Live's resampling quality aka Sample Rate Conversion

[thefool]

That said you do know i was here first right?

you were here first... so it's your thread? lol <--- not. fool I know you get into threads and just chat away, I'm not interested in that, Timur's brought up a discussion for adults, go play with your sister. if you have something of substance to post, I'm all for it, but I'm not up for your games on this one.

/pets head, slams face into cement. you're a weird one fool.

Timur please comment him.
And i did remove that comment as i saw it was stupid. I added another comment on why you always have to hit on me.

fine you get what you want. Now i can't even discuss stuff with Timur because you don't like me to?

[Tone Deft]

Timur please comment him.
And i did remove that comment as i saw it was stupid. I added another comment on why you always have to hit on me.

fine you get what you want. Now i can't even discuss stuff with Timur because you don't like me to?

'cause the thread gets all chatty with stuff like this (see how quickly that happened and I fell right into it), all that's missing is you PMing me a half dozen times. you can do anything you want fool, it's an unmoderated forum, have fun. I don't think you pick up on how annoying you can get, even when people say it out loud. nice guy, needs to chill. me, I'm just an asshole, once you embrace that you can do anything.

[thefool]

Timur please comment him.
And i did remove that comment as i saw it was stupid. I added another comment on why you always have to hit on me.

fine you get what you want. Now i can't even discuss stuff with Timur because you don't like me to?

'cause the thread gets all chatty with stuff like this (see how quickly that happened and I fell right into it), all that's missing is you PMing me a half dozen times. you can do anything you want fool, it's an unmoderated forum, have fun. I don't think you pick up on how annoying you can get, even when people say it out loud. nice guy, needs to chill. me, I'm just an asshole, once you embrace that you can do anything.

Yeah but i've had it for now.. If i can't even comment on topic stuff :/

gotta talk some stuff with a guy from the UAD forums. A NICE guy.

[Tone Deft]

OK Timur, put up or shut up time for me. lemme see if I can add to the confusion.

I grabbed this file it is not a music file, it is a LOUD swept sine wave turn down your monitors before playing it

http://www.cs.ucl.ac.uk/teaching/GZ05/s ... e-8Khz.wav
from this web page
http://www.cs.ucl.ac.uk/teaching/GZ05/samples/
a stupid simple 8kHz Fs, 8 bit file with easily identifiable sounds in it. distortion will be clear audibly, in plots and in Spectrum.

preferences-audio I/O sample rate is 44.1kHz because it's mathematically unfriendly to 8kHz. that won't change.

for all tests:
16 bits (doesn't really matter)
no dither in any of these tests
file type is wav.
convert to mono is on

Default SR & Pitch conversion set to Normal
drop the file in, render to 44100

repeat with SRC set to High Quality

listening to the results in Audacity with a default sample rate of 44.1k there are FAR fewer aberrations than in your initial test.
http://www.zshare.net/download/92071515fef539/ <--- audacity project file
check out the spectral content of the resampled files, the resamples aren't true to the originals but they don't sound bad. btw tracks 2 and 3, the test tracks, are already inverted in the project. they don't fully cancel with track 1 (1 at a time) but they do drop the original down a few dB (I don't know audacity well enough to read the meter in detail.)

dunno, that's my way overvalued $0.02.

[Timur]

Don't take it personal, but I think the quality of Live's Resample Engine (SRC) is sub-par in HI-Q and a POS in Normal mode.

First I'd like to apologize for calling Live's default/normal SRC a POS. This statement was based on too little evidence (my own usage case) and somewhat formed out of frustration because of having hit another wall in Live that I feel should not be there. If you check my past post you will recognize that I have not used such harsh words for Live's function before and I will try not to do it again.

Nevertheless I also want to underline that I asked you to not take it personal. That addressed both Ableton staff and those people on the forum who tend to push other forum members down personally whenever a technical discussion comes up.

So, the sample rate conversion adds some distortion to the signal. What a horror. A recording ends up with some more harmonics during the process. The end of the world.

Timur, i strongly advice you to never ever play back vinyl. Or use loudspeakers, or microphones, or human ears, or headphones, or any kind of tube equipment. Or transistorised amps. Or analog consoles, or listen to music with a car stereo. Or from an ipod. Or transfer to an mp3.

There is no need for sarcasm, Robert. I am well aware of the fact that about any sound-manipulation results in more or less audible distortion (adding of harmonies of different orders). But while some manipulation chains are expectedly doing that and are often even sought-after for that effect others, including SRC, are generally meant to be as transparent/neutral as possible. Last time I checked the quality of any SRC was solely judged on its ability to stay as true to the original signal as possible.

I bet if you would do a blind listening test with a bunch of people, most would prefer the same recording *with* distortion. And in case of vinyl they would call it "more natural","has better stereo image" and all that shit.

If the High Quality switch is on, Live uses an advanced sample-rate conversion algorithm that provides better sound quality at the expense of higher CPU load. Samples processed with the Hi-Q algorithm generate less distortion, particularly at high frequencies, when transposing a sample and/or matching an imported sample's sampling rate to the system's sampling rate. ... Note: In Live 7, the Hi-Q mode now uses an algorithm that produces even smaller audible artifact than in previous versions. We think it sounds great.

Would you please point me to the place in Live's documentation where it boast about SRC adding muscial distortion/harmonics and better stereo-image compared to the original clip? I wrote that before, if I want to alter a signal with musical distortion I chose Saturator or something in that department, not SRC (at least not unless I know about the special musical character of a SRC implementation).

Unfortunately you do not seem to have listened to the audio-files I provided, especially the default SRC had altered my original signal by such an extend that it's unuseable unless one is voluntarily seeking for this kind of sound-alteration. And the Hi-Q version makes the already unpleasing original even more harsh and noisy to my ears so that at least I have to doubt that I would chose it in a blind test. Anyway, this is not about blind-testing, but about staying as true to the original as possible.

Not every can afford that nifty PCM D-50 portable recorder you are adoring so much in the other thread, some people have to use their mobile phone/dictaphone for recording on-site. Those people will encounter problems when importing their recording into Live and I thought they should know about it and discuss some alternatives for SRC.

This discussion is so incredibly not to the point. As others said, if you think the SRC in Live is not good enough, there are alternatives. If everything else in Live is not good enough, there are also alternatives. The time you spent uploading all those graphs, doing all those tests, and so on... how much music could you have done at the same time ????

I am very glad that you adress that last point. Do you realize that you seem to be displaying feelings of being offended and effectively ask me (your customer) to stop using your product because it's supposedly not good enough for me? Your implication seems to be that my excessive demands cannot be fulfilled by reasonable means anyway, and so you are better off without me using your product. If you want me to stop sharing the experience I made when using Live with the community or Ableton support, or if you even want me to stop using your product (Live) then tell me straight, please. Like I said, no need for sarcasm.

You may even have a valid point here, but then again I ask you to check my past record of notes and complaints first. Generally I am asking nothing more from Live and Ableton than to properly provide the functions that have been advertised and documented. I cannot identify these expectations to be unreasonable or excessive on my side. On the contrary, I am even providing you (Ableton) and other users/customers with in-deep analysis (including audio/video/screenshots/graphs) to either help Ableton to solve the issues or helping other users to know about them and workaround them (if they don't want to make use of them voluntarily). Well, and yes, sometimes I even suggest changes or new functions.

As you already recognized this costs me alot of my precious time that I would prefer spending on making music without having to care for my tool's proper fuction (Live). But since Ableton's documentation of Live's inner workings and known issues is sometimes sparse to non-existant I am forced to analyze Live as part of my signal-chain myself like any engineer would do (eventhough I am hopefully still more of a musician than an engineer). After having done that work I like to share my results with the community and in case of unexpected behavior I contact Ableton's support in order to get help and fixing with my problems. Eventhough everyone at Ableton seem to be nice people the response to my support-calls leaves something to be desired. Like I wrote above, I'm hitting too many walls that should not be there and Ableton fails to remove them or at least put some signs up that warn against them.

[Timur]

Who what where (whatwhyhowwho?) uses an 8k sample rate????????????

who?

what for?

I still feel twinges of guilt for using "only" 44.1!

Some people cannot afford mobile recorders (or save their money for more important things). These people (including me) use their mobile phones/dictaphone for on-site recording. It's how modern life functions, the mobile phone becomes the center of both productive work and entertainment. So isn't it right for modern music to kind of reflect on that by making (ab)use of the very same tools that dictate our everyday life?

[Timur]

Well, the problem is, it confuses people. It's a bit like those is-my-penis-large-enough thoughts. I don't know how often I had discussions with inexperienced producers who where scared like hell that they a) use the wrong tools b) that their tools are not pro and all that. And for the rest it is also pseudo information. If a soundfile sounds like shit because it is warped, this is a different story. But harmonics -60dB added to a recording ???

Thorough documentation can take away that fear. I'm talking about documentation of audio-tools, not my penis, I can deal with that without documentation hopefully. I don't need to hold gear-size comparisons neither, as my my love for music and creation of my own auditoral childs do not (solely) depend on them. I mean, hey, I'm using an 8 KHz mobile phone recorder!

If the harmonics are in a complete different spectral range, it will be easy to filter them out. If they are close to the original signal they are inaudible.

In order to filter them out you need to know about them in the first place. Nothing in Live's documentation (or anything on the board that I've happened to come across) told me about the added energy in the high frequency spectrum. I had to find out myself in order to make educated decisions. And I chose to share my results with other users and ask them for input and discussion.

I mean, it is so easy to try this out. Take a recording, play it back at 0dB and add a variety of test signals at -60dB.

I do have to admit that I am not sure abot the -60 dB statement. I did not find time yet, but I will try to see by how much an added -60 dB signal affects the signal-chain once RMS compression and multi-band compression come into play. But this brings us back to the point of your first post, it will cost me valuable time that would better have been spend on making music in the first place. But since you/Ableton fail to offer me such data, but instead ask me to conduct such tests on my own, what can I do?

( And before this ends in total madness: Even the bad bad Live SRC will not add harmonics of that amplitude. The artefacts are much lower )

Did you listen to the audio-files that I provided? Use your own ears and compare the results of Live's SRC. I think that one can hardly claim the artifact to be inaudible (especially in the case of Live's default SRC). I listened to the original clip at original 8 KHz through my Audiophile 24/96 (it's able to play downto 8 KHz) and the X-Fi files was provided as reference because stays truest to the original signal.

It's all about reference. Timur, check conversions in logic, protools or bias peak and compare.
Warp should be off btw. If the same-ish distortions are present then......

Unfortunately I am not able to do that. But I did check with the tools I had at hand (X-Fi, AudioBurst FX). Both of these came even close to the results of Live's default SRC and according to my ears they do not exhibit the distortion of Live's Hi-Q SRC neither. The very reason why I conducted the spectrum-analysis tests with visual graphs was that I wanted to find out if the differences can be measured after I heard them. And very obviously they can.

[Timur]

@Tonedeft:

Thanks for providing us with your own test-results. Like I wrote myself before with different material the results of Live's SRC are far less audibly different, albeit even by ears I can still identify the default/normal SRC from the original/Hi-Q. Nevertheless my original problem remains, I do have recorded original material that cannot be imported into Live without sound-alteration/deterioration. Now that I know about that and experienced Ableton's response as represented by Robert I will look for workarounds/alternative SRCs unless I voluntarily want to make use of Live's characteristic sound.

Timur please comment him.
And i did remove that comment as i saw it was stupid. I added another comment on why you always have to hit on me.

I despise people picking on others and trying to hit them personally only because they don't agree with them on technical discussions. For some reason an intelligent and well-educated professional (like he claims to be) like Tonedeft and others in this forum feel like going rampage on other forum-members sometimes. I had been subject to the rudeness and expressed disdain of my seemingly missing technical background knowledge in this and other threads myself. But I'm an adult person with an ego that fits his shoes quite well, I'm neither bursting them nor can I hardly fill them up. So even when I'm admittedly striving for approval and recognition (attributes that define many artist) I'm strong and aware of my strengths and weaknesses enough for dealing with critics and disapproval.

Thefool, try not to take any personal attacks on you too serious when posting in forums like these. Most of them anonymous alpha-male members wouldn't dare to tell you the same things right into your face if you stood strong and proud in front of them in person. For some sad reasons communication over the Internet often leads to people acting disrespectful and intollerant, quite the opposite of what communication should be about.

[Timur]

Timur we cannot have this discussion if you cannot draw a line on what's acceptable noise and what' not acceptable. you've got the tools but you're not using them right. nearly every DSP algorithm is going to introduce errors, you've found a way to see them but you don't know how to interpret the results. that begins with establishing a baseline of anything below -XdB is 'in the noise' (where do you think that phrase came from? maybe they don't say that in Germany "don't worry about that, it's in the noise".)

You are right in that I cannot draw a line as in technical specs and dB, but I can draw a line as in "if I can hear artifact that disturb me then it's too much". Sorry for being so inscientific here.

test files can be short 3 seconds long. your test is cool and totally fucked for the reason that you're using utter crap as a test source. creative plus 2 lossy formats (yes you know lossy formats, I was just trying to follow your long ass description of what you did.)

Again you seem to be missing some point here. Forget about the Creative and the lossy formats! Again, forget about the Creative and the lossy formats! The AMR is the original sources, as crappy as it may be, it's my original and because it's crappy already I don't want it to deteriorate even more. The Creative sample was meant as a reference for a high quality SRC that does work well to my ears when compared to the original 8 KHz sample over my 8 KHz capable Audiophile.

And cutting 3 second long example of the original 8 KHz file needs a tool for doing audio-editing without SRC. Guess what, that was my original intend when importing the files into Live, I wanted to cut, edit and process them. Then I noticed that Live is not able to handle 8 KHz files without SRC (eventhough the Audiophile offers 8 KHz, Live only offers sample-rates as low as 22 KHz), then I noticed audible sound-deterioration, then I started this whole thread, and then I got annoyed again for wasting so much time on something as simple as importing a recorded audio-file.

Upsampling from 8 KHz to 48 KHz seems like an easy task, simplified math = x6, but I know upsampling is not that simple. It's very similiar to what algorithm to use for resampling images, bilinear? bicubic? lancosz? But while many/most graphic-applications offer several different methods to optain the best results for different scenarios most audio-applications do not. Quite a pity.

I think you're on to something but you don't know how to interpret your own results, you're jumping to extreme conclusions.

I did apologize for calling Live's default SRC a POS, I was wrong to do so. But beside the harsh choice of words, which "extreme" conclusions can you blame me for? The only conclusion that I came up with was, I put some original file into Live's SRC and the audible outcome is vastly different with the default SRC and audibly distorted with Hi-Q SRC. Any further conclusions were put up to debate so that other, more experienced users, can help me get around with this and even other, less experienced users, get an idea of the problem before driving into that wall themself.

thank you for your bug testing, we are all better off for it.

Thanks for the appreciation! At least I am not better off with it, because it leads to no results when you are only able to find something is broken without means to fix it. When the water-flow coming out of my bath' armature drops out I can call the plumber. Whome do I call when the audio-flow drops out in Live? Ableton support, I guess. But what do you do if all your plumber does is telling you "I will have a look at it" and then nothing happens for several months and the plumber doesn't even seem to show up?

[b0unce]

/headbutt Tumor

[Timur]

/headbutt Tumor

Oh, c'mon, b0unce. Don't bore me please! You're supposed to be a creative, so be a bit more creative. Make a nice shape of your sh*tpile, make it look like John Travolta or something, not just a pile of sh*t. <- See that's creative, don't take it serious though, it's only a bit of art and alot of entertainment.

[Tarekith]

Man, all you do is come here and point out how Live fails you as a tool, how it's inferior and how the staff doesn't live up to your expectations. If you're this unhappy that for months now the only things you post are detailed tests about how Live is in your mind inferior, then it's simple.

Don't use it, look for a different app.

It would be one thing if you were prolific with the app and still using it daily to write music and this stuff was seriously holding you up. But it's not. you haven't posted any music you've made with it since being here. This is all academic for you, and you alone. You claim you're doing a service to this community by bringing these things to light. Fact is, the community at large doesn't care one wit about the stuff you're posting, they're too busy using live to WRITE MUSIC.

The digital processes behind an app do not need to be 100% transparent for that app to be a valid music tool, proven time and again historically. I understand you want to make Live be better app, but at some point you have just stop and realize it is what it is, and not anymore. And none of these faults are at all keeping people from making incredible sounding music.

As for the Ableton's not getting back to you with detailed documentation, well duh, you're the only one that wants it. Why would they spend the time to create all that in order to appease someone who's not even using their product to create and release music with yet?

Seriously man, chill on the OCD and realize that Live is just NOT the tool you want it to be, and that most likely it never will be. Move on, make some music, stop listening for mosquito farts.

[dj superflat]

amen. seriously timur, you need to stop being defensive and think about the wisdom of what tarekith just wrote. i know you feel you're being unjustly persecuted for speaking truth to power, but there are many, many people who in good faith think you're really just being a crank. try to see it from their perspective. you may not agree, but at least consider whether you're somewhat to blame here.

[Tone Deft]

rule of thumb in life:

If you can't explain it simply, you don't understand it well enough

which has ALWAYS been my problem with your posts Timur. thanks for your pretty level headed disposition but something's gotta change, this ain't working.

TL;DR

btw - total number of downloads for MY test files - ZERO. nobody gives a shit, this is lame. 8k cell phone recordings... <rolls eyes out of head, onto floor>

[Timur]

I understand.