Specifications

5.1-Channel Production Guidelines Production Environment
3-24
two measurements have been made, calculate the required delay settings for the room.
Use the following formula to calculate the delays.
(Distance from L) – (Distance from S) = Surround delay for Dolby Digital
L = Left or Right speaker
S = Left Surround or Right Surround speaker
In the example below, the listening position is 15 feet from the Left (or Right)
speaker and 10 feet from the Surround speakers, so the delay setting for the Surround
channels is five milliseconds for Dolby Digital. This is the correct delay in
milliseconds to program into the decoder.
15 (number of feet from L) – 10 (number of feet from S) = 5 (Surround delay for
Dolby Digital, in milliseconds)
3.5.2 Center Channel Delay
The concept of coincident arrival can also be applied to the adjustment of the Center
channel in Dolby Digital. No delay is required if the Center speaker can be placed at
the same distance from the listener as the Left and Right speakers (in an arc). Thus,
distance C = distance L or R. If the Center speaker is placed closer to or farther from
the listening position than the Left and Right speakers, delay can be added to the
Center channel signal to bring it into acoustic alignment with the Left and Right
speakers. This will electronically move the speaker to its proper position in the room.