I’m quite sure this is covered somewhere but I can’t find the specific info. So sorry.
What’s the best practice for controlling volume of plugins in terms of mapping widgets? I’m running GP on a PC laptop. Using Arturia MK61 as top kybd and Yamaha CP4 as bottom kybd. One expression pedal for each kybd. I read somewhere not to map a widget to the volume control on the plugin itself. Just set it and leave it. So should I map a widget to a channel on a mixer block and how about the expression pedal? Should the pedal control a level in the mixer block or on the ouput block? Or some other configuration? I did my second gig this weekend using GP and VSTs, no sound from hardware (the CP4). I had difficulty controlling the mix between the different VSTs in my rackspaces.
Thanks! Dan
I would do so: use one channel of a (large enough) mixer block per plugin you use, map a Slider Widget to each to these channels and assign them eventually to the sliders of one of your keyboard controller to be able to do some quick adjustments easier.
Regarding your volume pedal you could gather all outputs of your mixer block in a 2 channels gain mixer at the output of everything and control its volume using you volume pedal assigned to a Slider Widget.
I would to the whole mixing stuff in the Global Rackspace and would route audio from Local to Global Rackspace. Hence you can change the way you mix easier without having to modify the Local Rackspaces.
Hope this helps 
What were exactly your difficulties?
When it came time to play a solo on the top keyboard, I would max out the expression pedal for that keyboard but I still didn’t have enough volume to cut through the mix. There are so many different ways to control the volume with gig performer.
There’s also something I don’t understand about the expression pedal. The pedal can bring the volume down to zero or max it out, but I don’t know how it’s doing that within gig performer because I haven’t mapped it to anything in gig performer. I put a MIDI monitor block after the input block and it showed MIDI control number 11 when I move the expression pedal. So I don’t know how that controls the volume. It’s not reflected in any block that I can see inside of gig performer. However, in the midi in block for the keyboard if I block expression events then the pedal is disabled and has no effect. So if I map the expression pedal to a gain and balance block at the end of the chain, how does that work with it also sending midi cc#11 messages? I’m confused. 
Sounds like the plugin your midi block is connected to, by default has the volume set to react to cc#11.
You could edit that inside the plugin, or block it in the midi block as you did and then map a widget to react to cc#11.
When you map any incoming control (such as your expression pedal) to a widget, the original MIDI event is deliberately blocked and so is no longer passed through the MIDI In plugin to your synth.
The idea is to not have to actually worry about MIDI events at all and do everything via widgets and host automation.
CC7 and CC11 MIDI messages respectively make it possible to adjust the volume and the expression of MIDI devices or plugin if they support these messages. Usually CC7 sets the maximum volume, while CC11 allows to change the volume within the range 0 and the max of the volume set by CC7. It is common practice to have a keyboard controller sending CC11 by default when connecting an expression pedal to it. If the MIDI in block of this controller let the CC11 go through to a plugin that support it, I will change the volume according to what was explained before.
If you adjust the volume of your plugin using GP Mixer plugins, you don’t need to care it the plugin you use supports or not CC7 or CC11 and you can even have you template ready for mixing any plugin. My advice would also be to block all MIDI messages other than Note On and Note Off, and explicitly allow what you are sure you need. I favorites of MIDI in block with this kind of settings. At a time I had the issue of a controller sending a CC7 0 (volume to 0), while I didn’t know it does it, resulting in a non audible plugin. This never happens any more when blocking all unnecessary MIDI messages.
Then, as suggested by @dhj, for many reasons, as the one cited above, it is much better in GP to control everything with host automation (parameters of the plugins you can map to GP Widgets). Hence you won’t have surprise of MIDI messages sent to plugins in your back and your settings will be stored through the Widget states.
Regarding your volume issues, use a GP mixer and try to work at a level around 6dB for each of you plugins and go to around 3dB if you need to cut through the mix for a solo. It is quite rare that I have to use an expression pedal while playing, I preferably use a variation with the proper level when I have to do a solo. The only time I really need it when playing live it is to a fade out in a song. But, of course it depends from what you are playing. If you are playing a B3 in a jazz trio, for sure you will need an expression pedal all the time.
Thanks for this info, it helps a lot!
I have set up a global RS with Omnisphere in it using it’s LIVE/multi mode. So I set up 4 different pno sounds (ac and epno) and mapped widgets and buttons on the Keylab61 to select the desired patch. So I use these patch options for the bottom kybd. (I always use some kind of pno sound on the bottom. I ‘show’ the GRS at all times so I can see which patch is active. So I have only 1 instance of Omnisphere in the GRS. It seems to work well.
I will set up the fader control of the mixer channels as you have suggested earlier, as well as the expression pedal now that I know how the MIDI CC11 works. Thanks for the help. Dan