I am trying to recreate the Electro-Harmonix Flanger Hoax pedal, and one of its functions shifts phase between 240 and 990 degrees. As far as I can tell, MSP objects can shift phase only up to 360 degrees. Is there any way to shift further than that? Possibly with the delay~ object? How would I calculate the parameters if I were to go this route?

I am trying to recreate the Electro-Harmonix Flanger Hoax pedal, and one of its functions shifts phase between 240 and 990 degrees.  As far as I can tell, MSP objects can shift phase only up to 360 degrees.  Is there any way to shift further than that?  Possibly with the delay~ object?  How would I calculate the parameters if I were to go this route?

shifting-phase-past-360-degrees

How to shift phase on a signal that's not necessarily an oscillator (eg. phasor~, cycle~, etc)? The Flanger Hoax uses a 'fixed phaser' which shifts phase a constant 240 degrees, and a 'swept phaser' which sweeps from 240 to 990 degrees. The phaseshift~ object does not seem to do just this; its middle inlet "sets the frequency at which signals will be shifted by 180 degrees. Signals below this frequency will be shifted less; signals above will

How do I shift phase without phaseshift~? Or what am I not understanding about phaseshift~ from the help file and reference manual?

How to shift phase on a signal that's not necessarily an oscillator (eg. phasor~, cycle~, etc)?  The Flanger Hoax uses a 'fixed phaser' which shifts phase a constant 240 degrees, and a 'swept phaser' which sweeps from 240 to 990 degrees.  The phaseshift~ object does not seem to do just this; its middle inlet "sets the frequency at which signals will be shifted by 180  degrees. Signals below this frequency will be shifted less; signals above will
be shifted more, up to 360 degrees."

How do I shift phase without phaseshift~?  Or what am I not understanding about phaseshift~ from the help file and reference manual?

Degrees are supposed to work with modulo-360 arithmetic. So 360

As Peter says, anything above 360 becomes x%360. But presumably what you mean by this is shifting a signal by 360 is shifting in time by 1 cycle. Shifting 720 is by 2 cycles. Is this what you mean?

Yes, this is what I mean, shifting phase by sometimes more than one cycle. However, it is finding a way of doing this that I am having trouble with. I am phase shifting a signal that does not necessarily come from cycle~ or phasor~ etc.

delay~ seems to be useful for this but I'm not sure how I could go about making the appropriate calculation, since it shifts in number of samples.

phaseshift~ sounds like what I need (in the name at least), but I can't really understand what the following (from the reference manual) means: "Sets the frequency at which signals will be shifted by 180 degrees. Signals below this frequency will be shifted less; signals above will be shifted more, up to 360 degrees."

Yes, this is what I mean, shifting phase by sometimes more than one cycle.  However, it is finding a way of doing this that I am having trouble with.  I am phase shifting a signal that does not necessarily come from cycle~ or phasor~ etc.  

delay~ seems to be useful for this but I'm not sure how I could go about making the appropriate calculation, since it shifts in number of samples.  

phaseshift~ sounds like what I need (in the name at least), but I can't really understand what the following (from the reference manual) means: "Sets the frequency at which signals will be shifted by 180 degrees. Signals below this frequency will be shifted less; signals above will be shifted more, up to 360 degrees."


> Yes, this is what I mean, shifting phase by sometimes more than one

> cycle. However, it is finding a way of doing this that I am having

> trouble with. I am phase shifting a signal that does not necessarily

> delay~ seems to be useful for this but I'm not sure how I could go

> about making the appropriate calculation, since it shifts in number

> phaseshift~ sounds like what I need (in the name at least), but I

> can't really understand what the following (from the reference

> manual) means: "Sets the frequency at which signals will be shifted

> by 180 degrees. Signals below this frequency will be shifted less;

> signals above will be shifted more, up to 360 degrees."

You can also look at allpass~ or at filters in general. The help file 

for biquad~ shows how digital filters are made. With short delay lines 

and feedback. comb~ is also worth to discover...

To look at phase relationships made with biquad~ you can use a 

filtergraph~ with its phase spectrum display...

Jay Bodley schrieb:
> Yes, this is what I mean, shifting phase by sometimes more than one
> cycle.  However, it is finding a way of doing this that I am having
> trouble with.  I am phase shifting a signal that does not necessarily
> come from cycle~ or phasor~ etc.
>
> delay~ seems to be useful for this but I'm not sure how I could go
> about making the appropriate calculation, since it shifts in number
> of samples.

> phaseshift~ sounds like what I need (in the name at least), but I
> can't really understand what the following (from the reference
> manual) means: "Sets the frequency at which signals will be shifted
> by 180 degrees. Signals below this frequency will be shifted less;
> signals above will be shifted more, up to 360 degrees." 

You can also look at allpass~ or at filters in general. The help file 
for biquad~ shows how digital filters are made. With short delay lines 
and feedback. comb~ is also worth to discover...
To look at phase relationships made with biquad~ you can use a 
filtergraph~ with its phase spectrum display...

-- 
Stefan Tiedje------------x-------
--_____-----------|--------------
--(_|_ ----|-----|-----()-------
-- _|_)----|-----()--------------
----------()--------www.ccmix.com


> > delay~ seems to be useful for this but I'm not sure how I could go

> > about making the appropriate calculation, since it shifts in number

Let's say I'm reading a sound file from buffer~ with play~. I want to shift the phase of the sound I am playing. How could I calculate that phase shift using delay~? Is this even possible? Am I confused? Am I speaking nonsense? :)

Some mental block is preventing me from understanding how Hz = 1/second relates to this.

> > delay~ seems to be useful for this but I'm not sure how I could go
> > about making the appropriate calculation, since it shifts in number
> > of samples.
>
> Hz = 1/seconds

Let's say I'm reading a sound file from buffer~ with play~.  I want to shift the phase of the sound I am playing.  How could I calculate that phase shift using delay~?  Is this even possible?  Am I confused?  Am I speaking nonsense?  :)

well if you know the delay time in ms, then u should use mstosamps~ bcos delay takes values as samples of audio... as in the delay~ helpfile!

Quote: laotze wrote on Thu, 31 July 2008 17:16

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> Some mental block is preventing me from understanding how Hz = 1/second relates to this.

the fundamental frequency in Hz of a wave = 1 second/period in seconds.

for example, if the period (1 cycle) of a wave is 0.02 seconds then the frequency is 1s/0.02s or 50 Hz.

this works milliseconds too: 1000ms/20ms = 50Hz

and if you know the fundamental you can calculate the period.

12.5 ms represents 360 degrees here. so for a shift of 1259 degrees at 80 Hz, you go:

1000ms/80Hz = 12.5ms /360 = 0.347222ms *1259 = 43.714998 ms

this way you can calculate the delay you need to create a comb filter with a certain phaseshift at a certain frequency. blend the delay and the direct signal and hear it phase away. now modulate the delay and you have a phasor centered around a certain phaseshift at a certain frequency. which might or might not be what you are after, i'm not sure ;)

Quote: laotze wrote on Thu, 31 July 2008 17:16
----------------------------------------------------
>
> Some mental block is preventing me from understanding how Hz = 1/second relates to this.

I think Stefan is referring to this:
the fundamental frequency in Hz of a wave = 1 second/period in seconds. 

and if you know the fundamental you can calculate the period.
1000ms/80Hz = 12.5ms
12.5 ms represents 360 degrees here. so for a shift of 1259 degrees at 80 Hz, you go: 

i forgot that delay~ needs a value in samples, not in ms.

simply multiply your ms value by SR/1000 to get the delay in samples. like this:

> Let's say I'm reading a sound file from buffer~ with play~. I want

> to shift the phase of the sound I am playing. How could I calculate

> that phase shift using delay~? Is this even possible? Am I

It will be different for different frequencies... In that context phase 

wouldn't be a clear attribute, whereas delay would be...

What is the musical/perceptional result you are after? It depends on 

that what to use or how to address your problem. Phase as such is a very 

Jay Bodley schrieb:
> Let's say I'm reading a sound file from buffer~ with play~.  I want
> to shift the phase of the sound I am playing.  How could I calculate
> that phase shift using delay~?  Is this even possible?  Am I
> confused?  Am I speaking nonsense?  :)

It will be different for different frequencies... In that context phase 
wouldn't be a clear attribute, whereas delay would be...

What is the musical/perceptional result you are after? It depends on 
that what to use or how to address your problem. Phase as such is a very 
abstract mathematical topic...

shifting phase past 360 degrees?