Simpler/Sampler interpolate at native sample-rate?!

Timur · Post by **Timur** » Mon Dec 17, 2007 12:33 pm

During my other tests I noticed that both Simpler and Sampler work at "Normal" Interpolation by default. Unfortunately I also found out that they do change the sound even at native sample-rates?! That means that when I load a 44 kHz sample into a 44 kHz project then the sample still gets interpolated and thus modified from the original sample. For Sampler this is true for all Interpolation modes and actually "Good" Interpolation seems to be worst in this regard aka changing the original sample the most.

While Interpolation can be switched off in Sampler it cannot be switched at all in Simpler, but will always use "Normal". Is this by design or is this a bug? I wonder how this affects quality of Drum Sessions which uses instances Simpler as far as I know?!

hoffman2k · Post by **hoffman2k** » Mon Dec 17, 2007 12:45 pm

Could I get a compilation of the results of all your recent tests in a pdf please?
Next to Abletons fact sheets, it would be nice to have Timur's fact sheet

Nice find.
I guess Simpler operates only at default because there is no switch for selecting a mode in the GUI.
And there could be an argument for blocking features coming into Simpler because they are already in Sampler. But this isn't just a plain parameter, its a quality setting.

So + 1 for being able to control interpolation on Simpler.

Timur · Post by **Timur** » Mon Dec 17, 2007 12:54 pm

Hehe, maybe not a bad idea with the Facts Sheet, the Ableton one left me feeling a bit disappointed!

But first we need to find out what is a "feature" and what is a bug.

hoffman2k · Post by **hoffman2k** » Mon Dec 17, 2007 1:07 pm

Welcome to the world of being an obsessive Live tester

Bugs? Features? Statements?
A lesser man would have gone mad years ago

Timur · Post by **Timur** » Mon Dec 17, 2007 1:12 pm

These are mostly exercises for me to learn the instruments. I'm checking the pros and cons of my plugins against each other so that I know which one to use for which task and on the way I'm learning about their features and how to use them (I can do some nice sound-demolitions with Simpler now).

Also I want most performance and workflow affecting bugs in Live 7 to be fixed before I start working seriously with it. So I' digging deep into it right now so that I don't have to care later when I want to concentrate on the creative workflow.

hoffman2k · Post by **hoffman2k** » Mon Dec 17, 2007 1:45 pm

Timur wrote:Also I want most performance and workflow affecting bugs in Live 7 to be fixed before I start working seriously with it. So I' digging deep into it right now so that I don't have to care later when I want to concentrate on the creative workflow.

Yeah, I recognized that determination. I started doing that with Live 3 and haven't stopped ever since. One day we'll get there....

Amaury · Post by **Amaury** » Mon Dec 17, 2007 2:08 pm

Hi Timur,

Can you tell about the procedure you followed to come to that conclusion?

Regards,
Amaury

Timur · Post by **Timur** » Mon Dec 17, 2007 2:46 pm

I did cancellation tests with drum-samples (especially crashes) via Invert Utility with:

Simpler vs Audio track: no cancellation possible, sustain/release bleeds through.

Sampler vs Audio track:

- cancels completely with Interpolation turned off, sums to -infinity on Master peak-meter
- same results as Simpler with "Normal" Interpolation
- worst results with "Good" Interpolation, attack and sustain/release bleeds through
- "Best" Interpolation gives better results than "Good" (less attack), worse than "Normal", attacks and sustain/release bleed through

Simpler vs Sampler: cancels with Interpolation "Normal" set in Sampler, sums to -infinity on Master peak-meter

Simpler/Sampler were set to 0 dB level, Sustain 0 dB, attack 0.1 ms, Decay and Release don't matter since I used full note lengths, but set to minimum. Used loops of different lengths, Audio track was looped via Follow Action (using Warp at original tempo leads to same results), Fade off. Results are not only measureable but also audible.

Matthias · Post by **Matthias** » Mon Dec 17, 2007 4:08 pm

hi Timur,

Simpler uses the interpolation stated 'Normal' in Sampler, right. You can't switch that in Simpler, by design.

Sampler's 'Good' and 'High'-quality-interpolations do not mean they are 100% neutral even when there is actually no resampling needed. 'Good' comes with a phase shift of one sample so it should nearly cancel if you delay the output of the audio track by exactly one sample. 'Best' is a bandlimited interpolation that is never sample neutral but quite neutral in terms of hearing.

That normal interpolation did not cancel out completely may depend on the setup of the envelopes or maybe related to http://www.ableton.com/forum/viewtopic.php?t=76475

best wishes,
matthias

Timur · Post by **Timur** » Mon Dec 17, 2007 7:46 pm

Hey Matthias, thanks for your answers!

Matthias wrote:Simpler uses the interpolation stated 'Normal' in Sampler, right. You can't switch that in Simpler, by design.

That's fine with me, but only if "Normal" interpolation is neutral at native sample-rates. Else it should be possible to switch it off entirely or at least be made clear via help and manual that Simpler affects your sound.

Sampler's 'Good' and 'High'-quality-interpolations do not mean they are 100% neutral even when there is actually no resampling needed.

Good to know, unfortunately the manual tells us nothing about it! Actually it tells us about nothing at all.

Live Manual wrote:Interpolation (Interpol) - This is a global setting that determines the accuracy of transposed samples. Be aware that raising the quality level above "Normal" will place significant demands on your CPU.

'Good' comes with a phase shift of one sample so it should nearly cancel if you delay the output of the audio track by exactly one sample.

Why does Latency Compensation not handle this automatically?

'Best' is a bandlimited interpolation that is never sample neutral but quite neutral in terms of hearing.

Bandlimited to what extend/band?

That normal interpolation did not cancel out completely may depend on the setup of the envelopes or maybe related to http://www.ableton.com/forum/viewtopic.php?t=76475

There effectively was no Envelope and Sampler cancels without problems as soon as Interpolation is turned off, like already written.

Where do you see the connection to the thread you linked to? That thread talks about Impulse and switching Mode A and B. Did I miss something there that is connected to Simpler/Sampler?

Tarekith · Post by **Tarekith** » Mon Dec 17, 2007 8:33 pm

Timur,

You should collect the results and all the testing you've done on Ableton over the last few months in one place and have it online. Some of this is very interesting and super indepth, be a shame to have it all just get buried in the different threads here on the forums.

I'd be willing to host it all if you don't have the room.

Matthias · Post by **Matthias** » Mon Dec 17, 2007 9:08 pm

Timur wrote:
Sampler's 'Good' and 'High'-quality-interpolations do not mean they are 100% neutral even when there is actually no resampling needed.
Good to know, unfortunately the manual tells us nothing about it! Actually it tells us about nothing at all.

I'll forward that to documentation, thx for the tip.

Timur wrote:
Live Manual wrote:Interpolation (Interpol) - This is a global setting that determines the accuracy of transposed samples. Be aware that raising the quality level above "Normal" will place significant demands on your CPU.

'Good' comes with a phase shift of one sample so it should nearly cancel if you delay the output of the audio track by exactly one sample.
Why does Latency Compensation not handle this automatically?

This is a quite complicated task and we never saw the need for it.

Timur wrote:
'Best' is a bandlimited interpolation that is never sample neutral but quite neutral in terms of hearing.
Bandlimited to what extend/band?

About ~3.6 octaves when pitched up. For higher pitch the resampling filter looses steepness. When pitched down it stays always the same.

Timur wrote:
That normal interpolation did not cancel out completely may depend on the setup of the envelopes or maybe related to http://www.ableton.com/forum/viewtopic.php?t=76475
There effectively was no Envelope and Sampler cancels without problems as soon as Interpolation is turned off, like already written.

Where do you see the connection to the thread you linked to? That thread talks about Impulse and switching Mode A and B. Did I miss something there that is connected to Simpler/Sampler?

In there I talked about a bugfix for Impulse where it stretched even if it shouldn't. This is also true for S(a|i)mpler which then resamples even if it is not needed. This was due to rounding mode changes we did for L7. For S(a|i)mpler this effect should never be 'hearable' except when doing cancelation tests. On my machine using the latest builds, everyhing cancels with interpolation set to 'Normal'. So it will with the next bugfix release.

best wishes,
matthias

tricil · Post by **tricil** » Mon Dec 17, 2007 9:08 pm

Tarekith wrote:Timur,

You should collect the results and all the testing you've done on Ableton over the last few months in one place and have it online. Some of this is very interesting and super indepth, be a shame to have it all just get buried in the different threads here on the forums.

I'd be willing to host it all if you don't have the room.

+1

Timur · Post by **Timur** » Mon Dec 17, 2007 9:56 pm

Thanks for all the in-depth informations Matthias! <thumbs_up>

Good that these things are fixed with the next release. I really only stumbled upon it when I was checking some other issues and thought to better make an own thread out of it.

Considering the collection some guys are asking me about, I will consider it. I'll buy me some web-space quite soon anyway, so I should have space for that, thanks for the offer. But feel free to collect my posts yourself though, I'm not craving for the extra work. And hey, don't we have Fact Sheets, manuals and helpfiles for that?!

One problem with these collections is that with the next version your hints are old-news again, cause something changed already.

flowdesigner · Post by **flowdesigner** » Mon Nov 07, 2011 1:59 pm

Timur wrote:
While Interpolation can be switched off in Sampler it cannot be switched at all in Simpler, but will always use "Normal". Is this by design or is this a bug? I wonder how this affects quality of Drum Sessions which uses instances Simpler as far as I know?!

feature request !

Simpler/Sampler interpolate at native sample-rate?!

Simpler/Sampler interpolate at native sample-rate?!

Re: Simpler/Sampler interpolate at native sample-rate?!