TAS5534 Loudness Processing Block Diagram

Hi,

We have not obtained your reply yet, are looking forward to receiving your favorable reply.

Best Regards,
Kato

Hi, Kato-san,

We will get back to you shortly on this.

-d2

Hi Don-san,

We are looking forward to your reply for this issue.

Best Regards,
Kato

Hi Kato-san,

The V should not be there. It a mistake. Sorry for the delay to get the answer for you.

reg,

Paul.

Hi Paul-san,

Thank you for your reply quickly.
We could understand that the addition of "V" is not correct.
So, if we remove the addition of "V" about figure 3-11 of data sheet, we believe that the equation of loudness function is as below.

Audio Out = Audio In * V [1 + H(z) * f(v)]

On the other hand, we seem that it is about ALE 5.2 as below.

Audio Out = Audio In * [V + H(z) * f(v)]

Which the equation is correct?
Could you please advise us about it?

Best Regards,
Kato

Hi Paul-san,

We found that there is described regarding the loudness compensation block diagram on page 3-25 of TAS3103A data sheet.
If the loudness function of TAS5534 and TAS3103A is same, we believe that the equation of ALE 5.2 and TAS3103A is correct.
Is our understanding correct?
The equation of TAS3103A is as below.

audio out = [audio in * volume_setting] + [audio in * F(s)biquad * f(volume_setting)]

Could you please tell us about it?

Best Regards,
Kato

Hi Paul-san,

We are looking forward to your reply for this issue.

Best Regards,
Kato

Hi, Kato-san,

please see attached for loudness description.

0312.Loudness Compensation.docx

reg,

Paul.

Hi Paul-san,

Thank you for explaining.
We would like to know the meaning of the "Maximum individual* master volume".
Is this the value that multiplied the channel volume by the master volume?
Then, the path that multiplying the "Maximum individual* master volume" is not found.
In addition, the format number of loudness parameters is different on page 30 of TAS5534 data sheet(e.g. offset parameter and log parameter).
Is this a mere typo?
Could you please describe block diagram using a calculating formula?

Best Regards,
Kato

Hi Paul-san,

Do you have any updates for this issue?

Best Regards,
Kato

Hello Kato-san:

As explained in this thread: http://e2e.ti.com/support/amplifiers/audio_amplifiers/f/6/p/324345/1185441.aspx#1185441

the "Max Volume" used in the loudness block is derived from the master volume and the individual channel volume multiply with the modulation index limit setting.  The block diagram is too general (high level) to show the max volume in the loudness block.

Best regards,

Tuan

Hi Tuan-san,

Thank you for explaining.
Since the loudness algorithm of TAS5534 and TAS3103A is same, I believe that the equation and the block diagram of ALE 5.2 and TAS3103A are correct.
The equation of TAS3103A is as below.

audio out = [audio in * volume_setting] + [audio in * F(s)biquad * f(volume_setting)]

Could you please give me your advice if I have any misunderstanding ?

Best Regards,
Kato

Hello Kato-san:

Yes.  But, perhaps I need to ask you a few questions so that we can give a better answer.  Going back and forth with questions may not help the customer resolving their problems.

1.  What does the customer need with loudness parameters?  What is the purpose for this?

2.  Does the customer want to port TAS3103A loudness biquads to TAS5534? Or did they find some differences between the two devices?

3.  Or does the customer want to modify his/her current loudness settings?

Thank you.

Best regards,

Tuan

Hi Tuan-san,

Thank you for your quickly reply.
I am so sorry to have confused you and answer your questions as below.

Q1.
Since a calculating formula was different from the loudness function block diagram of TAS5534 that is described in a data sheet,
I received an inquiry from our customer.
Therefore, our customer would like to know the correct calculating formula and loudness function block diagram.

Q2.
Our customer who asked about difference between the loudness algorithm of TAS5538 and TAS3103 is different from our customer who asked about Q1.
Since I suggested ALE5.2 to our customer, it was asked you a question simply.

Q3.
Our customer will optimize it about it.

So, could you please let me know about Q1?

Best Regards,
Kato

Hi Tuan-san,

Thank you for your cooperation.
I will confirm the data sheet of TAS3101A and inform our customer about the equation.

Best Regards,
Kato