Crackles in the rendered WAV

[sandbags]

Hi.

Last night I was making a track in Live (8.2.7, OSX 10.7.2) which I rendered out to a WAV file.

Puzzlingly the WAV file had some crackling in it. Yet, when I went back and replayed the section within Live, no crackling.

A friend I was talking to who knew I was using an audio recording suggested "DC Offset" to me. I had no idea what that was but, since I already had the utility plugin in my chain I ticked DC offset, re-rendered and... no crackles. Job done.

However I then go back and read about DC offset and find out that it's an artefact of A/D conversion. Now I'm confused because my recording came direct from Reaktor (i.e. saved a WAV using the Reaktor built-in recorder) so no A/D.

So I'm left with some questions:

1) Why did I get crackles in the rendered wav but not in Live?
2) Is there any way DC offset could be responsible? (I don't think so) Or was it coincidence that turning it on "fixed" the problem (my bet)?
3) Why does Live search for max amp & then render? Surely if there is anything random going on the maximum amplitude the first time around might not be the maximum the second, could this lead to clipping in some circumstances?

I'd be grateful for any wisdom you guys can impart to me.

Thanks

Matt

[Klauser]

Make sure your not clipping the master track. It's probably that.

[sandbags]

Make sure your not clipping the master track. It's probably that.

Thanks Klaus but I don't think so.

1. I had a limiter on the master out, set to avoid clipping
2. If I was clipping I should have heard it in Live when playing the track, not just in the rendered wav.

Matt

[Tarekith]

1) Why did I get crackles in the rendered wav but not in Live?

>>> Hard to say for sure, could be a lot of different things unfortunately. <<<

2) Is there any way DC offset could be responsible? (I don't think so) Or was it coincidence that turning it on "fixed" the problem (my bet)?

>>> I don't think this is DC offset. <<<

3) Why does Live search for max amp & then render? Surely if there is anything random going on the maximum amplitude the first time around might not be the maximum the second, could this lead to clipping in some circumstances?

>>> Because you have the normalize option turned on Live's Export options. As for the second part of your question, I'm not sure how Live handles it, so that's a really good question. If you have a limiter on the master anyway though, still a moot point. <<<

[chapelier fou]

-Maybe a vst causing the problem ?
-i'd suggest to create an audio track set to resampling and record the song in real time. Then see if the same problem happens with the recorded file. If not, at least, you'll have your export (except for the master limiting aspect, you should put it in this track, if it works)

[eflatt]

From what I have learned...clicks and crackles arise from clipping or buffer under runs. However Live is able to handle 64 bit internal processing so it can handle basically any word length.

The problem might lie in how the file was rendered. There are various options that are available when rendering, of which I am sure you know about. Probably you could re-check these settings, or at least play around in this area a little.

[llllll1111116]

Same problem here (8.2.8, OSX 10.6.8)

eflatt you were right

Playing with rewired reaper at "126 buffers" : OK
Rendering at "2056 buffers" : OK
Rendering at "126 buffers" : VSTs on Reaper CRACKING

Please, ableton team, can you fix that one day?

Thanks

[Buklen]

Trying turning up your buffer size before you export, I had a track that I rendered out at a high buffer size, but one of the effects didn't end in the right position so I rendered the track out at a lower buffer size and it was full of snap, crackle and pops from underuns, It's quite bizarre honestly, the process for exporting might be more primitive than i thought.

[Stromkraft]

There's something wrong with the premise of this problem as I've rendered crackle free tracks that couldn't even be played inside Live because of many VSTs in High quality mode and many plugins on a weak machine. I also know several others that have had the same experience.

[Stromkraft]

Hi.

Last night I was making a track in Live (8.2.7, OSX 10.7.2) which I rendered out to a WAV file.

Puzzlingly the WAV file had some crackling in it. Yet, when I went back and replayed the section within Live, no crackling.

A friend I was talking to who knew I was using an audio recording suggested "DC Offset" to me. I had no idea what that was but, since I already had the utility plugin in my chain I ticked DC offset, re-rendered and... no crackles. Job done.

However I then go back and read about DC offset and find out that it's an artefact of A/D conversion. Now I'm confused because my recording came direct from Reaktor (i.e. saved a WAV using the Reaktor built-in recorder) so no A/D.

So I'm left with some questions:

1) Why did I get crackles in the rendered wav but not in Live?
2) Is there any way DC offset could be responsible? (I don't think so) Or was it coincidence that turning it on "fixed" the problem (my bet)?
3) Why does Live search for max amp & then render? Surely if there is anything random going on the maximum amplitude the first time around might not be the maximum the second, could this lead to clipping in some circumstances?

I'd be grateful for any wisdom you guys can impart to me.

Thanks

Matt

Could you please try and isolate the problem by open the same project (a copy maybe) and reversing the DC offset? Then watch the CPU and disk usage while rendering. Also try turning off normalization which is just stupid to have IMHO if you are using a Limiter on the master.

[Tapestree]

(Necroing for people googling the problem)

I found my track was crackling because I had a redux in the master chain that i was occasionally clipping a tiny bit. Most effects have a whole bunch of headroom, but Redux inherently gets pretty nasty pretty instantly.

[BloodyNine]

I have the same issue: can't hear any crackle in Ableton (live 10 suit)
but when I export the wav file and open it in a new Mastering Project....snap crackle and pop

-changing sample rate doesn't make a difference
-i've frozen all tracks that are midi
-the volume on all tracks is no higher than -14db
-nothing is clipping anywhere
-no normalisation on export
-the click/crackle is on the exact same spot every time, I even tried rendering all the tracks to audio and then create fade in/out on the specific spot (except for one midi track that doesn't play during the moment where the crackle can be Heard)
-cpu is between 25-50%

Any suggestions much appreciated

[Codiferous]

What finally worked for me was turning buffer size all the way up and fading in my sends which included echo, delay, etc.

In my troubleshooting I noticed that I had no crackling when all of these sends were turned off.

I also noticed for some reason the start of one midi clip was creating another crack around 32 seconds, even though it wasn't audible prior to export. I dragged it in a slightly and that cured it. Seemed like it was some sort of export glitch exacerbated by delay, echo or reverb.

----------

So, issue maybe caused by echo, reverb, convolution reverb (max for live) or delay?

I was getting a mean crack right on the start of my exported track, as well as another one about 32 seconds in. Seems like it was some sort of recording glitch made worse by these audio effects. There was no cracking in live, only on the export. It is super clean, no clipping, no cracks on the actual track. Sounded like bliss in live, crackly on export.

I tried increasing buffer size, tweaking all export settings, restarting, exporting other songs, etc for about 2 hours. Some of which worked for a quick test export on small segments but then it came back when exporting the whole track.

It was a similar crack like what you get at the very end of an export on audio when it does that final bit depth/dither conversion, also made worse if you have on reverb, etc. But that one isn't baked into a track or recording. The one I was having on the exported track was.

What finally worked was turning buffer size all the way up and fading in my sends which included echo, delay, etc. I also noticed for some reason the start of one midi clip was creating another crack, even though it wasn't audible prior to export. I dragged it in a slightly and that cured it.

I've never had any cracking in Live 9 on export. I just upgraded to 10 and low and behold, my first export took about 2 hours because of this crackling issue. Yarrrr.