Setup with a real time analyzer (rta), Calibration tool – Extron Electronics SSP 7.1 User Guide User Manual
Page 101
5.
Calculate the delay time (in ms) for each speaker, where:
Delay Time = Delay Distance / Vs
NOTE: The constant Vs (the speed of sound) is 0.343 m/ms or 1.12533 ft/ms.
6.
For SIS commands, the delay time must be converted to units of 0.1 ms:
SIS Delay time = Delay Time (per ms) x 10
7.
Compile the information into a table (if possible, use a spreadsheet program to carry out
the calculations automatically). An example, using typical values, is given below:
Speaker
Channel
Measured Distance (ft)
Delay (ft)
Delay Time
(ms)
SIS Delay
Time
Left
12.00 (furthest speaker)
0.00
0.0
0
Right
11.00
1.00
0.9
9
Center
10.50
1.50
1.3
13
Left Surround
8.25
3.75
3.3
33
Right Surround 7.50
4.50
4.0
40
Left Back
6.13
5.87
5.2
52
Right Back
7.50
4.50
4.0
40
Table 4.
Calculating Speaker Delays for SIS commands
8.
Use these SIS Delay Time values when entering SIS commands to compensate for
speaker delay where there are no Lip Sync effects (see Speaker Delay Settings).
Setup with a RTA Calibration Tool
1.
Pick an ideal central location on which all speaker output signals converge.
2.
Place the microphone from the RTA at ear level in the convergence location.
3.
Play the audio source. This can be an analog source, provided by the RTA, or a digital
source, provided by a test CD.
4.
Use SIS commands to change the listening mode for the input signal to “Mono to All.”
If necessary, configure the mono source to Left, Right, or, if using an analog input, Left +
Right.
5.
Use SIS commands to mute or unmute specific output channels.
6.
Use the RTA to measure the outputs of each channel.
7.
Calculate the speaker with the longest delay (normally recorded in ms)
8.
Calculate the Delay Time (in ms) and the SIS Delay Time for each speaker and compile
the values in a table as described in the “Two Person Setup” section.
NOTE: The RTA provides Delay Times in ms, so there are no columns for Measured
Distance (ft) or Delay (ft).
9.
Use these SIS Delay time values when entering SIS commands, to compensate for
speaker delay where there are no Lip Sync effects (see Speaker Delay Settings).
SSP 7.1 • SIS Commands
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