Dolby Laboratories CP65 manual Same AS, 441

Page 54

5-30

B-Chain Alignment Procedures

d. Subwoofer Alignment (Cat. No. 441)

5-31

B-Chain Alignment Procedures

d. Subwoofer Alignment (Cat. No. 441)

Step			Action
No.			Action
No.
14		Cat. No.
14		441
	signal
	present
		tp
Subwoofer		on
Subwoofer		cut
		cut
	auto	freq	Dolby
	off	Q
n-sync	opt gain
surr	mag/dig
gain	gain
Surround	treble
Surround		cut
	mid	freq
Left		Q
Left		bass
		bass
		tp
	treble
Surround		cut
Surround	mid	Q
	mid	freq
Right		bass
		gain
		gnd
	signal
	present

15

10 Dolby Stereo

Digital

		Cat. No.
16		441
16
	signal
	present
		tp
Subwoofer		on
Subwoofer		cut
		cut
	auto	freq
	off	Q	Dolby
		Q	Dolby
n-sync	opt gain
surr	mag/dig
gain	gain
Surround	treble
Surround		cut
	mid	freq
Left		Q
Left		bass
		bass
		tp
	treble
Surround		cut
Surround	mid	Q
	mid	freq
Right		bass
		gain
		gnd
	signal
	present

Indication

dB +10

+5

SAME AS 12

0

–5

–10

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5 kHz

	dB
	+10
auto
subwoofer
off	+5
	+5

														0
					auto
			subwoofer											–5
					off									–10




.05	.1	.2	.4				.8				1.6	3.15	6.3	12.5 kHz

dB +10

+10 dB

+5

0

–5

–10

.05

.1

.2

.4

.8

1.6

3.15

6.3

12.5 kHz

Notes

Adjust the optical gain control on the Cat. No. 441 card so that the average level of the bands from the subwoofer is at the same level on the analyzer screen as you noted for the center channel in the previous step.

Place the Le toggle switch on the Cat. No. 85C card in the OFF (center) position and place the C (center channel) toggle switch in the ON position.

Note the change in the average level of the bands from 20 Hz to 100 Hz when the subwoofer switch on the Cat. No. 441 is switched between OFF and AUTO. There should be a level INCREASE when it is switched to AUTO. The subwoofer is out of phase with the front channels if you do not see this level increase. Reverse the subwoofer(s) speaker connections.

Re-select Format 10.

Adjust the mag/dig gain on the Cat. No. 441 so that the level of the bands from the subwoofer increases 10 dB above the level in the previous step.

The subwoofer alignment is completed.

Image 54

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 Reduction Module Slot Card Function Cat. NoTwo-channel Noise 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