ISO 8622:1998

INTERNATIONAL IS0
STANDARD 8622
Second edition
1998-03-I 5
Cinematography - Magnetic sound
records on 70 mm motion-picture release
prints with magnetic stripes - A-chain
reproduction characteristics
Cinkma tographie - Enregistrements sonores magnktiques sur copies
d ’exploitation sur film 70 mm 21 pistes magnetiques - Caractkristiques de
transfer? de la chalne A
Reference number
IS0 8622: 1998(E)
IS0 8622: 1998(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be represented
on that committee. International organizations, governmental and non-
governmental, in liaison with ISO, also take part in the work. IS0 collab-
orates closely with the International Electrotechnical Commission (IEC) on
all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 8622 was prepared by Technical Committee
I SOmC 36, Cinematography.
This second edition cancels and replaces the first edition (IS0 8622:1990),
clause 2 and subclause 3.5 (note 2 added) of which have been technically
revised.
Annex A forms an integral part of this International Standard.
0 IS0 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
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Printed in Switzerland
ii
INTERNATIONAL STANDARD o Iso IS0 8622: 1998(E)
Cinematography - Magnetic sound records on 70 mm
motion-picture release prints with magnetic stripes -
A-chain reproduction characteristics
1 scope 3 Definitions
This International Standard specifies the A-chain electrical For the purposes of this International Standard, the following
frequency response characteristics for magnetic sound repro- definitions apply.
duction in motion-picture control rooms and indoor theatres. It
is also intended for use, in conjunction with IS0 2969, in the
3.1 complete sound reproduction system: A system
standardization of recording monitor and reproduction charac-
used for the playback of motion-picture records (see figure 1)
teristics of motion-picture sound in studio dubbing theatres,
in dubbing theatres, review rooms, and indoor theatres; by
review rooms and indoor theatres.
convention it consists of an “A-chain and a B-chain ”.
This International Standard covers that part of the motion-
3.2 type D sound track: A sound record with a charac-
picture sound system from the transducer to the input ter-
teristic normally only used with monophonic photographic
minals of the main fader, and should be read in conjunction
motion-picture prints.
with IS0 8590, which defines the recorded characteristics for
35 mm and 70 mm magnetic striped prints.
3.3 type II sound track: A sound record which is intended
for playback over a theatre B-chain system aligned to curve N
of IS0 2969.
2 Normative references
3.4 type Ill sound track: A monophonic or stereophonic
The following standards contain provisions which, through
magnetic or photographic sound record which is intended for
reference in this text, constitute provisions of this International
playback over a theatre B-chain system aligned to curve X of
Standard. At the time of publication, the editions indicated
IS0 2969.
were valid. All standards are subject to revision, and parties to
agreements based on this International Standard are encouraged
A type Ill sound track will normally require decoding with a
to investigate the possibility of applying the most recent
suitable electronic noise reduction system.
editions of the standards indicated below. Members of IEC and
IS0 maintain registers of currently valid International Standards.
3.5 A-chain (transducer system): The “A” part of a
motion-picture sound system as shown in figure 1, which
IS0 2969 : 1987, Cinematography - B-chain electro-acoustic
extends from the transducer(s) to the input terminals of the
response of motion-picture control rooms and indoor tbea tres
main fader.
- Specifications and measurements.
IS0 8395:1995, Cinematography - Test films for the
NOTES
reproduction of 70 mm motion-picture release prints with
magnetic stripes - Specifications.
1 It is customary for the A-chain to contain the necessary deemphasis
network for the playback of type II magnetic sound tracks when being
IS0 8590:1994, Cinematography - Audio records on 70 mm
reproduced over a B-chain aligned to curve X as defined in IS0 2969.
motion-picture release prints with magnetic stripes -
The Achain will also contain noise reduction decoding circuitry if
Recorded characteristic.
required for the playback of type Ill sound tracks.
2 It has been shown that a low-frequency time constant of infinity
should be used for best headroom versus frequency of the medium. It
is recognized, however, that it is necessary for the immediate future to
continue to add low frequency pre-emphasis of 3 180 us, because much
theatre equipment cannot meet the tolerances of this International
Standard when using a time constant of in
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