4-4.
Set the average time required to detect the ambient noise
levels with the sensor microphone.
Adjustable range: 10 s, 20 s, 30 s, 1 min, 5 min
4-5.
Adjust the ratio of ambient noise level variation to output level
variation.
For example, if the ratio between N and S is set to be 3:3, the
output volume level goes up by 3 dB when the ambient noise
level increases by 3dB.
Adjustable range: 6:3, 5:3, 4:3, 3:3, 3:4, 3:5, 3:6
When the adjustment mode is set to ADVANCED:
4-6.
Finely adjust the reference value (ZERO level) of the set
SENSOR level.
If the reference value* differs from the actual minimum noise
level, there may be a situation that the output sound is
extremely loud though the ambient noise is quiet.
In such cases, correct the reference value of SENSOR level.
* The minimum noise level that has been measured in Step 4-1
is defined as reference value "ZERO level."
The explanations below are based on the assumption that the maximum output level (MAX LEVEL),
minimum output level (MIN LEVEL), and gain ratio (GAIN RATIO) are as follows: MAX LEVEL = 0 dB,
MIN LEVEL = –12 dB, and GAIN RATIO = 3:3.
[When the preset minimum ambient noise level is the same as the actual level]
No correction is needed.
The diagram below shows the relationship among the ambient noise level, SENSOR level, and output
level.
19
S A M P L E
T I M E
2 0 s e c
G A I N
R A T I O
N : S
=
3 : 3
A D J . Z E R O
S :
+ 1
0 d B
L : – 1 8
From the previous page
To page 21
11
10
9
8
7
6
5
4
3
2
1
0
0
dB
–3
–6
–9
–12
80 dB
68 dB
Noise range in which you desire
to control the output level.
Ambient noise level
SENSOR level
Output level
The output level is properly adjusted in response
to changes in ambient noise level.
ZERO level set by following MIN NOISE SET
instruction (Step 4-1)
