TAS5828M: About DSP memory settings

Ryu Yamashita

Part Number: TAS5828M
Other Parts Discussed in Thread: TAS5805,

Tool/software:

Hi team,

I have a few questions.

In the Equalizer, EBE/DDE/DEQ, and DRC setup screens as shown below, there is a place to set a biquadratic filter.
I don't know how to calculate the filter coefficients for each filter type.
Can you please provide me with a formula for calculating the filter coefficients or a reference that I can refer to?

I do not understand how to set the Threshold Low, Threshold High, and Enrgy to DSP memory in the Threshold Setting below.
I assume that some conversion formula is used to calculate the values set for DSP memory based on the values set here, but I cannot derive the conversion formula.

I do not understand how to set each value of ratio and time constatnt below to DSP.
I assume that some conversion formula is used to calculate the DSP memory settings based on the values set here, but I cannot derive the formula.

Also, when I change Threshold, offset, and Ratio, the other values also change, but I would like to know what rules are used to change them.

Best Regards,
Ryu.

1 month ago

0 Ramsey Foote 1 month ago

TI__Expert 5855 points

Hi Ryu,

This app note includes sections on how the biquads and DRC work on the TAS5805 which work the same as the TAS5828M. You can use the I2C log function of PPC3 to determine what values are sent to the device when you change a parameter.

Regards,

Ramsey

0 Ryu Yamashita 1 month ago in reply to Ramsey Foote

Expert 2680 points

Hi Ramsey,

I checked the documents but could not find the relevant section.
Also, I have checked the I2C logs, but the values are different from those set in PPC3, so I would like to know the internal calculation formula.

Best Regards,
Ryu.

0 Ramsey Foote 1 month ago in reply to Ryu Yamashita

TI__Expert 5855 points

Hi Ryu,

The calculation will change depending on the format of the values and is not always intuitive. You should use PPC3 to generate the I2C commands to match with what configuration you want.

Regards,

Ramsey

0 Ryu Yamashita 1 month ago in reply to Ramsey Foote

Expert 2680 points

Hi Ramsey,

We would like to configure the software without PPC3.
Is it possible to publish those formulas?

Best Regards,
Ryu.

0 Ramsey Foote 1 month ago in reply to Ryu Yamashita

TI__Expert 5855 points

Hi Ryu,

Unfortunately, this is not something I can provide. PPC3 should be used to configure the software.

Regards,

Ramsey

0 Ryu Yamashita 1 month ago in reply to Ramsey Foote

Expert 2680 points

Hi Ramsey,

I understand that you cannot give us the formula.
I would like to be able to change the settings from my smart phone, but it is difficult to install PPC3 on my smart phone, can I get the library etc.?

Best Regards,
Ryu.

0 Ramsey Foote 1 month ago in reply to Ryu Yamashita

TI__Expert 5855 points

Hi Ryu,

PPC3 does not have a phone installer. Even if it did, there would not be a way to communicate to the board as the EVMs do not have any wireless connectivity and need the micro-USB cable to communicate. You should use a computer to install and use PPC3.

Regards,

Ramsey

0 Ryu Yamashita 29 days ago in reply to Ramsey Foote

Expert 2680 points

Hi Ramsey,

I am thinking of incorporating it into my application instead of EVM.
I wanted to be able to freely change filters and other settings from my phone.

Best Regards,
Ryu.

+1 Jesse Ji 29 days ago in reply to Ryu Yamashita

TI__Genius 15480 points

hi Ryu

usually, if customer want to realize the filter changing in their own device, they might need to consider processing the signal with their own calculation formula to get the signal be processed.

our ppc3 can generate the filter config parameter, customer can also store those paras, and sent the para to amps to let the config be changed.

tks

jesse

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TAS5828M: About DSP memory settings