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What is this noise?

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What is this noise?

PostPosted: Thu Jul 18, 2019 2:37 pm
by Hexo
Hello everybody,

There are some kinds of crackle like distortions in some of my records. like this one:
https://drive.google.com/file/d/1dMIpxrMzhdJT5TjS4oTw6tTF5RqCoZso/view?usp=sharing
I can't tell if they're acoustically in the source or are being generated somewhere in my circuit. Although some noises are apparently in her voice but there are other things too!

What do you think?

Re: What is this noise?

PostPosted: Thu Jul 18, 2019 7:30 pm
by BJG145
It's difficult to tell isn't it...eg this very short fragment has two subtle clicks in it and I'm not sure if those correspond to the humps or not, as there's also a couple of ululations. There aren't any obvious glitch/spikes I could see, though the waveform isn't all perfectly rounded; if you zoom in closely it looks a bit dented. (?)

Image

At first I thought they sounded electrical...then I thought they were mouth noises...but it's in the middle of a vowel...?

I dunno, though I suspect it's a recording issue.

(You might be able to clean it up quite effectively with the right plugins.)

Re: What is this noise?

PostPosted: Fri Jul 19, 2019 12:54 am
by James Perrett
I had a quick look on Adobe Audition's spectral view and they look very much like missing samples to me. This could either be down to the analogue to digital convertor and computer word clocks not being synchronised properly or it could be down to the computer not quite keeping up with the data coming in.

Re: What is this noise?

PostPosted: Fri Jul 19, 2019 4:03 am
by Martin Walker
James Perrett wrote:I had a quick look on Adobe Audition's spectral view and they look very much like missing samples to me. This could either be down to the analogue to digital convertor and computer word clocks not being synchronised properly or it could be down to the computer not quite keeping up with the data coming in.

Sometimes even using a poor quality digital cable to connect digital audio clocks and the like can result in occasional ticks, clicks and missing samples.

However, wordclock connections tend to be better than coaxial S/PDIF in this respect.


Martin

Re: What is this noise?

PostPosted: Sat Jul 20, 2019 3:31 pm
by Hexo
BJG145 wrote:It's difficult to tell isn't it...eg this very short fragment has two subtle clicks in it and I'm not sure if those correspond to the humps or not, as there's also a couple of ululations. There aren't any obvious glitch/spikes I could see, though the waveform isn't all perfectly rounded; if you zoom in closely it looks a bit dented. (?)

Image

At first I thought they sounded electrical...then I thought they were mouth noises...but it's in the middle of a vowel...?

I dunno, though I suspect it's a recording issue.

(You might be able to clean it up quite effectively with the right plugins.)

Thanks for your deep investigations, I can imagine automating a lowpass filter on click moments, but looks like you have other plug-in tricks in mind. What do you suggest?

Re: What is this noise?

PostPosted: Sat Jul 20, 2019 3:36 pm
by Hexo
James Perrett wrote:I had a quick look on Adobe Audition's spectral view and they look very much like missing samples to me. This could either be down to the analogue to digital convertor and computer word clocks not being synchronised properly or it could be down to the computer not quite keeping up with the data coming in.


Martin Walker wrote:
James Perrett wrote:I had a quick look on Adobe Audition's spectral view and they look very much like missing samples to me. This could either be down to the analogue to digital convertor and computer word clocks not being synchronised properly or it could be down to the computer not quite keeping up with the data coming in.

Sometimes even using a poor quality digital cable to connect digital audio clocks and the like can result in occasional ticks, clicks and missing samples.

However, wordclock connections tend to be better than coaxial S/PDIF in this respect.


Martin


Great thoughts, It sounds like jitter to my ears too. My whole A/D D/A and clock package is in a Lynx Aurora8 unit, connected to a mac with a usb cable and a usb card before that. I'll take all my chances testing alternative parts which is just the usb cable now :D
Thanks in advance.