PUREPATHCONSOLE: Question about Dynamic EQ

Florentin Ménage

(EDIT)

Dear TI team,

I am currently trying to configure a system with "Dynamic EQ" to reduce rub&buzz effects.

I was wondering what represents the phase diagram associated with the magnitude.

Indeed, the presented phase diagram does not look like a PEQ phase but the magnitude that is represented looks like a negative amplitude PEQ filter

Best regards

over 1 year ago

0 Jeff McPherson over 1 year ago

TI__Mastermind 33570 points

Hi Florentin,

Which TI audio device are you working with? Also a picture of the plots you are seeing would be very helpful.

Thank you,
Jeff McPherson

0 Florentin Ménage over 1 year ago in reply to Jeff McPherson

Prodigy 20 points

Hi Jeff,

I am working with the TAS2563QFN EVM

I wonder what the phase pointed by the arrow represents.

Thanks!

0 Jeff McPherson over 1 year ago in reply to Florentin Ménage

TI__Mastermind 33570 points

Hi Florentin,

Just to clarify, you're expecting a phase plot like the one below (circled in blue)?

The plot you are seeing is the Dynamic EQ, rather than a typical Parametric EQ. The Dynamic EQ works like a compressor, where the EQ band only attenuates when the input crosses the magnitude plot. I will double check with our DSP experts to clarify why the phase plots are different.

Thank you,
Jeff McPherson

0 Florentin Ménage over 1 year ago in reply to Jeff McPherson

Prodigy 20 points

Hi Jeff, exactly; I would expect a phase plot like the one circled in blue.

I understand the idea behind the Dynamic EQ but I still don't understand what represents the phase plot that is shown in this section.

Thank you for your help,

Florentin Ménage

0 Jeff McPherson over 1 year ago in reply to Florentin Ménage

TI__Mastermind 33570 points

Hi Florentin,

I checked with our designers, and the phase plot in the DEQ can still be read like any other phase plot (phase shift vs frequency). However the DEQ doesn't use a simple filter that would result in the phase response circled in blue. It's a combination of all-pass and band-pass filters, where the band-pass filters change gain dynamically based on signal level. This results in a different phase response than the one you'd expect from a simple notch filter.

Best regards,
Jeff McPherson

0 Florentin Ménage over 1 year ago in reply to Jeff McPherson

Prodigy 20 points

Hi Jeff,

Thank you for your answer!

Best regards,

Florentin Ménage

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PUREPATHCONSOLE: Question about Dynamic EQ