Dolby Laboratories CP65 manual Re S, e. Surround Equalization Alignment Cat. No, Action

5-32

B-Chain Alignment Procedures

e. Surround Equalization Alignment (Cat. No. 441)

5-33

B-Chain Alignment Procedures

e. Surround Equalization Alignment (Cat. No. 441)

Step

No.

1

2

3

Re

S

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

Action Indication

RIGHT

OFF

04	Dolby Stereo
	A-type

MONO SURROUND STEREO SURROUND

88 dBC						85 dBC
F
OF						30
0		0	0		0
8	7			50	4
			6

Dolby

Notes

If your CP65 does not contain the Cat. No. 441 Surround Equalizer and Subwoofer Card, skip this paragraph and go directly to page 5-42, Adjustment of Surround Delay. The CP65 will function without the Cat. No. 441 card, but the surround frequency response cannot be equalized.

The surround equalizer on the Cat. No. 441 card consists of:

•A parametric mid-band section with variable cut, bandwidth, and center frequency.

•Shelving type Bass and Treble controls.

All connections established in the previous procedure still apply to the surround equalization alignment. Confirm that the microphone is in the position defined on page 5.6. Ensure that format 04 is selected.

Note: The Cat. No. 441 can be configured for either Mono or Stereo surround operation using link J3 ( See page 2-5 for details). If Mono operation is selected then an identical signal will be fed to both Ls and Rs outputs in all formats. If only one power amplifier is to be used for the surround channel then the Ls should be used. If more than one surround amplifier is to be used, both outputs may be used to feed, for example, balcony and ground floor. The separate level controls and equalizers may then be used to compensate for differences caused by the different acoustic environments of the two areas. If stereo operation is selected a stereo surround signal will be fed to the surround channels when format 10, Dolby Stereo SR• D is selected.

If the surround speakers are wired for stereo operation or both surround outputs are in use switch off (or disconnect the input to) the right surround amplifier or amplifiers.

Turn on the S switch on the Cat. No. 85C pink noise generator. Be sure that format 04 is selected.

Adjust the Ls ( left surround) gain control on the Cat. No. 242 B-Chain card for a sound pressure level of approximately 85 dBC in the theatre. If only one surround output is used set the level to 88 dBC.