View Single Post
  #7  
Old 10-01-2008, 03:13 PM
danijel danijel is offline
Member
 
Join Date: Jun 2008
Location: Serbia
Posts: 160
Default Re: Dolby Facility Requirements

4.0 Technical Requirements for Studios to Obtain
Dolby Certification for Commercials and Trailers
only


4.1. The first essential requirement for the dubbing theatre is to monitor Dolby mixes
correctly (all formats, Dolby Stereo, Dolby Digital and Dolby Digital Surround
EX) as well as the possibility to play their own and other studios' 6 and 2 track
printing masters. To this end you will need to install a Dolby cinema processor
type CP650S1. All versions will provide inputs for stereo solar cells, full matrix
decoding, 1/3-octave equalisation for loudspeaker calibration, master monitor
level control, Surround EX and all digital processing. Balanced or AES/EBU
input/output lines are available as options.

4.2. Optical replay of the analogue and digital track is not a requirement but is
recommended in order to check the quality of an answer print. This will require a
solar cell and bracket assembly to be added to the projector or sound follower
and a digital reader. Your CP650 may also require an additional module. Please
inform us if you wish to have optical replay facilities.

4.3. The picture must be projected onto a screen (preferably perforated or woven)
TV monitors are not acceptable.

4.4. Screen and surround speakers and amplifiers must be capable of providing a
frequency response to ISO2969 and, with the requirements of Dolby Digital in
mind, must be able to provide an SPL of 105dBC for peak levels, after acoustic
calibration, without distortion (Appendix A). Theatre type speakers (pressure
drivers with suitable horns) will be required in large rooms and these should
have electronic crossovers. The screen speakers must be at a height to give
good coverage in the mixing and listening area. Speaker systems with bass
management are not suitable. When projecting a picture the left and right
speakers should be inside the edge of the picture area and ideally provide
between a 45 degree angle with the mixing position. We recommend that the
mixing position be placed 2/3 back from the screen and we recommend that the
screen is at least 5 metres from the mixer.
The Dolby Studio Approval Calculator (Commercials and Trailers only) should
be used to verify loudspeaker and amplifier performance capabilities.
Suitable test material is available to check monitor headroom capability (“Jiffy”
test film tone sweep test and a pulsed short duration 0dBfs pink noise test).
Please note that Dolby level pink noise, 85dBC, equates to around -14dBfs.
1 See Appendix B for selection chart
Rev 13 Page 6 of 10

4.5. The acoustics of the mixing room must conform to the acoustic characteristics
shown below in Figure 1. Ambient noise levels must not exceed NC-25 as
measured according to ISO 9568 Background acoustic noise levels in theatres,
review rooms and dubbing rooms.
Figure 1 Reverberation Time

4.6. Two track “Printing Masters” must be on .wav, RDAT or Hi-8 format (DTRS).
Six-track “Printing Masters” must be on .wav or Hi-8 format (DTRS).

4.7. Mixing consoles must have a minimum of 20 input channels and 6 main output
groups. Mixing consoles designed for music mixing may need modification to
obtain correct insertion points for the Dolby encoder/decoder. The console
should have at least two panoramic controls to move sounds between at least
four channels and preferably more.

4.8. Level standardisation at –20dB below MSB or clip in the console main outputs
and recorders is essential. You may wish to check with the manufacturer that
digital and line levels conform to accepted standards i.e. +4dBu or 0dBu line
level for –20dB MSB internal console level and that the meters read –20dB.

4.9. It is a requirement by most organising bodies and Dolby Laboratories that the
level of commercials & trailers is controlled and monitored using a Leq (m) meter
(British Standard BS 5550-7.4.2). Commercials & Trailers made above the
requirement will be rejected.
Reply With Quote