Pops and clicks in playback during editing

[Dr. Killjoy]

I use Audacity 2.05 on Ubuntu Studio 14.04.
After a while of editing (that could be somewhere between 5 or 10 minutes after starting, forementioned problem occurs.

I attempted to record the sounds that I hear, but I could only by using my external recording device. (There seems to be no other sound recording program on Ubuntu that doesn't use Jack)
https://soundcloud.com/muziektaal/crack ... Bas#t=0:10

You can still hear the cracks though, that have an electrical feel to it. Really annoying during the editing process. This doesn't always occur, by the way. I tried to edit with one earlid of my headphones off. After a while, some loud beeps are also present. And after like 20 minutes of click and beeps, all is silent again.

What can it be? I tried every option for "Input device", checked the volume control for wrong settings, but I could not figure it out.

Is there any log that I can see through what happens? What to check?

EDIT #1:
There is a similarity with the topic "Static during playback": http://forum.audacityteam.org/viewtopic ... 48&t=79793 (I just didn't know how to call the sounds)

This what my audio device looks like:
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler HDMI Audio
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01)

Kernel information:
Linux
[*] 3.13.0-35-lowlatency #62-Ubuntu SMP PREEMPT
[*] x86_64 x86_64 x86_64 GNU/Linux

Processor:
AMD E2-1800 APU with Radeon(tm) HD Graphics

[Dr. Killjoy]

I've tried to work on another file. It seems that I don't get to hear the static cracks now.
Since it has been quite a while that I heard them, I can try to think loudly what might have caused this.

Both projects are interviews (length about 1-2,5 hours). Long, anyway.

The project that brings the static cracks, is an interview that I recorded using my Zoom H4N, the Zoom device encoded it directly to MP3.
The audio was imported in Audacity afterwards. I noticed a disbalance on the interview track and the songs I recorded on location. I tried to fix it first by running the standard compressor plugin. Afterwards I cut / seperated the interview parts from the songs, and put the music on different tracks. Then, I converted the stereo interview track completely to mono, including the blank spaces in between. As far as I can remember the cracks started occuring from then on.

The other project file contains only spoken word, directly recorded with Audacity on my ASUS laptop using an external analog audio mixer, using the microphone plug. For now, I will continue to edit this interview, I'll get back if I might encounter the cracks here aswell.

So what could've happened when I converted from stereo to mono? Is that conversion the cause of all this?

[kozikowski]

USB Audio Devices don't much like going through USB hubs with other equipment. That's a sure way to cause noise problems.

Koz

[kozikowski]

using an external analog audio mixer, using the microphone plug.

That's another way to cause problems. Mixer connections are robust, powerful and stereo. Mic-In is usually delicate, sensitive and mono.

http://www.kozco.com/tech/audacity/pix/ ... Lenovo.jpg

That's a Behringer UCA202.

Koz

[Dr. Killjoy]

EDIT #1:
I've been editing this project that was recorded using my old Behringer Xenyx mixer for over an hour now, and all went pretty smooth.
So far it seems it was the project with the imported MP3's that caused the trouble. What doubles it, is that I've been recording audio both using USB-mixers (and my Zoom on USB) and this old Behringer one successfully without having these 'cracks' / 'statics' on playback

So it is still only the project that I worked on previously, the one I uploaded the recording of.
My guess is still that something must've gone wrong when I converted some of the original stereo mp3-audio (that had been succesfully loaded into the Audacity project) to mono. Any ideas what that might have been?

[Gale Andrews]

I moved this to a new topic. You do not have the same machine as the other person whose topic you joined, and that topic turned out to be a playback issue on the computer.

I use Audacity 2.05 on Ubuntu Studio 14.04.

You mean "2.0.5".

After a while of editing (that could be somewhere between 5 or 10 minutes after starting, forementioned problem occurs.

I attempted to record the sounds that I hear, but I could only by using my external recording device. (There seems to be no other sound recording program on Ubuntu that doesn't use Jack)

The best way to record computer playback on Ubuntu is usually to use Pulse Audio Volume Control. See Tutorial - Recording Computer Playback on Linux - Audacity Manual .

I noticed a disbalance on the interview track and the songs I recorded on location. I tried to fix it first by running the standard compressor plugin. Afterwards I cut / seperated the interview parts from the songs, and put the music on different tracks. Then, I converted the stereo interview track completely to mono, including the blank spaces in between. As far as I can remember the cracks started occuring from then on.

So far it seems it was the project with the imported MP3's that caused the trouble.

See Why do I hear clicks when I remove or paste audio, or at the start or end of the track? for good editing practices like cutting on zero crossing points.

As stated there, the imported files may possibly have been recorded with DC offset . This may cause clicks when you edit. After importing files from the same source, use Effect > Normalize... with DC offset removal enabled before starting editing.

Record with Zoom to WAV if you can. MP3 is lossy. Audacity will decompress the MP3 to PCM when you edit it, so you are not saving disk space on the computer.


Gale

[Dr. Killjoy]

Dear Gale,

Thanks for your explanation. I must admit that I'm working with Audacity for over three years now, and that I understand the basic principles of editing interviews and making manual edits of songs. So to say, I am sure these "static pops and beeps" have nothing to do with that.

As I mentioned before in this thread, this problem occured after merging one stereo track to one mono track. After merging (and, by the way, removing some background noise) I both compressed (and normalised) the audio.

Of course, as you mentioned I tried to normalise the audio again (and remove DC offset), but unfortunately the static popping sound still occurs.

You seem like an experienced forum user, do you or anyone else recognise these static pops?
Here's the link again for an impression: https://soundcloud.com/muziektaal/crack ... n-audicity

[Dr. Killjoy]

I tried another option I thought of earlier: exporting all the audio, and then importing it into a new project. That fixed the problem of the cracks, but now, of course I have only one track left and I need to make the cuts all over again.

Fact is, in some way an Audacity project can go corrupt. I still wonder what caused this, so perhaps it can be fixed in the future. For now, I stick to my hypothesis. If anyone wants my project for debugging or study purposes, I am happy to share it. Any way I can help the Audacity team developing, I would be happy doing so.

[Gale Andrews]

I tried another option I thought of earlier: exporting all the audio, and then importing it into a new project. That fixed the problem of the cracks, but now, of course I have only one track left and I need to make the cuts all over again.

Fact is, in some way an Audacity project can go corrupt. I still wonder what caused this, so perhaps it can be fixed in the future. For now, I stick to my hypothesis. If anyone wants my project for debugging or study purposes, I am happy to share it. Any way I can help the Audacity team developing, I would be happy doing so.

Of course, if you have a project with the stereo interview track (without clicks) and music track, and can tell us steps to corrupt the audio we will be happy to investigate it.

If you Edit > Undo the stereo to mono conversion, does the problem go away, but reappear if you redo the conversion?

We would need you to open File > Check Dependencies... in the project, copying in any files listed there, then save and close your project in undamaged state. Make a zip of the AUP file and the _data folder and include a text file giving us the steps to create the distortions.

Are you saying for example that the disturbance at 26.15 seconds in your Soundcloud file is not in the original recording? That file is stereo, not mono.


Gale

[Dr. Killjoy]

The file doesn't have any dependencies. (I just did the check)
Since I closed the file and shut down my computer in the meantime, I can't undo/redo.

I will try to reproduce the error using parts of the original recordings in a new project. This will take some time, though.
By the way, in my forum profile, I noticed that I posted about this a few years ago, too. I was using a desktop computer, back then.