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Setting the Time Correction
■ About Time Correction
The distance between the listener and the speakers in a car vary
widely due to the complex speaker placement. This difference in
the distances from the speakers to the listener creates a shift in the
sounds image and frequency characteristics. This is caused by the
time delay between the sound reaching the listener's right versus the
left ear.
To correct this, this unit is able to delay the audio signal to the
speakers closest to the listener. This effectively creates a perception
of increased distance for those speakers. The listener can be placed
at an equal distance between the left and right speakers for optimum
staging. The adjustment will be made for each speaker in 3.4 cm
steps.
Example 1. Listening Position: 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.
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* × 1,000 = 5.1 (ms)
* 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. Listening Position: 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
Time
Distance
Distance
Difference
(cm)
(inch)
(msec)
0.0
0.0
0.0
0.1
3.4
1.3
0.2
6.8
2.7
0.3
10.2
4.0
0.4
13.6
5.4
0.5
17.0
6.7
0.6
20.4
8.0
0.7
23.8
9.4
0.8
27.2
10.7
0.9
30.6
12.1
1.0
34.0
13.4
1.1
37.4
14.7
1.2
40.8
16.1
1.3
44.2
17.4
1.4
47.6
18.8
1.5
51.0
20.1
1.6
54.4
21.4
1.7
57.8
22.8
1.8
61.2
24.1
1.9
64.6
25.5
2.0
68.0
26.8
2.1
71.4
28.1
2.2
74.8
29.5
2.3
78.2
30.8
2.4
81.6
32.2
2.5
85.0
33.5
2.6
88.4
34.8
2.7
91.8
36.2
2.8
95.2
37.5
2.9
98.6
38.9
3.0
102.0
40.2
3.1
105.4
41.5
3.2
108.8
42.9
3.3
112.2
44.2
3.4
115.6
45.6
3.5
119.0
45.9
3.6
122.4
48.2
3.7
125.8
49.6
3.8
129.2
50.9
3.9
132.6
52.3
4.0
136.0
53.6
4.1
139.4
54.9
4.2
142.8
56.3
4.3
146.2
57.6
4.4
149.6
59.0
4.5
153.0
60.3
4.6
156.4
61.6
4.7
159.8
63.0
4.8
163.2
64.3
4.9
166.6
65.7
Time
Distance
Distance
Difference
(cm)
(inch)
(msec)
5.0
170.0
67.0
5.1
173.4
68.3
5.2
176.8
69.7
5.3
180.2
71.0
5.4
183.6
72.4
5.5
187.0
73.7
5.6
190.4
75.0
5.7
193.8
76.4
5.8
197.2
77.7
5.9
200.6
79.1
6.0
204.0
80.4
6.1
207.4
81.7
6.2
210.8
83.1
6.3
214.2
84.4
6.4
217.6
85.8
6.5
221.0
87.1
6.6
224.4
88.4
6.7
227.8
89.8
6.8
231.2
91.1
6.9
234.6
92.5
7.0
238.0
93.8
7.1
241.4
95.1
7.2
244.8
96.5
7.3
248.2
97.8
7.4
251.6
99.2
7.5
255.0
100.5
7.6
258.4
101.8
7.7
261.8
103.2
7.8
265.2
104.5
7.9
268.6
105.9
8.0
272.0
107.2
8.1
275.4
108.5
8.2
278.8
109.9
8.3
282.2
111.2
8.4
285.6
112.6
8.5
289.0
113.9
8.6
292.4
115.2
8.7
295.8
116.6
8.8
299.2
117.9
8.9
302.6
119.3
9.0
306.0
120.6
9.1
309.4
121.9
9.2
312.8
123.3
9.3
316.2
124.6
9.4
319.6
126.0
9.5
323.0
127.3
9.6
326.4
128.6
9.7
329.8
130.0
9.8
333.2
131.3
9.9
336.6
132.7
67
-EN
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