User Manual

Multichannel Monitoring Tutorial Booklet (M2TB) rev. 3.5.2

Masataka Nakahara : SONA Corporation

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Incidentally, Rec. ITU-R BS. 775-1 gives examples of multiple speakers used as surround speakers, and it

is stated that in this case, these speakers should be placed in the range of 60˚–150˚ symmetrically between

left and right.

[Fig. 25] Rec. ITU-R BS. 775-1; Four surround loudspeakers

3-3-3. Direct surround and diffuse surround

The advantage of direct surround is that it excels in precise reproduction of a sound field. For example, a

placement such as ITU-R is ideal for reproducing a live recording in a concert hall. Recent research has

confirmed the effectiveness of the ITU-R placement in reproducing a diffuse sound field [3].

For the above reasons, direct surround, and the ITU-R placement in particular, is often used as the

production environment for musical content such as DVD-Audio and Super Audio CD. In broadcasting

stations as well, there is a tendency for a direct surround environment compliant with Rec. ITU-R BS.

775-1 to be used as the production environment.

On the other hand, diffused surround excels in delivering ambient or fly-over sounds, and allows surround

panning to move an audio source in a 360˚ path, and is therefore often used as the production environment

for multi-channel media that accompanies video.

Its compatibility with both 6.1ch playback and 5.1ch playback is a reason why it is favored as a post-

production environment. In particular, this playback environment is a necessity for film productions.

Due to the fact that most productions created in diffused surround do not exhibit significantly different

playback images when different surround speaker placements are used, diffused surround is often used as

the environment for efficiently producing “general purpose” program material.

As standard, the Yamaha DM2000, DM1000, and 02R96 digital consoles support both direct surround

and diffused surround by allowing up to two speakers be used for each of LS and RS (you can also use

one speaker for each). In addition, these surround speakers can be automatically routed to appropriate

surround channel following any changes in the channel format (3-1, 5.1, 6.1).

RS2

60°

150°

LS2

LS1

RS1