Well, let's say I have something very global, a reverb bus for example, that I'm sending all kinds of stuff to. It's a (minor) headache to have to manage that. Let's say I'm using that reverb on, I dunno, both backing vocals and maybe keyboards. I want to bring up the backing vocals group at one point, but not the keyboards group. So I don't want to mess with the level of that reverb. See what I mean?
 
Like I say, it's not a big deal, and there are all kinds of architectures of a mix you could employ that wouldn't present that issue.

lfm

John T

lfm
My example of simple one fader doing a jump from 0dB to -8dB, and let's say a send at -12dB on that postfader - already create a change in dry/wet without we thinking so much about it.
  

 
I think I must be misunderstanding you, because on the face of it, this is simply wrong.
 
You bring down the dry signal of the original track. The send on the track is post-fader. Therefore, whatever reduction you applied to the track is also applied to the send, and the wet/dry ratio is preserved. Or do you mean something else?

I am saying that is the misconception I lived by until I started studying what VCA's are about.
 
Why is there an issue automating volume and not sends?
 
So you are saying that 0dB dry plus a -12dB wet give the same ratio as -8dB dry and -20dB wet?
0dB example
(1/1)+(1/22) = 1.046 result of dry+wet.
Ratio wet is 0.045/1.046=0.0434
 
-8dB example
(1/18)+(1/26)=0.094
Ratio wet is 0.0385/0.094=0.409
 
Please correct me if I did something wrong.
I believe it to be correct thinking - part of wet in the resulting mix dry+wet.
 

I don't think I understand those maths at all. Where are you getting the numbers from in the first place? 1/22, 1/18 etc?

To come back to this:
 

lfm
 
So you are saying that 0dB dry plus a -12dB wet give the same ratio as -8dB dry and -20dB wet?

Yes. That's exactly how the decibel system works. It's a relative scale, not an absolute one. ie: a change of 5dB is a change of a *factor* of 5 from the original signal. There is no decibel unit as such.

A Bell is the unit of measure. A decibel is one tenth of a Bell.
 
 

Well, sure but neither of them are an absolute amount, in the sense that lfm's maths seem to assume (again, I might have misunderstood, but that's how it looks to me).

lfm
Sending -12dB send on 0dB  fader, is not the same ratio dry/wet as doing -12dB on -8dB fader.
 

 
.......is based on a very diferent premise to:
 
[

lfm
So you are saying that 0dB dry plus a -12dB wet give the same ratio as -8dB dry and -20dB wet?

 
At least the concept of a post fader send is finally present in your numbers now Lars,  but it isn't great form to just redraw the lines of your argument without some acknowledgement of concession.
 
I still don't think your numbers are quite right though. If the post fade send was set to 0db and the fader was set to 0db, the 8db reduction would indeed be linear. Given that the post fade send is set to -12db to begin with, wouldn't the reduction in level on the post fade send be a percentage of the -8 db calculated by the ratio of the two initial values?
 
Pretty damned sure those post fade ratios are going to stay constant, given that that's their entire purpose.
As I said before there are a couple of slight advantages to 'VCA faders' in protools relating to automation. This just is not one of them.
 
 

No, it makes no sense to open your wallet if you know there's nothing in the updates you like or will use. That said, I know they will eventually have something I like. Although, it may be months after my renewal is up. I do like the current setup.

John T
Well, let's say I have something very global, a reverb bus for example, that I'm sending all kinds of stuff to. It's a (minor) headache to have to manage that. Let's say I'm using that reverb on, I dunno, both backing vocals and maybe keyboards. I want to bring up the backing vocals group at one point, but not the keyboards group. So I don't want to mess with the level of that reverb. See what I mean?

So if I understand correctly, it seems the two solutions as they stand with SONAR would be...
 

• Have the vocal reverb sends go to a bus (or aux track) that feeds the reverb rather than directly to the reverb itself. The vocal tracks themselves would go into a bus feeding the master. If you group the vocal reverb send bus and the vocal tracks bus, you could raise/lower the vocals and the vocal reverb sends, changes in one would track the other due to both following a ratiometric relationship, and you wouldn't have to touch anything on the reverb itself.
• Group the vocal track levels and the send levels as one group so they all track each other. 

 
Correct?
 
So...I assume the appeal of VCA control is that through some sort of magic mojo, you wouldn't need separate groups for the vocal tracks themselves and for the vocal reverb sends. Correct?

Yeah, that's basically it. It's a very slightly simpler way of doing something that can already be done.
 
Like I say, I'm not personally bothered about it. But I was trying to think of actual benefits of the feature, and that's the only thing I could really come up with.

John T
Yeah, that's basically it. It's a very slightly simpler way of doing something that can already be done.
 
Like I say, I'm not personally bothered about it. But I was trying to think of actual benefits of the feature, and that's the only thing I could really come up with.

Great, thanks for working through this with me. I was starting to think I was missing out on some game-changing feature because I just didn't see all this great value in it. Now I know why I don't