Post fader effects

We have already discussed to introduce Aux-Send effetcs, plugged in the effect chain and are hardwired to soundcard/Jack plugs.

We can do the same here, Introduce an effect that is hardwired to Master out, or probably better to left / center / right bus xFade input.
We can do it similar like the Aux decks (ore just reuse them?) to display VU-Meters and so on.

https://github.com/mixxxdj/mixxx/pull/919

I'd like to fix that. I also really miss this feature.
But I would rather modify the `Echo`-effect than the Reverb.

Thank you very much for adopting this!

How do you plan to implement this feature?
How will the GUI look like?

Do you need any help?

You can currently simulate this by cutting off the sound with a filter effect and putting other effects after it in the chain. This is fun to do by putting filter before echo.

> It also would allow us, for example, to cut the input of a reverb without muting its output, thus making a "freeze" effect.

Another way it is currently possible to do this is simply by stopping the deck (or letting it play to the end) without lowering the volume fader. Reverb and echo will continue outputting sound in this case.

It looks like this will require some refactoring of the core mixing engine. Currently it applies fader attenuation at the same time as it mixes channels together. These will need to be split into separate processes for post fader effects to work.

We currently have the chain dry/wet knob and the channel fader which both control the output of effects chains. This is redundant. I'm thinking that effects should always be post fader, so the fader controls the input and the dry/wet knob controls the output.

Food for thought:
http://www.skratchworx.com/school/s_and_r.php
https://www.youtube.com/watch?v=v3Vd0clpxyo

https://github.com/mixxxdj/mixxx/pull/1254

Thank you for the really nice an useful links.
It looks like Traktor has implemented the Rane solution from the Blog. This sounds reasonable.

Luckily I can actually already do this with the current Shade skin. B-)

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/7582