Ableton Forum

Now really, this isn't very good at all.
I wish you would have got AAS to fix this persistent bug before the final release, I warned you about it ages and ages prior to the date.

REPRODUCE
1: Set tension pitch bend range to 12 semitones
2: play and hold a note, then bend it up (UGLINESS) and release the key
3: without releasing the pitch bend, play a new note (correct)
4: release

5: with nothing playing, bend the pitchbend all the way down
6: play a note and let the pitchbend rise back to the center position (UGLINESS)
7: play the note without pitchbend (correct)


ISSUES
in step 2, the note bent up, what the hell kind of an interval is that?
It seems like two and a bit semitones or something similarly un-musical

in Step 3, now that is 12 semitones

in step 6, oh Christ, what the hell is that?
this synth was not ready for a release, as anything done with it now will sound totally different if this ever gets fixed.


Do you want me to send you a set to illustrate this bug?
it seems like no-one at Ableton realises how bad this thing is.

historical Beta thread, bug present since Beta 13
http://www.ableton.com/forum/viewtopic. ... ht=tension

I asked AAS about this issue and they confirmed that it's a limitation of the physical model. The pitch can only be bent up by a certain amount above the initial pitch, so while pitching down always work the range of pitching up that's available is limited for notes that are already playing.

Hi Claes,
that's a strange one - because Karplus-Strong is certainly capable of pitchbending in both directions accurately.

here is an VST I just made to demonstrate the fact, a very simple Karplus-Strong synth.

http://www.plugins.timeshard.com/dev/an ... s-demo.dll

that's a windows VSTi, so I hope you have a windows machine nearby



notice the absurdly large pitch bend range dial
also notice that it bends perfectly in both directions

There is nothing special about this file, other than it was made in the SynthMaker IDE. It is just a Karplus Synth like many others. I would be surprised if I can manage a working pitchbend and the AAS team cannot.


oh, and one further issue with the AAS pitchbend :
it recovers very slowly. For example : if you pitchbend a held note down 12 semitones and then release and play a new note a short time later - the new note has pitch bend information applied, even though the bend envelope is back at 0 for quite some time.

I'll detail this further elsewhere - and provide files.

====


edit - link to "pitch bend recovery bug"

http://www.ableton.com/forum/viewtopic.php?p=627440

bump

The slow recovery has to be due to the parameter smoothing afaics.

I don't think it makes much sense to compare ss/tension with a Karplus-Strong implementation since they're quite different. I asked their programmer about it and although he didn't recall the exact details why it was bounded in this way (one of their acoustic gurus would be the one to ask), it definitely wasn't trivial to fix. But even Karplus-Strong has it's limitations as you can't bend lower than the delay-buffer used for the string allows, which amusingly enough is the total opposite of the AAS implementation.

Hi Claes,
That's a shame that Tension can't do pitch bending, I guess it was a mistake to include it in the GUI, as I downloaded the AAS StringStudio demo and I notice that their pitchbend parameter in that version is noted as "for downward bends only". Perhaps the Tension bend range should be labeled similarly.


Regarding slow PB recovery and parameter smoothing
no other synths respond in this broken way, even Electric can bend and recover every time . It would seem odd that only tension responds to parameter smoothing in this way. IE - 1 time in 4 it does not recover from a bend down nd plays an incorrect note following that bend .
So, I still think that this is an issue with Tension - as it is not present elsewhere.

BTW
I know this is not the same as parametric smoothing, but just to add some extra detail :
MidiEventThinning is set to 0 in my options.txt, if that makes any difference to you, although the demonstration pitchbend envelope was drawn in the GUI, so it's probably of no consequence



Backing off on the Tension
If this pitch bend up is not going to be fixed then I think I will have to abandon Tension and build my own for those circumstances.
Although I don't always need pitchbend, I will always have in the back of my mind that if I want to use it at some point - I will not be able to. A guitar that cant bend a string?

I guess Tension will still be usable for harpsichords and pianos and similar static instruments

I think I will call my version "Slackness"