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TLV320AIC34: ADC Filter usage

Tzviel Lemberger
Prodigy 190 points
Other Parts Discussed in Thread: TLV320AIC34

Hello,

I want to improve my sound sampling quality by using filters on the Analog samples.

Can someone please point out if it is possible to activate LPF on ADC route? In the specification it is only stated how to use HPF.

When used only HPF, I can still hear static noise after the recorded noise was suppressed.

BTW -

I am using Matlab record command with the following configuration:

audiorecorder(44100,16,1,1)

 

  • 0
    TI__Guru* 84915 points

    Hi, Tzviel,

    The TLV320AIC34 can use the effects block in applications where record-only is selected (DAC powered down). The filtering blocks can be used as high-pass, low-pass and band-pass filters. Please take a look of the DIGITAL AUDIO PROCESSING FOR RECORD PATH section for details. If you have questions about it, please let me know.

    Best regards,

    Luis Fernando Rodríguez S.

  • 0 in reply to Luis Fernando Rodriguez S.
    Prodigy 190 points

    Thanks Luis, this was very helpful.

    I want to ask you one extra question about recording path please:

    I am using 4 microphones to record, connected to Line 1 (R and L) and Line 2 (R and L).

    In order to connect them to the ADC record route, I have attached Line 1 R and Line 2 L to Left ADC and the other two connected to Right ADC.

    What I want to do now is to differentiate between these audio signals, meaning subtract between the two input signals so the output of each ADC will be one signal calculated from the 2 analog input subtraction.

    Can you please say if this is done by default when configuring the channel as differential or if extra configuration is needed?

  • 0 in reply to Tzviel Lemberger
    TI__Guru* 84915 points
    Hi, Tzviel,

    You only need to configure the channel as differential. The 'M' input will be subtracted from the 'P' input . For example, if LINE1L is configured as differential, LINE1LM_A will be subtracted from LINE1LP_A .

    Best regards,
    Luis Fernando Rodríguez S.
  • 0 in reply to Luis Fernando Rodriguez S.
    Prodigy 190 points

    Hi Luis,

    Thank you for your answer, but that is not what I meant, let me clarify:

    What I want to do is to subtract between 2 microphone input (each input is a 'P' & 'M' pair) in the record path, and I am interesting to know if this configuration is possible.

    Best Regards!

    Tzviel

  • 0 in reply to Tzviel Lemberger
    TI__Guru* 84915 points
    Hi, Tzviel,

    Unfortunately, the only way to subtract two inputs is from the differential pair 'P' and 'M' as I described before. Only a codec with miniDSP or an external circuitry could substrate both signals

    Best regards,
    Luis Fernando Rodríguez S.