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Hi,

I made a little experiment.

I put two sine oscillators with the same parameters each in a separated track.
Then I put a "Scope" and a "Phase Meter" in the Master track in order to observe the output signal.

I've noticed this strange behaviour:

When I pan one track to extreme left or right I can see a phase shift of about 1/3 PI (my guess) between left and right channel.

I was expecting to see that one channel has a signal lower than the other one, but I was expecting with the same phase, so two identical signals, but just with different levels.

Maybe it's correct, but I cannot understand the mathematical reason behind that.

I've attached a snapshot to clearify what I've done.

Any opinion/explanation about that?

Thank you.

Attachments
Screen Shot 2017-08-15 at 01.52.19.jpg
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by Jemusic on Mon Aug 14, 2017 7:18 pm
You are doing this test incorrectly. By using two tone generators. They wont be in sync. What makes you think they will be?

I have checked this with one tone generator only and there are no phase shifts from what I can see panning either Centre Hard L or Hard R.

Specs i5-2500K 3.5 Ghz-8 Gb RAM-Win 7 64 bit - ATI Radeon HD6900 Series - RME HDSP9632 - Midex 8 Midi interface - Faderport 2/8 - Atom Pad/Atom SQ - HP Laptop Win 10 - Studio 24c interface -iMac 2.5Ghz Core i5 - High Sierra 10.13.6 - Focusrite Clarett 2 Pre & Scarlett 18i20. Studio One V5.5 (Mac and V6.5 Win 10 laptop), Notion 6.8, Ableton Live 11 Suite, LaunchPad Pro
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by Morticia on Tue Aug 15, 2017 1:35 am
Jemusic wroteYou are doing this test incorrectly. By using two tone generators. They wont be in sync. What makes you think they will be?
I have checked this with one tone generator only and there are no phase shifts from what I can see panning either Centre Hard L or Hard R.

:thumbup:

A perfect illustration right there as to why competent, experienced professional test engineers get paid a pretty good living.

AMD Phenom quad core | 8 GB RAM | Roland UA-25 EX audio interface | Radeon HD 2400 Pro | Win 8.1 x64 | Studio One Pro v3.5.6 x64

"The queen of spades is a friend of mine, the queen of hearts is a bitch
someday when I clean up my mind, I'll find out which is which"
Gram Parsons
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by killkrt on Tue Aug 15, 2017 1:41 am
Jemusic wroteYou are doing this test incorrectly. By using two tone generators. They wont be in sync. What makes you think they will be?


Because when both tracks are panned to center I can see in the Scope and in the Phase Meter that they are perfectly in sync.
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by Jemusic on Tue Aug 15, 2017 2:48 am
Yes that may be just a fluke. With one test tone generator I can see no phase shifts. It would be pretty bad if there was a phase shift due to panning.

I have got a real CRO as well which can be dual trace. When I send the test tone generator direct out to a send and hence a physical output I can always see that as a reference. I can also monitor the main outs as well on the other CRO channel. NO phase shifts.

You are chasing your tail here with two test tone generators.

Specs i5-2500K 3.5 Ghz-8 Gb RAM-Win 7 64 bit - ATI Radeon HD6900 Series - RME HDSP9632 - Midex 8 Midi interface - Faderport 2/8 - Atom Pad/Atom SQ - HP Laptop Win 10 - Studio 24c interface -iMac 2.5Ghz Core i5 - High Sierra 10.13.6 - Focusrite Clarett 2 Pre & Scarlett 18i20. Studio One V5.5 (Mac and V6.5 Win 10 laptop), Notion 6.8, Ableton Live 11 Suite, LaunchPad Pro
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by Morticia on Tue Aug 15, 2017 3:01 am
@ the O.P.

If there * was * a phase issue invoked by panning, why hasn't there been multiple reports of this by users ?
It would have been blindingly obvious to the many S1 users who run pro studios, without doing random (and erroneous) stuff (it is not testing) with two sine wave generators, before now.

What you are doing is fundamentally flawed.
You need a single stereo signal from a single source in order to demonstrate that you are starting from a point of absolutely no phase issues to begin with.

AMD Phenom quad core | 8 GB RAM | Roland UA-25 EX audio interface | Radeon HD 2400 Pro | Win 8.1 x64 | Studio One Pro v3.5.6 x64

"The queen of spades is a friend of mine, the queen of hearts is a bitch
someday when I clean up my mind, I'll find out which is which"
Gram Parsons
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by killkrt on Tue Aug 15, 2017 3:18 am
Yes, I got it, if I bounce the two tracks I can see the expected behaviour.

Anyway I was not trying to imply that S1 has a wrong panning implementation (that I know it's a basic functionality), but I was wondering why my little experiment was not working... Now I got it, I was doing in a wrong way ;) It's clear that different instances of tone generator are not in sync.

Thank you.
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by Jemusic on Tue Aug 15, 2017 3:26 am
Which brings up another point. If there were multiple tone generators perhaps some form of syncing would be good but not overall a necessity.

If you want to get a test tone into multiple places at once, one has to be creative and use only one generator and find a way to distribute the audio around to multiple destinations. That will always ensure that the phase relationships will be correct.

Specs i5-2500K 3.5 Ghz-8 Gb RAM-Win 7 64 bit - ATI Radeon HD6900 Series - RME HDSP9632 - Midex 8 Midi interface - Faderport 2/8 - Atom Pad/Atom SQ - HP Laptop Win 10 - Studio 24c interface -iMac 2.5Ghz Core i5 - High Sierra 10.13.6 - Focusrite Clarett 2 Pre & Scarlett 18i20. Studio One V5.5 (Mac and V6.5 Win 10 laptop), Notion 6.8, Ableton Live 11 Suite, LaunchPad Pro

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