Why am I hearing phasing?

[Scott Maple]

I’ve jumped into Mixbus after 20 years of Pro Tools. I’m very impressed with the sound but have a few battles on my hands due to the new workflow.

I’ve set up a wee demo session to learn recording in Mixbus.

I have a stereo drum track bussed to bus 1.
The output of this bus is assigned to master out.
I’ve put a plugin on bus 1. Mixbus has set the latency (around 608 samples)

I am hearing phasing. If I manually change the latency I can ‘sweep’ through the phasing. This doesn’t make sense to me for two reasons.

1. I thought Mixbus’ default setting was for automatic delay compensation to avoid such issues.
2. As far as I’m aware there is only one signal chain for the drum bus. Therefore there is nothing for it to phase with?

Probably there is a straight-forward answer but I can’t figure it out.

Can anyone out there advise?

Thanks

Scott (noob).

[Dingo]

I have a stereo drum track bussed to bus 1.
The output of this bus is assigned to master out.
I’ve put a plugin on bus 1. Mixbus has set the latency (around 608 samples)

I am hearing phasing. If I manually change the latency I can ‘sweep’ through the phasing. This doesn’t make sense to me for two reasons.

1. I thought Mixbus’ default setting was for automatic delay compensation to avoid such issues.
2. As far as I’m aware there is only one signal chain for the drum bus. Therefore there is nothing for it to phase with?

Hi Scott and welcome to the Mixbus forum.
What you are describing is not normal. By default MB ships with Plugin compensation enabled, to check this go Preferences / Appearance / Toolbar and tick the 'Display Latency Compensation Info'.
This will then display the PDC factor in the toolbar. You can use this switch to turn PDC on or off.

What plugin are you using on Mixbus 1 ? Is there any chance it could be a mono only and hence one side only is getting compensated ?

Check by removing the plugin and replacing it with a known stereo plugin from another manufacturer just to check the path.

Also it should not make any difference (as PDC is across ALL paths from v6 onwards) but check if the Drum track is also going to the Master bus as well as MB1.

My suspicion is that there is something 'funky' happening with the plugin, but please post back and let us know. Perhaps a screenshot of your Mixer pane would help eagle eyes spot things.

Cheers and Happy mixing.

[Scott Maple]

Thanks Dingo

OK - fresh eyes revealed that I'd managed to send to both Mixbus 1 *and* Mixbus 8 (I had no intention of sending to MB 8, I must have been clumsy with my left-click at some point).

I disabled the MB 8 send and the phasing disappeared.

Still a bit confused though - as you wrote, due to PDC I wouldn't have expected sending to two MB's to do anything more than increase the volume?

PDC is engaged, I have made it visible in the toolbar.

[madmaxmiller]

Still a bit confused though - as you wrote, due to PDC I wouldn't have expected sending to two MB's to do anything more than increase the volume?

Yep that's correct. Could it be that the plugin itself moves phase internally? So it isn't detected by "external" compensation?
What happens when you put the master sends of the drum tracks on (together with the mixbus)? Phasing?
I'm sure the developers will be highly intersted.

Cheers,
MMM

[Scott Maple]

Good call, yes it is phasing when master send is on. It's not as obvious but it is there.

I've done some more testing and I'll try to summarise succinctly here:

1. If I put the same plugin on another bus and send to both busses, the phasing happens regardless. This suggests it is not plugin latency that is the issue as two instances of the same insert chain should cause equal latency.

2. It's *only* bus 1 that this is happening on.
If I send to e.g. bus 2 and 3, or 3 and 4 they are in sync. These busses have plugins on them, non-matching plugins, suggesting that PDC is working fine.

I tend to think 'user error' with these things. It's probably something which would be obvious to a seasoned user, but I can't see it.

[madmaxmiller]

I tend to think 'user error' with these things. It's probably something which would be obvious to a seasoned user, but I can't see it.

Just for fun, add another plugin of your choice to Bus1 (but no delay haha).
MMM

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I tend to think 'user error' with these things. It's probably something which would be obvious to a seasoned user, but I can't see it.

Just for fun, add another plugin of your choice to Bus1 (but no delay haha).
MMM

Oh and at the bottom of Bus1 - is there any polarity inverted?
MMM

[Scott Maple]

Problem solved, and yes it was in part me not thinking of the obvious test to fix.

I swapped out the plugin for another, and there was no latency. I returned the original plugin and there is...no latency!

In my first post I mentioned that MB had set the latency to 608 samples. Now it has a latency of 304 samples.

Does Mixbus' PDC ever get 'stuck' and need to be told to refresh the latency settings?

I can see that there's a 'reset' function within the plugin's edit plugin delay / compensation options but I must stress that I wasn't tinkering with any of that functionality until after I'd experienced the phasing.

Thanks for the help.

[Dingo]

@Scott Maple... just out of interest what was the plugin ?

[Scott Maple]

It's Brainworx Masterdesk.

It's a great plugin, just as well because Waves GUI is MIA - I hope that gets fixed!

[eyal]

Does Mixbus' PDC ever get 'stuck' and need to be told to refresh the latency settings?

It happened sometime, when it does bypass and un-bypass the plugin