Power Driver Integrated Full Digital Audio Amplifier
NTP-8230
Figure 17. Post Bi-Quad Filter Structure
For the enhancement of 3D effect or redirection of Bass signal back into Main channel, Ch3 fire back
structure is integrated like Figure 17.
9.5. Loudness Control
NTP-8230 provides loudness control function using post Bi-Quad filter chains. Loudness control
means the compensation of frequency characteristics in low volume level to fit the acoustic
characteristics of human ears
There are 3 Bi-Quad filters for loudness gain per each channel. To download a loudness gain of each
Bi-Quad, the page flag register 0x7E should be set as same in the case of downloading the filter
coefficients. The loudness gain values are applied for both channel 1 and 2 and when downloading the
loudness gain values, a user should set the register 0x7E as 0x03.
BQ ROM Address
loudness gains of CH1/CH2
0x3E
0x3F
0x40
register Address 0x7E= 0x03 case
L1
L2
L3
BQ ROM Address
0x1F
loudness gains of CH3
0x1E
L1
0x20
L3
register Address 0x7E= 0x04 case
L2
Table 4. Address for Loudness Gain
Copyright ⓒ NeoFidelity, Inc.
Document Number: DS8230 draft ver. 0.1
Page 20
2011-01-11