All pass filter ???

[jbrs128]

I read that these exists. But i do not know still what's the use?

Very strange. Does anyone have a clue?

[Andre]

All pass filter? What is the use of this? Where did you read it.

[jbrs128]

I was googling around one night and found it.
I do not really remember when and where and for what.

[methos]

It is a filter that actually filters no frequency range, but gives a phase shift only.

[SiEger]

And what is phase shift if i may? Sorry for the interrupt 

[Erkeli]

Phase shift is when for example, during time, the sine wave starts a little bit slower or faster than normal. If for example you have a sine wave of 1 Hz and it starts from 0 on time, with phase shift you have the same sine wave but it starts a little bit more on the right, at 1/4 PI for example...

[Andre]

Yep. i searched the internet. Frequency shifter is also called all pass filter...

[jbrs128]

You are absolutely right. Thank you for your help!