Crackling sound from tension

[borg nagar]

I just upgraded to live 8 suite and I am trying out Tension for the first time.

What I'm getting is nasty crackling from low octave sounds and the flattened waveform from those parts looks like this:



So there's clearly something really wrong. I don't think an instrument should output such a wave in any case - even less if should be physical modeling.

Here are the basic settings, the crackles occur when playing D0/D1 notes.



That makes the instrument completely useless. Refund?

[Slacker4hire]

there's definitely something up with that waveform, but I don't believe it's because of tension.

I recreated the instrument settings with no errors here (at least in the 9 beta) playing both d0/d1 and others.

[borg nagar]

Thank you for trying it out Slacker4hire. I wonder where the problem could be... since I suppose flattening and everything I do here should happen inside Live with no VST effects or anything messing things up. (Windows 7, Ableton Live 8.3.4).

I made a test live pack if anyone wants to give it a try. Including one midi track of tension playing simple octave bass. Almost each note-on produces an audible click. Here it is:

https://dl.dropbox.com/u/848631/tensiontest.alp

And an example flattened waveform from this test with the same problems:

[tone61]

I tried your live set in 32bit 8.34 and can hear the crackles.

[borg nagar]

Thanks Tone61,

I have sent an official support request to Ableton. Let's see what happens.

[jsn]

Hi. You realise that you are triggering the notes in Mono play mode right? This could cause some "clicks" in the audio when notes are overlapped, as they are in your Live clip. I think you can resolve this by adjusting Tensions play mode and perhaps bring back the Decay of the string and maybe some of the Stiffness. As an experiment to see what I mean, go in and increase your (Polyphony) voices to 8 instead of Mono unision and you should discover the 'clicks' disappear.

[borg nagar]

You are right. If I increase the polyphony to higher polyphony I don't get crackles, but then I have to ask what's the purpose of Mono Mode then?

The reason I chose mono polyphony was to stop overlapping bass notes from existing. And after digging deeper into the synth, I guess I should've used an envelope to cut the notes and proclaim mono mode useless.

Thanks!

[jsn]

Hi. Tension is an Applied Acoustic Systems string synthesizer. I am not entirely sure it is organised internally signal-processingwise as your run-of-the-mill software synthesiser, therefore it may not be programmable in the conventional way. You may perhaps benefit from reading the manual to AAS String Studio VS-1, as this is AAS's own version of the Tension instrument (it would seem w/ perhaps a few additional features). I say this because I found a extra info in their manual for UA VA-1, which is their own incarnation of Ableton/AAS Analog synthesiser.

[borg nagar]

Here's what Ableton Support kindly answered to me:

Hi there,

Thanks for contacting Ableton Support.

I was able to open the project you sent and reproduce the issue you were experiencing here.

What happens could be described as a bug but is more likely expected behavior from this instrument.

I narrowed down the issue to the String settings of Tension. This section runs quite a complex physical algorithm to replicate the vibration in a string with parameters such as how long it vibrates, the amount of high frequency damping, etc.

In your case I found the clicks to always occur either when 2 notes overlapped or during a quick succession of notes.

There are two further points to note here. Since you have the voicing section set to monophonic, Tension is able to sound one note at a time. Secondly, the String Decay is also set to quite a high value in your project. This means each note stuck is sounded via the string algorithm and will last quite some time.

In cases where notes overlap or where the next note sounds before the previous one decays, the string algorithm is interrupted suddenly, causing a click.

The solution is to either increase the number of voices to 4 or more, or to adjust the String's Decay and the MIDI notes so that you don't begin a new note as the previous one is still sounding.

I hope this information helps!

As an aside, when investigating I came across this article which you might find interesting: http://www.abletonop.com/2012/07/workin ... excitator/

But. How is a phenomenon that is impossible in physical world "likely behaviour" of a physical modeling synthesizer?

[jsn]

Hello again. Well, I've not met one physically modeled synth that is a 'perfect' replica of natural instruments it aims to recreate. I suppose it is simply time for you to settle for a workaround You can get similar bass sounds from FM synthesis when you shape the envelopes just right. Most FM synths play well with multiple overlapping MIDI events, despite mono polyphony. I suppose you could write AAS a nice letter asking if they have some kind of workaround if you absolutely cannot settle with another solution. If it were me, and I MUST have this synth on the track, I would try a transient shaper with some EQ adjustment after that. A good transient shaper is not only about bring out transients, but burying them as well if the need should arise.

[borg nagar]

Hello again. Well, I've not met one physically modeled synth that is a 'perfect' replica of natural instruments it aims to recreate. I suppose it is simply time for you to settle for a workaround You can get similar bass sounds from FM synthesis when you shape the envelopes just right. Most FM synths play well with multiple overlapping MIDI events, despite mono polyphony. I suppose you could write AAS a nice letter asking if they have some kind of workaround if you absolutely cannot settle with another solution. If it were me, and I MUST have this synth on the track, I would try a transient shaper with some EQ adjustment after that. A good transient shaper is not only about bring out transients, but burying them as well if the need should arise.

Did you read anything from the thread above, even the post in which I replied to you? Because what your are saying is complete bollocks. Here's why.

I never wanted the synth to sound like a replica of a natural instrument (I mean who would think it would?), rather but report a bug, which is that the waveform should NEVER make that kind of one sample jumps if it is trying to emulate a natural phenomenon, nor it should do that in any case, with any synth, plugin or software. And like I already stated, which you failed to read, is that I already found a workaround - using an envelope instead of the buggy and useless polyphony setting to prevent more than one sound playing. And transient shapers?! Give me a break. First RTFM, now this...