Alpine PXA-H700 - Manual (Page 10)

8
-EN
Performing time correction manually
(TCR)/Switching the phase
Because of the particular conditions inside the
vehicle, there are major differences in the
distances between the different speakers and the
listening position. The proper time correction can
be obtained using the automatic time correction
function (“AUTO TCR”), but it is also possible to
calculate the optimum correction values and
eliminate the time error at the listening position
yourself using this function. You can also use this
function to switch the phase.
1
Check that the defeat mode is off.
(See page 28.)
2
Sit in the listening position (the driver’s seat, for
example) and measure the distance (in meters)
between your head and the various speakers.
3
Calculate the difference in distance between the
farthest speaker and the other speakers.
L = (distance of farthest speaker)
– (distance of other speakers)
4
Divide the distances calculated for the different
speakers by the speed of sound (343 m/s
temperature 20
°
C).
This value is the time correction value for the
different speakers.
2.25m
0.5m
5.1ms
• Concrete examples
1. Calculating the time correction value for the
front left speaker on the diagram below.
Conditions:
Distance between farthest speaker and
listening position: 2.25 m (88-3/4")
Distance between front left speaker and
listening position: 0.5 m (20")
Calculation: L = 2.25 m (88-3/4") – 0.5 m (20")
= 1.75 m (68-3/4")
Compensation time = 1.75
÷
343 x 1000
= 5.1 (ms)
In other words, setting the time correction value
for the front left speaker to 5.1 (ms) sets a
virtual distance matching the distance to the
farthest speaker.
The sound is uneven
because the distance
between the listening
position and the different
speakers is different.
The difference in the
distance between the
front left and rear right
speakers is 1.75 meters
(68-3/4"). Time correction eliminates
the difference between
the time required for the
sound from the different
speakers to reach the
listening position.
Setting the time correction
of the front left speaker to
5.1 ms makes it possible
to coordinate the distance
from the listening position
to the speaker.
5
Press the TCR/PHASE button to set the time
correction mode.
Settings/Adjustments
CHANNEL
ENTER
TCR/PHASE
Rotary encoder