Summing Stack Fader and Post-Fader Send Level

According to my understanding, the fader of a summing stack shouldn't influence the post-fader send levels of the channels inside the stack/submix.

But strangely, sometime when I create a new project, the behavior of the summing stack fader is changed. It sometime works just like a VCA fader which can influence the send level of channels inside the stack. When it happens, I can't Solo the Aux channel with FX that those inside channel has sent to either.

This happens to both 10.4.7 and 10.5.0.

Is it a bug or there's setting somewhere that dictate how summing stack fader behave? From what I browsed in the forum, it seems like a bug. Just want to confirm.

Thanks in advance for your help!

I think that the summing stack's fader is irrelevant from the pre/post sends position of the channelstrips it encompasses.

The pre/post sends position are related only to the channelstrip they are located on. The summing stack (and its fader) is the output of its included channelstrip.

IOW, if a send is in pre-fader position, its channelstrip's fader will not affect the level of the send output. if it is set to post-fader position, then its channelstrip's fader will affect the level of the send output.

I think that the summing stack's fader is irrelevant from the pre/post sends position of the channelstrips it encompasses.

The pre/post sends position are related only to the channelstrip they are located on. The summing stack (and its fader) is the output of its included channelstrip.

IOW, if a send is in pre-fader position, its channelstrip's fader will not affect the level of the send output. if it is set to post-fader position, then its channelstrip's fader will affect the level of the send output.

I understand that Summing Stack fader shouldn't affect the send of inside channels at all, since it only controls the signal summed from inside channels.

But in some sessions it actually affect post-fader send, which is strange. That's why I emphasized Post-Fader in the topic.

I even have the Summing Stack fader behaved differently in the same session but on a different day.

That's why I asked the question. Is it a bug?

You would have to post a specific example of a Logic file exhibiting the issue so that one of us can have a look?

Please see the attached project.

When I first created the summing stack, I could solo the aux channel and hear the reverb only but now I can't.

Summing Stack Aux.zip

Yes you're right, I could verify the behavior you're describing, it seems to be a newly introduced bug . I remember someone else complaining about this not too long ago.

Thanks for checking it out David! I finally found out what happened.

When I first created the project, I made a folder stack for the 3 tracks and later flattened it. Even though the stack is flattened, the folder stack VCA fader remained active.

So after I made a new summing stack for those 3 tracks, I could solo the aux channel those tracks are sent to because that VCA fader is still in effect. When I deleted the VCA fader, summing stack changed its behavior back to default and the aux channel can no longer be solo'ed.

I recall that with earlier version of Logic, summing stack didn't behave like this in default. I guess the Logic programmers changed the summing stack function to allow its fader to influence the send levels but didn't take account of the possibility to solo the related aux channexls.

So now in order to solo the aux channel when a summing stack is applied, a VCA group that has to be created.