Alpine CDA-137EBT User Manual

e distance between the listener and the speakers in a car vary widely
due to the complex speaker placement. is dierence in the distances
from the speakers to the listener creates a shi in the sounds image and
frequency characteristics. is is caused by the time delay between the
sound reaching the listener's right versus the le ear. To correct this, this
unit is able to delay the audio signal to the speakers closest to the listener.
is eectively creates a perception of increased distance for those
speakers. e listener can be placed at an equal distance between the le
and right speakers for optimum staging. e adjustment will be made for
each speaker in 3.4cm steps.
Listening Position example as follows:
About Time Correction
Adjust the time correction level of the front le speaker to a high value
and the rear right to zero or a low value.
Example 1: Front Left Seat
5.1ms
2.25m
0.5m
e sound is not balanced because the distance between the listening
position and the various speakers is dierent. e dierence in distance
between the front le speaker and the rear right speaker is 1.75 m (68-
7/8"). Here we calculate the time correction value for the front le
speaker in the diagram on the above.
In other words, giving the front le 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
dierences in the time required for the sound to reach the listening
position.
e time of the front le 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.
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
× 1000 = 5.1 (ms)
*1
Speed of sound: 343 m/s (765 mph) at 20°C
Adjust the time correction level of each speaker to almost the same level.
Example 2: All Seats
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 dierence 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 dierent 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
Number
Time Dier-
ence (ms)
Distance (cm)
Distance
(inch)
0 0 .0 0.0 0.0
1 0 .1 3.4 1.3
2 0 .2 6.8 2.7
3 0 .3 10.2 4 .0
4 0 .4 13.6 5 .4
5 0 .5 17.0 6 .7
6 0 .6 20.4 8 .0
7 0 .7 23.8 9 .4
8 0 .8 27.2 10.7
9 0 .9 30.6 12.1
10 1.0 34.0 13.4
11 1.1 37.4 14.7
12 1.2 40.8 16.1
13 1.3 44.2 17.4
14 1.4 47.6 18.8
15 1.5 51.0 20.1
16 1.6 54.4 21.4
17 1.7 57.8 22.8
18 1.8 61.2 24.1
19 1.9 64.6 25.5
20 2.0 68.0 26.8
21 2.1 71.4 28.1
22 2.2 74.8 29.5
23 2.3 78.2 30.8
24 2.4 81.6 32.2
25 2.5 85.0 33.5
26 2.6 88.4 34.8
27 2.7 91.8 36.2
28 2.8 95.2 37.5
29 2.9 98.6 38.9
30 3.0 102.0 40.2
31 3.1 105.4 41.5
32 3.2 108.8 42.9
33 3.3 112.2 44.2
34 3.4 115.6 45.6
35 3.5 119.0 46.9
36 3.6 122.4 48.2
37 3.7 125.8 49.6
38 3.8 129.2 50.9
39 3.9 132.6 52.3
40 4.0 136.0 53.6
41 4.1 139.4 54.9
42 4.2 142.8 56.3
43 4.3 146.2 57.6
38
-EN

Alpine CDA-137EBT Specifications

General

Brand	Alpine
Model	CDA-137EBT
Category	Car Receiver
Language	English