Why can't I set the mixer fader to exactly what I want?

[darkecho]

I want the fader to be at +2.3 but it only goes to +2.4 or +2.2

 

why can't I set it to 2.3, even typing it in manually, it snaps to one of the two values, and I am not happy.

[ski]

Not a justification, but Logic has always had 128 steps of resolution for its mixer faders (127 plus "off"). This is a throwback to the maximum resolution provided for in the MIDI protocol for a single continuous controller such as CC#7, etc.

 

Considering the limited number of steps, a programming decision had to be made as to which level values would be represented -- and thus made available -- by 128 steps of resolution.

 

90 was apparently chosen to represent unity (0dB). That means that there are only 37 steps available to offer fader values between unity and +6dB, the max. throw of the fader on the upside.

 

On the flipside, there are 90 steps in which to define levels descending towards "off".

 

It's likely that there's a "table" (a list, basically) in the code where each of the 128 steps has a corresponding volume value. But of note is that the difference in value between steps is not consistent throughout the table. There are places where the steps are .1 dB apart, others where they're .2 dB apart, and I believe there are some that are .3 dB apart (check me on this).

 

So this is nothing new. It's a characteristic of Logic that's over a dozen or more years old.

 

Two exceptions:

 

1) a control surface, such as the Mackie control, provides much a greater amount of fader resolution -- probably exactly what you'd like to achieve. But it's not possible under normal circumstances to draw in automation nodes at any of the intermediate values you might like to get, i.e., exactly 2.3 dB

 

2) Logic's automation, as great as it is for the most part, is a bit whacky; sometimes when you're manually drawing in automation you can indeed achieve values that are "inbetween" those available from the GUI fader alone.

 

If you need über-fine control of level, use a Gain plug. Hold shift while moving the gain control with the mouse and you can adjust the level in .1 dB increments. And this control can be automated. BUT SEE THE POSTS BELOW FOR MORE DETAILS ON THIS.

 

[edited for clarity]

[maxedwards]

excellent bit of info ski, thanks...

[David Nahmani]

If you need über-fine control of level, use a Gain plug. Hold shift while moving the gain control with the mouse and you can adjust the level in .1 dB increments. And this control can be automated.

 

Never been successful automating the "Shift-dragging" of the Gain parameter in the gain plug-in. Upon reading back the automation, it doesn't read what I automated.

[ski]

Never been successful automating the "Shift-dragging" of the Gain parameter in the gain plug-in. Upon reading back the automation, it doesn't read what I automated.

 

David, I'll double-check that myself and post back with the results. BTW, when you say you've never been successful doing that, is that in L8 as well as previous versions of Logic? Or just L8?

[David Nahmani]

I'm talking about L8. I don't think I ever tried to do that in L7.

[ski]

I can confirm that in L7 it's possible to automate the gain plug's gain control in .1 dB increments (I tested moving the gain control down in .1 dB increments for 2 dB's worth of level change). Playback was accurate.

 

However, there are some GUI bugs related to this:

 

• When writing a value of -.1dB, the node generated in the automation display showed 0.0 dB. Writing a value of -.2dB resulted in a node showing a value of -.1dB. In other words, the value displayed for the automation nodes is .1dB hotter than shown on the Gain plug's GUI. Below, a screenshot showing this bug.

 

 

 

http://www.score2picture.com/logicpix/gainplugautobug1.jpg

 

Note that the SPL has already passed a node showing a value of -25.5 dB, yet the Gain plug shows a value of .1 dB hotter. The actual value I wrote at that node was indeed -25.4 dB, exactly what's shown on the Gain plug's GUI. So the bug is that the automation node values and the plug's values don't match.

 

• The automation event list isn't very helpful in displaying each node's value, as seen here:

 

http://www.score2picture.com/logicpix/gainplugautovalues.jpg

 

• Finally, if you were to click/hold/move a node for the purpose of changing it to a new value, it is impossible to move that node in .1dB increments. You can only move the values in increments of approximately .5 dB. I say "approximately" because the behavior isn't consistent. If you try it yourself you'll see what I mean.

 

But at least in L7 you're abe to automate the Gain plug in very fine increments. I'd be curious, David, to know if you get even remotely the same behavior in L8, and if not, what the differences are.

 

Best,

 

-=sKi=-

[David Nahmani]

In the automation event list, click the "001011" button (if my memory serves me right) to see the additional data where the extra information is contained.

 

Here is me slowly Shift-dragging UP on the Gain fader from -0.3 dB and up, and recording the automation. Upon playback the gain button moves up and down. L8.0.1

 

Funny thing is that -0.6 dB value creeping in again. Wonder if it's related to this bug - it's got to, right?

[ski]

Hi David,

 

My gut tells me that the "jumping" value behavior shown in your pic and in that other thread are related.

 

Clicking on the 001011 button does indeed show some additional data, but deciphering it is extremely difficult. I tried changing some values and things got really messed up.

[David Nahmani]

Clicking on the 001011 button does indeed show some additional data, but deciphering it is extremely difficult. I tried changing some values and things got really messed up.

 

Funny, in 8.0.1, disabling the "Additional Info" filter does not display any additional data.

[ski]

 

I'd say it's time to give Dr. L. a phone call, don't you?

[Anowrexiya]

In the automation event list, click the "001011" button (if my memory serves me right) to see the additional data where the extra information is contained.

 

Here is me slowly Shift-dragging UP on the Gain fader from -0.3 dB and up, and recording the automation. Upon playback the gain button moves up and down. L8.0.1

 

Funny thing is that -0.6 dB value creeping in again. Wonder if it's related to this bug - it's got to, right?

 

Did you try doing the automation with latch instead of touch?

[pantomimeHorse]

Am I missing something, here ?

-

Surely, if automation event quantisation is based on meta events, the

scale of dBFS for a mixer fader should be quantised into 65535 steps

across the logarithmic scale of dBFS, not 127 ?

-

Looking at those values in the automation event window screenshot,

it looks like it's kind of MIDI-based, with that value of 100 being about

right on a scale of 0-127 for the fader range ! !

-

Ok, tell me to go f*%@ off ..........

 

 

-

C

[shipjumper]

Someone at Apple needs to fix all of this.....

Somehow I'm thinking it will not be anytime soon though.

[MiserableSod]

I always switch the display to number, not dB. Much easier to work with.

[ski]

@ PHorse,

 

To the best of my knowledge, there are very few (if any) automatable parameters associated with Logic plugins (or channel strips) which, after they're recorded, will display more than 128 values for that parameter when viewed in the automation event editor. So if a plug that enables the user to adjust more than 128 values (such as the gain plug), you can only see 128 values in the editor regardless.

 

So the resolution of greater-than-128-step controls may be represented in the data structure of each Logic event, but we aren't allowed to see a resolution greater than 128 steps in the event editor.

 

The same is not true, however, for the automation displays. There the resolution shown can be much greater than 128 steps (the gain plug is a perfect example). But frustratingly it's not always possible to alter the values of these parameters from the arrange page's automation data display in the same fine increments as those shown. And as described above, the values shown for such data can sometimes be incorrect, despite the high resolution.

 

Finally, there aren't any Logic parameters that have 65535 steps of resolution, and even if there were, whether or not such resolution is scaled according to linear or logarithmic values is a matter of how those values are interpreted in software. You could have 32 values scaled so that they produce a logarithmic change in a parameter (even though the values at the top end of the scale would jump/step quite drastically).

 

Finally finally, with the current state of things, the event lists will only show you a parameter "throw" equivalent to 7 bits-worth of information (0-127, or 128 steps). If you were to "double" that by having an LSB and an MSB associated with those parameters (i.e., 14-bit), that's give you 128x128=16384 steps of resolution, and that's probably enough resolution for even the finest ears to be satisfied with. But Logic is still stuck in a 7-bit parameter value world. I wonder if that's the case with other DAWs? I do know, however, that when you use a control surface to adjust volume that the amount of resolution available from the hardware faders (as opposed to the software faders on Logic's GUI) inreases significantly.

 

@ Anowrexiya: touch and latch mode do not change the resolution of the parameter being written

 

@ MiserableSod: just a nipticky point --- setting level to display numbers is only applicable to the faders. Level changes as shown in automation displays will always show dB's tho.

[MiserableSod]

@ MiserableSod: just a nipticky point --- setting level to display numbers is only applicable to the faders. Level changes as shown in automation displays will always show dB's tho.

Rubbish

[ski]

Well, at least it isn't an exclamatory "rubbish!" I stand (or sit, as the case may be) corrected.

[inquiry]

(Just jumping in here having not read everything thoroughly...)

 

What's the resolution of pitchbend data in the Piano Roll editor -- that's supposed to be 14 bit since the original MIDI standard.

 

127-step resolution really is too low -- you can totally hear the notorious "zipper step" effect on filter sweeps, slow volume changes, etc.

 

I would guess Logic is doing some kind of smoothing as I don't hear this going on with softsynths...

 

----

 

Just tested and pitchbend appears with 128 steps in the Piano Roll but 16,383 steps in the List editor. I wonder what would happen if you did that thing to copy MIDI curves to track automation that David is always trying to get me to do : )

[ski]

At the risk of incurring another "rubbish" from Sod...

 

(Just jumping in here having not read everything thoroughly...)

 

What's the resolution of pitchbend data in the Piano Roll editor -- that's supposed to be 14 bit since the original MIDI standard.

 

The original resolution of MIDI pitcbhend was 14-bits, BUT very few controller keyboards to this day output actual 14-bit pitchbend where the MSB is set to something other than zero. So the MSB is "permanently" set at 0 (as seen in Logic) and the LSB is the value that changes.

 

127-step resolution really is too low -- you can totally hear the notorious "zipper step" effect on filter sweeps, slow volume changes, etc.

 

That has nothing to do with pitchbend. The zipper effect will be heard regardless of the controller used to modulate filter (per your example) if:

 

a) the controller (or pitchbend) data is 7-bit, and,

b) no smoothing is implemented

 

Still, some synths fare better than others at coping with 7-bit data and not producing an obvious zipper effect, even if no overt smoothing algorithm is in place.

 

I would guess Logic is doing some kind of smoothing as I don't hear this going on with softsynths...

 

On which parameters? And which parameters on which synths?

 

Just tested and pitchbend appears with 128 steps in the Piano Roll but 16,383 steps in the List editor.

 

There is no difference in the resolution of the actual data in either editor. It's just that the event editor (list editor) allows you to directly manipulate the MSB. But if the target synth isn't capable of dealing with 14-bit data, manipulating the MSB will have no audible effect.

[emperor12]

...so how do you guys even use Logic? If i wanted to do something basic like.....a filter sweep of white noise......you can TOTALLY hear the steps...its impossible to make it sound smooth? what would you guys do?

[fader8]

If i wanted to do something basic like.....a filter sweep of white noise......you can TOTALLY hear the steps...

That's an interesting statement, considering white noise is not periodic. What filter are you using that is creating audible steps?

[emperor12]

sorry that was just the quickest example i could think of...

 

sonalksis tbk filter on some white noise ...you can hear the steps

[fader8]

sonalksis tbk filter on some white noise ...you can hear the steps

That's not a good example as it has no smoothing. It's designed to be used as a MIDI controlled effect, ie it can be played with MIDI notes which control the cutoff frequency in semitones.

 

Try one of Logic's filters, like the EQ->Single Band->High or Low Pass. Those even have adjustable smoothing parameters. But even at 10mS smoothing, 12th order, I'm not hearing steps when I automate the cutoff of white noise.

[emperor12]

wow I learn something new everyday....for so long I have been going about it the wrong way.... thanks much!