ISO 2969:2015 pdf free

ISO 2969:2015 pdf free.Cinematography一B-chain electro-acoustic reponse of motion-picture control rooms and indoor theatres
The measured level in any 1/3-octave band can be used directly if it exceeds the background noise in the band by at least 10 dB. If the background noise is between 4 dB and 10 dB below the test signal, the measurement may be corrected using the techniques described in ANSI/ASA S1.13 (see Table 4).
A system for playing contemporary stereo films will generally employ a minimum of four wide-range channels: screen left, centre, and right loudspeaker systems, and a surround channel loudspeaker system employing a number of individual loudspeakers spaced around the left wall, rear wall and right wall of the room in such a way as to achieve uniform coverage. Most rooms where digital soundtracks are played have the surround channel separated into two or three separate channels, left rear and right rear,or left rear, centre rear and right rear. Such systems are frequently built up out of left wall, left rear, right rear and right wall banks of speakers. Most of these rooms also have a dedicated low-frequency channel using one or more sub-woofers. Some rooms may be equipped with two intermediate screen channels,one between left and centre, and one between centre and right. Regardless of the number of channels,each channel or bank shall be measured separately in turn and the equalization adjusted if necessary.
The electroacoustic response of the B-chain for screen and surround channels shall be listed in Table 1 and shown in Figure 5 within the tolerances given. Note that this characteristic is for a medium-sized theatre (with between, say 200 and 500 seats) with average reverberation behaviour. See A.5 for a discussion of modifications required to this characteristic for larger and smaller spaces and for surround loudspeaker arrays.
It is recognized that there are a few older sound systems still in use in theatres which cannot meet the centreline of the standard over the fully extended frequency range. The response standard has been updated over the years to account for the changes in technology which permit a wider frequency range,but note the precaution on excessive equalization of older systems in A.6.ISO 2969 pdf download.