Invert button on External Audio Effect...why use it?

[Simonsez2389]

Hi,

I'm using the External Audio Effect on a return track to route audio to and from a Strymon Big Sky. It's great.
But I'm seeing an invert phase option and I'm wondering, why would I use this?
I tried going 100% dry on the BS and I definitely heard phasing, but when I inverted, I just heard slightly different phasing. So it didn't seem to work?
100% wet on BS and 100% wet on the effect doesn't have this problem because it's all different audio.
But I'd like to know, just to learn.

Thanks

[Stromkraft]

I'm seeing an invert phase option [on External Audio Effect] and I'm wondering, why would I use this?
I tried going 100% dry on the BS and I definitely heard phasing, but when I inverted, I just heard slightly different phasing. So it didn't seem to work?

Sometimes inverting a signal is the quickest fix to adjust for phasing issues. Sometimes it's not enough, which is what you found out.

Do you have any enabled sends on the track/return that handles the External Audio Effect or in the signal path? If so, that may be enough to cause phase issues. Just disable the sends so Live doesn't have to take additional processing into account, which would add at least one sample of processing.

[Simonsez2389]

Do you have any enabled sends on the track/return that handles the External Audio Effect or in the signal path? If so, that may be enough to cause phase issues. Just disable the sends so Live doesn't have to take additional processing into account, which would add at least one sample of processing.

Not sure I follow this 100% but I disabled all of the sends on my Big Sky return track, and all of the sends on my audio track (except for B which is sending the audio to the Big Sky return track) and didn't hear a difference in the audio.

[fishmonkey]

phase inversion is a pretty blunt instrument.

it's not surprising that disabling the sends didn't make an audible difference, since 1 sample of latency is a very tiny amount.

[Stromkraft]

phase inversion is a pretty blunt instrument.

it's not surprising that disabling the sends didn't make an audible difference, since 1 sample of latency is a very tiny amount.

It is a tiny amount, but sometimes this is the reason you got phasing issues when you don't have to. Always worth thinking about IMHO. Unless you need sends on a return of course.

[Stromkraft]

Do you have any enabled sends on the track/return that handles the External Audio Effect or in the signal path? If so, that may be enough to cause phase issues. Just disable the sends so Live doesn't have to take additional processing into account, which would add at least one sample of processing.

Not sure I follow this 100% but I disabled all of the sends on my Big Sky return track, and all of the sends on my audio track (except for B which is sending the audio to the Big Sky return track) and didn't hear a difference in the audio.

It's mainly the return track that is of interest.

If I had a problem I probably would have tried a test and would put the output cable to the big sky directly back to input of the return instead so that the signal goes out and right back in again. Then set this dry return to exactly the same level as the original signal — I use Sonalksis FreeG to measure levels — and put Utility:Phase Invert on the return.
If there was silence now that's an indication the basic set up can be assumed to be all-right. If not and careful level adjustments still wouldn't make this occur that warrants a more detailed study as some cancellation should be possible in theory at least. Of course, double audio conversion doesn't happen in no time.

Next test would be similar but with the Big sky in the loop and with pass trough active, if available, or the mix wheel set to a 100% dry signal. I am assuming your normal set up in Big Sky is a 100% wet signal, correct?

You say you want to learn so maybe a good idea to try these and see what happens. Make some recordings too and label them properly.

You can also try different audio buffer settings to see if that changes what you hear regarding this effect or other external audio effects.

If this effect had phasing issues I couldn't live with and careful adjustments wouldn't yield an acceptable result, I'd contemplate making an exact copy of a source track and try to send that earlier to the effect send to see if that improved the sound.

I'm probably looking at scenarios like this soon as one of my main partners is going for a 100% analogue mix set up and I'm 100% in the box. It will probably be interesting.