Using Audio in or samples then split up stereo signal and do phase lag

#1

Hello,

i am just thinking of what I wanna do later:

Put in an audio source, maybe audio input or a wave file from sd card, then I want to split up the stereo signal into left and right, now I want to manipulate each channel individually, for first try I simply want to add a phaselag of maybe 90°.

Is this easily possible, right now I think so, but I have to try later, amybe someone has already some expirience with that.

I did try once to do 2 sinus oscilators with phase lag, I did not find anything useful back then.

The reason why I am asking, I want to look at the corresponding signal in XY mode of my oscilloscope, and that does only work properly when there are different signals on the left and right channel and phaselag also helps to make the picture move, so I wanna experiment with that.

Thanks a lot.

#2


value 16 on the phase offset corresponds to 90 degrees.

You need to understand the execution order behavior of Axoloti to avoid inserting one-buffer delays. check tutorials/25_execution_order

Shifting a signal with a phase difference of 90 degrees across the spectrum needs a complex filter, can be approximated with a cascade of 1st order allpass filters if I recall correctly. Or a hilbert transformer can split one signal in two 90 degrees out of phase signals. Sorry don't have implementations, though they would be useful additions to the object library.

#3

thanks that did actually do the job pretty easily.

Would love to post some Vid or pics, but cannto do yet.

Anyway its a bit boring, but in this modus i can pretty easily test the XY settings on my oscilloscope, which is more interesting than watching tv :smile:

#4

allpass_phaeshift.jpg1280x776 66.8 KB

I did try the allpass in cascade, it kind of does nothing until you hit the max level on the knob than it does distort the one channel deeply, and indeed kind of switched 90 ° the phase, but the other thing is more usefull.

update one:

I did kind of miss the 1st order point, and indeed you are right, if I only use one allpass, so order of 1 I suppose, it is shifting my signal kind of 90° so yes it works, but still the other solution gives better pictures since it goes once around 360°