Bug, Fixed: Scene switching - bypass/mute/unmute problems

ales.prochazka

ales.prochazka

Member
Hi @FractalAudio.

FW 16.05.
Bug is confirmed by tests (see https://forum.fractalaudio.com/thre...rameters-blocks-switching.176815/post-2149699 ).

I probably found potential bug or space for improvement:
It looks, that when scenes are changed, first are changed setup of block parameters and then bypass of blocks. It causes some small issue in my preset. I have 2 scenes, where scene 1 is clean guitar with Delay ON and scene 2 is distorted guitar (different Amp) with delay bypassed (Bypass mode - Mute FX in). I want to hear tail of delay from clean guitar from scene 1, when my scene 2 is activated. But unfortunately, few miliseconds of distorted sound from scene 2 is sent to delay of scene 1 before it's bypassed.
My proposal is, when scenes are changed, first apply bypass mode on all blocks and then change parameters of block. It would solve my problem.
If it's necessary, I can provide sound clip of problematic part.

Thank you,
Ales.
 
Last edited:
Here is preset (attached).
It's switch between Scene2 -> Scene3 for 2nd chain (Input2->... -> Output2)

CPU is 70 %.

Here is also audio:


Problematic part is around 14 sec of clip.

Thanks.
 

Attachments

  • EUPHORY Track 3.syx
    48.2 KB · Views: 2
ales.prochazka said:
Here is preset (attached).
It's switch between Scene2 -> Scene3 for 2nd chain (Input2->... -> Output2)

CPU is 70 %.

Here is also audio:


Problematic part is around 14 sec of clip.

Thanks.
Click to expand...

hmm, i hear the clean sound being delayed when you change to the dirt scene.

is the Delay channel changing when you change Scenes?
 
Because I'm using for scene switch MIDI CC commands sent from my DAW, I solved it on my side by adding extra bypass MIDI CC command for problematic delay block before Scene switch Midi CC command.
But it's only temporary solution !!!

I'd like to see this bypass behaviour fixed inside Axe FX III.
Maybe algorithm for scene switching could be something like this:
  1. When "scene switch command" occurs, do:
    1. Set Bypass On (bypassed) in all blocks, which have Bypass Off in old scene and Bypass On in new scene.
    2. Change channels in all blocks, which have different channel in old scene, than in new scene.
    3. Set Bypass Off (engaged) in all blocks, which have Bypass On in old scene and Bypass Off in new scene.
 
It's definitelly BUG in scene switching !!!
I did some tests with sine wave generator and very simple preset. My findings are:
  1. When any Amp Block is changing channel during scene switch, it takes cca 53ms for chanel switch, but it also turn off all other blocks, which also change channel for the same time, even those blocks are not on the same signal flow.
  2. When bypass is done on other block in the same scene switch, this bypass is engaged after channel switch of Amp.
I attached 2 audio files, where it's possible to hear the problem and also attached test preset.




And here is sound clip, where Amp is bypassed(muted) and delay is enabled in 1st scene, and Amp is switched to another channel and delay is bypassed (Mute in) in 2nd scene.


Please, @FractalAudio, take a look on it ...

Thanks,
Ales.
 

Attachments

  • Test Scene Switch.syx
    48.2 KB · Views: 2
Last edited:
This is normal behavior. PEQ blocks mute during channel changes. If they didn't you could get a pop when switching channels.
 
FractalAudio said:
This is normal behavior. PEQ blocks mute during channel changes. If they didn't you could get a pop when switching channels.
Click to expand...

Maybe let me explain deeper, where I see the problem. I mixed here 2 independent problems unfortunatelly so I'll try to split them (please, read carefully, I'm not native English speaker...):

1. Problem: PEQ block mute time in combination with AMP block channel change ....

PEQ block mutes time during channel changes. Problem is time of mute. I did some measurement:
When only PEQ block changes channel, it mutes for 3 ms. But: when in the same "scene change" PEQ block changes channel and also AMP block changes channel, PEQ block mutes for exact same time as AMP block (53 ms), even it is on different signal flow (PEQ is between In2 -> Out2 and AMP is between In1->Out1). I'd expect, that AMP block would mute for 53ms and PEQ only for 3ms !!!. Implemented behaviour causes significant sound gap in signal, where is nothing changed only PEQ block channel. (see attached picture).

2. Problem: Order of bypass engagement during scene switch ...

When BYPASS ON is engaged and AMP block chanell change occurs during scene switch, first is changed channel in AMP block and then is turned BYPASS ON (e.g. on Delay block). It causes short artefact of new AMP sound in tail of BYPASSED ON Delay sound. Please listen example below.

Behaviour should be:
  1. Set Bypass On (bypassed) in all blocks, which have Bypass Off in old scene and Bypass On in new scene.
  2. Change channels in all blocks, which have different channel in old scene, than in new scene.
  3. Set Bypass Off (engaged) in all blocks, which have Bypass On in old scene and Bypass Off in new scene.


Here is picture for better explanation (attached).
AmpProblem.png

Thank you. I don't want to iritate you, I just want to have better product :)
 
1. All blocks that require muting are muted during a scene change until the scene change is finished.

2. I don't understand. Your English is too hard to understand. Please provide an example preset with instructions on what to do to demonstrate the problem.
 
FractalAudio said:
1. All blocks that require muting are muted during a scene change until the scene change is finished.
Click to expand...
That's a pity. We are using Axe FX III for 2 guitars in one unit and it's very obvious to hear gap in 1st guitar signal flow, where nothing is changed just Equalizer when in the same time 2nd guitar is changing sound of Amp.

FractalAudio said:
2. I don't understand. Your English is too hard to understand. Please provide an example preset with instructions on what to do to demonstrate the problem.
Click to expand...
Example preset attached.
Steps to reproduce:
  1. Select Scene 1.
  2. Play long tone. Delay is working fine, clean guitar Amp channel A delayed in left speaker.
  3. Still keeping playing tone, do switch to Scene 2.
  4. Stop play immediately. In left speaker you can hear also short fragment of sound from Amp channel B is Delayed. It shouldn't be there.
More obvious :
  1. Select Scene 3.
  2. Play long tone. Nothing is in output, due to Amp channel A is bypassed.
  3. Still keeping playing tone, do switch to Scene 4.
  4. Stop play immediately. In left speaker you can hear only short fragment of sound from Amp channel B is Delayed. It shouldn't be there. Nothing should be delayed in this case.
Hope it's clearer now.
 

Attachments

  • Test Scene Switch Bug.syx
    48.2 KB · Views: 1
You must log in or register to reply here.
Back
Top Bottom