Example 1: Front Left Seat; Example 2: All Seats - Alpine CDA-117 Owner's Manual

Example 1: Front Left Seat

Adjust the time correction level of the front left speaker to a high value
and the rear right to zero or a low value.
0.5m
2.25m
The sound is not balanced because the distance between the listening
position and the various speakers is different.
The difference in distance between the front left speaker and the rear
right speaker is 1.75 m (68-7/8").
Here we calculate the time correction value for the front left speaker in
the diagram on the above.
Conditions:
Farthest Speaker - listening position : 2.25 m (88-9/16")
Front left speaker - listening position : 0.5 m (19-11/16")
Calculation: L = 2.25 m - 0.5 m = 1.75 m (68-7/8")
Time correction = 1.75 ÷ 343
Speed of sound: 343 m/s (765 mph) at 20°C
In other words, giving the front left speaker a time correction value of
5.1 ms makes it seem as if its distance from the listener is the same as the
distance to the farthest speaker.
Time correction eliminates the differences in the time required for the
sound to reach the listening position.
The time of the front left speaker is corrected by 5.1 ms so that its sound
reaches the listening position at the same time as the sound of other
speakers.

Example 2: All Seats

Adjust the time correction level of each speaker to almost the same level.
1
Sit in the listening position (driver's seat, etc.) and
measure the distance (in meters) between your head and
the various speakers.
2
Calculate the difference between the distance correction
value to the farthest speaker and the other speakers.
L = (distance to farthest speaker) - (distance to other speakers)
These values are the time correction values for the different
speakers. Setting these values to make each sound reach the
listening position at the same time as the sound of other
speakers.
Time Correction Value List
Delay Time Differ-
Number ence (ms)
0 0.0
1 0.1
2 0.2
40
-EN
5.1ms
*1
× 1000 = 5.1 (ms)
Distance
Distance (cm)
(inch)
0.0 0.0
3.4 1.3
6.8 2.7
Delay Time Differ-
Number ence (ms)
3 0.3
4 0.4
5 0.5
6 0.6
7 0.7
8 0.8
9 0.9
10 1.0
11 1.1
12 1.2
13 1.3
14 1.4
15 1.5
16 1.6
17 1.7
18 1.8
19 1.9
20 2.0
21 2.1
22 2.2
23 2.3
24 2.4
25 2.5
26 2.6
27 2.7
28 2.8
29 2.9
30 3.0
31 3.1
32 3.2
33 3.3
34 3.4
35 3.5
36 3.6
37 3.7
38 3.8
39 3.9
40 4.0
41 4.1
42 4.2
43 4.3
44 4.4
45 4.5
46 4.6
47 4.7
48 4.8
49 4.9
50 5.0
51 5.1
52 5.2
53 5.3
Distance
Distance (cm)
(inch)
10.2 4.0
13.6 5.4
17.0 6.7
20.4 8.0
23.8 9.4
27.2 10.7
30.6 12.1
34.0 13.4
37.4 14.7
40.8 16.1
44.2 17.4
47.6 18.8
51.0 20.1
54.4 21.4
57.8 22.8
61.2 24.1
64.6 25.5
68.0 26.8
71.4 28.1
74.8 29.5
78.2 30.8
81.6 32.2
85.0 33.5
88.4 34.8
91.8 36.2
95.2 37.5
98.6 38.9
102.0 40.2
105.4 41.5
108.8 42.9
112.2 44.2
115.6 45.6
119.0 46.9
122.4 48.2
125.8 49.6
129.2 50.9
132.6 52.3
136.0 53.6
139.4 54.9
142.8 56.3
146.2 57.6
149.6 59.0
153.0 60.3
156.4 61.6
159.8 63.0
163.2 64.3
166.6 65.7
170.0 67.0
173.4 68.3
176.8 69.7
180.2 71.0