers GeneralChain Alignment Procedures OffRepeat ActionChain Alignment Procedures Setting Room Equalization Do not adjust Paul Setting Room Equalization b. Adjusting L,C,R Gain 14 → 21 R 14 →Setting Mono Gain 79 dBCChain Alignment Procedures Subwoofer Alignment Cat. No 90 dBC 85 dBCFrom Step NoSelect format 04 Dolby Stereo A-Type Same AS 441Surround Equalization Alignment Cat. No Surround Equalization Alignment Cat. No Notes Cat. No 441Desired 88 dBC Bypass Adjustment of Surround Delay Thumbwheel SwitchMsec Setting Chain Alignment Procedures Adjustment of Bypass Gain Xx dBCFrom Xx dBC -3 dB Yy dBCAdjustment of Non-sync Gain Press the format 60 non sync switchAuto Freq Adjustment of Mono Gain and Equalization Notes Repeat page 5-20 StepChain Alignment Procedures Final Checks Press the format 04 Dolby Stereo A-type switchSection Reference Diagrams Cat. No Dual Noise Reduction Module Inputs Cat. No Optical Bass Extension and Surround Equalizer Card Cat. No B-Chain Facilities Card Cat. No Power Supply Card Cat. No Transformer Module Inputs Cat. No Control Logic Card Cat. No +24V +15V 15V +12B+15M Appendix a Checking Phasing of Speakers Appendix B Effect of Changes in Slit Height on Slit Losses Appendix C CP65M Mono Instructions OperationCat. No a Circuit Description Schematic Cat. No a Appendix D Backplane Connections List Terminal Block TB3Connector J18