Hi there

I have been struggling with this for a bit.

I'm trying to make a patch that pans the sound through 4 channels so as to make it sound like a mono sound is spinning around the listener.

To do this, I decided to have 2 oscillators at a phase difference of 90 degrees and the snapshot object to convert the signal to messages to control the front and back, right and left stereo pairs.

How do you shift the phase of osc~? I can't seem to figure it out.

any help is greatly appreciated.

jf

A phasor creates a phase index i, normalised 0 to 1 (where 1 is 2*pi radians or 360 degrees).

Taking the cosine of this gives us the usual sinusoidal wave, x = cos(i)

Taking the cosine of 0.5 - i gives us the phase shifted signal, cos(0.5 - = sin(i) = 90 degree phase

Furthermore, cos(1-i) is a 180 degree shift that puts them completely out of phase.

Also, using a delay of one quarter period (unreliable in practice) - try it and see why

Hilbert transform, half the real positive part (for complex signals - hard to understand) - ask a real mathematician (I am an imaginary one).

http://www.pdpatchrepo.info/hurleur/phase-shift2.pd

Shift the phase of osc~ with a float message (0-1) in the right inlet. Also, I would try four [osc~], each shifted 90 degrees modulating the amplitude of each channel. Bang the messages in unison to syn them up. One channel would look like;

.25
|
|
[osc~ 0.5]
|
|
|
| [r~ channel1]
| |
| |
[*~ ]
|
|
[dac 1]

As usual, obi has the true answer. However, here's what I was thinking (much less graceful) -- attachment

http://www.pdpatchrepo.info/hurleur/pan.pd

not inelegant Nestor, you've demonstrated the important point I missed, that it is better to use the audio signal directy as the gain control than convert to message domain with [snapshot~] as per Mr Fulfords original proposal. Afaik those two [osc~] units will stay in the same phase relationship indefinitely too.

a.

thanks for all the help, I've got something I can work with now. The two suggestions go a long way. I've kept with the snapshot only because I'm using a constant-power pan object which makes it easier on me, but harder on my computer and probably less accurate.

thanks again
j

Hi all,

I see the topic is quite old, but hey - it's worth a try!

I am trying to write a patch that takes the outputs of three filters - LPF, HPF and BPF, runs them through individual delays/phase shifts and takes them to the stereo (for the moment) out. The point is to create a beam steer at separate frequency bands and thus focus the required sound at a said position without spilling it outside of it.

I tried using the example file uploaded by nestor, however, it did not quite work as expected.

I have attached a copy of my patch. As you may notice there are some irregularities, but for the moment I am more interested in:

a) making the shift stay in one place instead of circling continuously; and
being able to control each filter/delay individually.

Any help is well appreciated!

Cheers,

L

http://www.pdpatchrepo.info/hurleur/Filters_+_delay_v5.5.pd