Thule PR350 B V350 User Manual
Page 12
___________________________________________________________________________
page 12
A sound wave travels at approx. 340 meter/sec., which is equivalent to:
1 foot in 1 millisecond
or
1 meter in 3 milliseconds
Following example demonstrate how to calculate the delay setting for SL, SR, SC
and C:
From the listening position to each speaker, we measure following distances:
Example Your measurements
Listening position <-> Left speaker:
3.8 m (= 11.4 ft)
Listening position <-> Right speaker:
3.8 m (= 11.4 ft)
Listening position <-> Center speaker:
2.9 m (= 8.7 ft)
Listening position <-> Left surround speaker: 2.1 m (= 6.3 ft)
Listening position <-> Right surr. speaker:
2.1 m (= 6.3 ft)
Listening position <-> Center surr. speaker:
1.8 m (= 6.3 ft)
The delays when measuring the distance in meters are then calculated as:
SL delay :
(L - SL distance) x 3 = (3.8 - 2.1) x 3 = 5.1ms
SR delay :
(R - SR distance) x 3 = (3.8 - 2.1) x 3 = 5.1ms
C delay :
(L - C distance) x 3 = (3.8 - 2.9) x 3 = 2.7ms
SC delay :
(L - C distance) x 3 = (3.8 - 1.8) x 3 = 6ms
or when the distance is measured in feet:
SL delay :
L - SL distance =
11.4 - 6.3 =
5.1ms
SR delay :
R - SR distance =
11.4 - 6.3 =
5.1ms
C delay :
L - C distance =
11.4 - 8.7 =
2.7ms
SC delay :
L - SC distance =
11.4 - 5.4 =
6ms
In this example, we would set the delay to:
SL 5.0ms
C 3.0ms
SR 5.0ms
SC 6.0ms
The above calculations for delay are based on the physical installation and should
be stored as the initial settings in the memory banks (see section 5).
However, at Thule Audio’s experience the delay could be further increased about 0
– 3 milliseconds in the surround speakers from the above calculations, to obtain a
more realistic surround sound image.
For each surround mode the preferred settings should be stored in the memory
banks for automatic reload.