paulnasca

sagetone · Post by **sagetone** » Sat May 14, 2011 10:18 pm

Hello Zyn experts. I've run into something a little strange with Zyn's envelopes that I don't fully understand. If you have a little time, please listen to this patch. It's in PADSynth, so there's only one envelope page.

http://dl.dropbox.com/u/14864402/Zyn_en ... 7-Pad4.xiz

And here is a jpg of the envelope page, and the amp and filter envelopes.

http://dl.dropbox.com/u/14864402/Zyn_en ... 0issue.jpg

I'm pretty sure I understand how to set ADSR's, but at the very end of this sound, it doesn't fade out, it drops out. In other words, with the way I have the ADSR's set, the amplitude should go from 100% down to 0% over the 3.4 sec setting. Instead, it seems to go from 100% down to, say, 10%, and then it just drops to 0%. The best way to hear this is to strike a key and release right away.

If you've got a good grasp of Zyn's envelopes, what am I getting wrong here?

By the way, I just tried reversing the D.dt and R.dt settings in the amp envelope, and that didn't make any difference.

Thank you,

Todd

sagetone · Post by **sagetone** » Fri May 20, 2011 12:47 am

Does anyone have a comment on this post? I'm very curious if there is something I'm not setting correctly or if this is the nature of Zyn-velopes.

Thank you.

folderol · Post by **folderol** » Sat May 21, 2011 7:33 am

Can't say I've noticed this in particular, but there are some oddities in the way Zyn's ADSR works. I've noticed that if you have an envelope that should decay to zero while a note is still being held, it doesn't in fact reach zero. The two might be related.

sagetone · Post by **sagetone** » Sat May 21, 2011 1:38 pm

Thanks folderol,

You have described what I am experiencing. So have you found any way to correct this? Or is this just a fact of life with Zyn as it currently stands, until there is a change to the specific section of code that processes these events?

fundamental · Post by **fundamental** » Wed May 25, 2011 4:31 pm

As far as I can recall, the envelope code never reaches zero.
I think PaulN said there was some sort of specific reason for this, but I cannot recall at the moment.
If this is to be altered, it could be fixed there or in the ad/sub/pad synth code (intelligently stop a note (would have good cpu savings (think sustain in poly mode))), though there be dragons in that code.

Goes to read the code now...

fundamental · Post by **fundamental** » Wed May 25, 2011 5:26 pm

Ok, magic number found.
In src/Params/EnvelopeParams.h you can find MIN_ENVELOPE_DB to be -40dB at the top of the file.
This leaves 1% of the full amplitude signal sitting around [10^(-40dB/20) -> 0.01].
In order to quiet things down I just pushed it to the extreme of -400dB (original signal times 1/100000000000000000000), which gets rid of any sound on my end.
Also Envelope.cpp:186 needs to have -40 changed to the MIN_ENVELOPE_DB.

sagetone, let me know if I solved your problem or just what folderol mentioned.

EDIT: just noticed that the discussed issue is with the windows version.
Its a good bit more difficult to recompile that than the linux version...

jackoo · Post by **jackoo** » Thu May 26, 2011 5:42 pm

Not that difficult. Could give it a try if ppl are interested.

sagetone · Post by **sagetone** » Fri May 27, 2011 12:42 am

Hi fundamental, thank you for your input. I somewhat follow what you are saying. However, I am not a programmer, and as you noted I'm running Windows, so I can't make changes to the code. It's pretty cool that you've thought through this though!

Hi jackoo, I'm def interested in this change if you could do it.

Thank you both.

paulnasca

KVR Audio

Zyn envelope issue