Service Manual
AT235
VI
6.3 Reference equivalent threshold values for transducers
Impedance - frequencies and intensity ranges
AT235 Maximums IMP
TDH39
DD65v2
EARtone 3A / IP30 IPSI
DD45
Center Reading
Reading
Reading
Reading
Reading
Freq.
Tone
NB
Tone
NB
Tone
NB
Tone
NB
Tone
NB
[Hz]
[dB HL] [dB HL] [dB HL] [dB HL] [dB HL] [dB HL] [dB HL] [dB HL] [dB HL] [dB HL]
125
80
65
85
70
100
85
70
60
75
60
250
100
85
100
85
110
100
85
75
100
85
500
120
100
110
95
115
105
100
85
120
100
750
120
105
115
100
120
110
100
85
120
105
1000
120
105
115
100
120
110
105
90
120
105
1500
120
105
115
100
120
110
110
90
120
100
2000
120
105
115
95
120
110
105
90
120
100
3000
120
105
115
100
120
110
95
90
120
105
4000
120
105
110
95
120
105
100
85
120
105
6000
120
100
100
85
105
100
85
80
110
90
8000
105
95
95
70
90
85
80
75
105
95
10000
WB
-
115
-
115
-
115
-
95
-
120
LP
-
120
-
115
-
120
-
100
-
120
HP
-
115
-
115
-
120
-
95
-
120
Table 1
