Re: [Audacity-devel] More about the Mixer Board

[Gale A. <ga...@au...>]

| From Vaughan Johnson <va...@au...> 
| Fri, 24 Jul 2009 15:03:50 -0700
| Subject: [Audacity-devel] More about the Mixer Board
> Again, moving this conversation to -devel.
> 
> Steve wrote:
> > What does the dB scale on the Mixer board refer to?
> >
> > Double clicking on the main slider I can enter a number, for example -12
> > which is the same as the -12dB reading on the track, but the slider on
> > the Mixer Board indicates around -26 !?
> 
> ... In short, they should not match. But visually, because they're the same 
> length, there is cognitive dissonance, an expectation that they should 
> match, and we've discussed this on -devel. I'm thinking of shortening 
> the meter and adding a control or two below it, to reduce the visual 
> association of the slider and meter being the same length.
> 
> The controls I'm thinking of are a checkbox for post-fade (on by 
> default) and maybe one for locking gain sliders per your suggestion, 
> pending comments on -devel.

+1 (I've already suggested the latter in the other thread Vaughan 
started in response to Steve). 
 
> I welcome comments on how to make this visually clearer. Definitely the 
> slider should be vertical and long (as on hardware mixers), but it's 
> narrow, so it's natural to put the meter next to it. I put the meter 
> ticks on the right to dissociate them somewhat, but a lot of users will 
> probably have the same confusion.

I still think the dissociation could be enhanced by some visual 
tweaking of the slider. You thought colouring would be 
difficult to implement cross-platform (my idea was that the 
slider section for positive gain could be a different colour). 
How about replicating the solid line that is underneath the 
slider ticks when it is aligned horizontally?  


> > However, during playback the meters show at the correct level.
> >
> > If I push the slider on the track up to +6dB, the Mixer Board slider
> > goes up to the top of the scale, and as I continue to increase the
> > slider on the track, the Meter Board slider is unable to increase any
> > further and so is at odds with the track slider.
> >   
> I think with the above information, you'll see this was a 
> misunderstanding of what's happening. They're different scales.

Yes but we still have the problem that the displayed gains of the 
Track Panel and Mixer Board sliders can be different in excess of
+6 dB. I think you were still toying with solutions to this.  

 
> > Would it not be better to have a second scale on the Mixer Board so that
> > the position of the slider could be seen in dB, and, although
> > unconventional, showed a scale of +36 to -36dB (the same as the track
> > slider).
> >   
> Maybe. I was using a derivative of the gain slider from TrackPanel, 
> which doesn't have those, but could be added. My concern is that it 
> would get too crowded, but I suppose I could increase the width. Again, 
> I welcome comments on how to make it clear.

I quite like that idea of a separate scale for the slider if no more
than five points on the scale. However, I think we'd agreed that 
higher resolution for negative gain was important, meaning we 
wanted to stick to a scale from -36 dB to + 6 dB?     


> > Another issue is that sometimes if I resize the Mixer Board, it will not
> > be redrawn correctly, the bottom of the board will flicker, and Audacity
> > will lock up.
> >   
> 
> I thought I had fixed all those issues, but if you can give me a 
> step-by-step to replicate it, I'll certainly look into it.

For me on Windows, with three tracks in MixerBoard, I cannot 
resize horizontally. Dragging the right edge rightwards, I would 
assume I would be able to resize. Dragging that edge leftwards, 
I see the flickering Steve mentions. 



Gale