Arduino Controlled Bass Mid Treble and input selector

My LC75341 project was a bit of a disappointment. It was working ok but it only offers bass and treble controls. The frequency response is not that good. It has very limited controls. I decided to stop that project because it is not what I am looking for. Now after lots of research, I stumble upon this digitally controlled bass mid treble IC from ST. What is great is that it has 7 band spectrum analyzer feature and a differential input. Plus it also has Q and frequency control and a subwoofer output. This is almost exactly what I want to do.

Note: This is an on-going project. At this moment it is on design stage.

About the circuit

The heart of the circuit is a TDA7419 chip. It is a digitally controlled tone control for audio application. It has the following features:

● Input Multiplexer
– QD / SE: quasi-differential stereo inputs, with selectable single-ended mode
– SE1: stereo single-ended input
– SE2: stereo single-ended input
– SE3 / AC2IN: stereo single-ended input / HPF filter input
– In-Gain 0 to 15dB, 1dB steps
– internal offset-cancellation (AutoZero)
– separate second source-selector
● Mixing stage
– mixable to front speaker-outputs
● Loudness
– 2nd order frequency response
– programmable center frequency (400Hz/800Hz/2400Hz)
– 15 dB with 1 dB steps
– selectable low and high frequency boost
– selectable flat-mode (constant attenuation)
● Volume
– +15 dB to -79 dB with 1 dB step resolution
– soft-step control with programmable blend times
● Bass
– 2nd order frequency response
– center frequency programmable in 4 steps (60 Hz/80 Hz/100 Hz/200 Hz)
– Q programmable 1.0/1.25/1.5/2.0
– DC gain programmable
– -15 to 15 dB range with 1 dB resolution
● Middle
– 2nd order frequency response
– center frequency programmable in 4 steps (500Hz/1KHz/1.5KHz/2.5KHz)
– Q programmable 0.5/0.75/1.0/1.25
– DC gain programmable
– -15 to 15dB range with 1dB resolution
● Treble
– 2nd order frequency response
– center frequency programmable in 4 steps (10KHz/12.5KHz/15KHz/17.5KHz)
– -15 to 15dB range with 1dB resolution
● Spectrum analyzer
– seven bandpass filters
– 2nd order frequency response
– programmable Q factor for different visual appearance
– analog output
– controlled by external serial clock
● Speaker
– 4 independent soft-step speaker controls, +15dB to -79dB with 1dB steps
– Independent programmable mix input with 50% mixing ratio for front speakers
– direct mute
● Subwoofer
– 2nd order low pass filter with programmable cut off frequency
– single-ended mono output independent soft-step level control, +15dB to -79dB
with 1dB steps
● Mute functions
– direct mute
– digitally controlled Soft-mute with 3 programmable mutetimes(0.48ms/0.96ms/123ms)
● Effect
– gain effect, or high pass effect with fixed external components

I would be perfect if it had a sound compressor feature but it is way better than what the LC75341 can offer. What i like about it is that it has programmable center frequency and Q for each bass, mid and treble. It also has a 7 band spectrum analyzer output it will be easy to integrate the spectrum analyzer without going through the FFT code.

(Basic circuit of TDA7419)

Circuit Design

This is on-going, I am quite busy right now so it will take some time for me to be able to finish this project. I am planning to control it with arduino nano. I also plan to have a WiFi connection so you can be able to control it using your phone. That’s just a plan for now.