M61508FP
2. Loudness Gain Setting
Lower Figure is Structure of Loudness Circuit.
VIN
10
+
–
R
V1
+
–
VOUT
VOLUME 1
R
R
+
–
R
LOUDNESS
FILTER
(Gv = 0 dB)
V2
LOUDNESS VOLUME
Output Voltage (VOUT) of Setting Structure of Upper Figure
It is noted as Volume 1 Output Voltage = V1, Loudness Filter Output Voltage = V2, VOUT and Gv (Boost quantity) is
given at the lower formula
VOUT = V1 + V2 (Vrms)
(V1 + V2)
Gv = 20 log
– (Volume 1 attenuation quantity) (dB)
VIN
ex.) VIN = 1 Vrms/60 Hz, Volume1 = –30 dB,
Output Volutage and Boost Quantity of 60 Hz of Loudness Volume = –20 dB setting
From: Volume1, Loudness Volume attenuation quantity
Become: V1 = 31.6 mVrms
V2 = 100 mVrms
If the sub situdes the equation for the upper formula,
the following equation is given,
Gv
Volume 1 = –30 dB
VOUT = 31.6 m + 100 m
= 131.6 mVrms
Frequency (Hz)
(31.6 m + 100 m)
Gv = 20 log
– (–30 dB)
1
=12.4 dB is obtained
In the item, the Loudness Gain Setting example is shown, when Volume 1 fixation and doing the Loudness Volume
variably. Please refer to Plan.
REJ03F0203-0201 Rev.2.01 Mar 31, 2008
Page 21 of 24
RENESAS [ RENESAS TECHNOLOGY CORP ]
