Wavosaur home Wavosaur
Wavosaur free audio editor support forum
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

'Churning' noise in background?

 
Post new topic   Reply to topic    Wavosaur Forum Index -> General
 
Author Message
theeclaire



Joined: 20 May 2008
Posts: 2

PostPosted: Tue May 20, 2008 4:50 pm    Post subject: 'Churning' noise in background? Reply with quote

Hi, another editing novice here (this may well have been covered already, but thought id check anyway...)

Basically im editing an interview and have managed to splice the questions and answers together, adjust the volume etc, but have a churning/'pulse' noise in the background of my audio file that is not removed when i increase the buffer settings. I know that this was not background noise when i conducted the interview. Have you come accross this before? if so, any ideas of how to get rid of it?

Thanks for your help!
Back to top
View user's profile Send private message
Rex
Site Admin


Joined: 05 Oct 2006
Posts: 779

PostPosted: Tue May 20, 2008 7:31 pm    Post subject: Reply with quote

Hello theeclaire

Is the noise present with all the files you open in Wavosaur ?
If this is possible can you send us a sample (upload on the internet or send to us by email) of the interview file ?

What is the format of the file ? (wav, mp3, vox ...)

I'm sure we'll find it what is going on!
Back to top
View user's profile Send private message
theeclaire



Joined: 20 May 2008
Posts: 2

PostPosted: Wed May 21, 2008 9:37 am    Post subject: Reply with quote

Thanks for getting back to me.
the file is in mp3 format and its actually the first file ive edited using wavosaur, although having just checked a freinds file, they dont have this problem. I have increased the volume on my file (my freinds were using the mic as handheld, but i was using it on a table to pick up both speakers - although this approach has worked for other users before) - could this account for it? Is there some kindof filter i could use?

what address can i email a sample to?
Thanks again for your help!
Back to top
View user's profile Send private message
Rex
Site Admin


Joined: 05 Oct 2006
Posts: 779

PostPosted: Wed May 21, 2008 11:06 am    Post subject: Reply with quote

You can send a sample at contact@wavosaur.com
Depending on the type of noise we'll find the better way to remove it (filter or FFT processing)
Back to top
View user's profile Send private message
DAM



Joined: 05 May 2008
Posts: 37

PostPosted: Wed May 21, 2008 11:44 am    Post subject: Reply with quote

maybe u have the wrong or not be dithered the file before u make a downsampling to mp3?
_________________
http://digital-audio-mastering.de
http://www.facebook.com/DigitalAudioMastering
Back to top
View user's profile Send private message Visit poster's website
Rex
Site Admin


Joined: 05 Oct 2006
Posts: 779

PostPosted: Wed May 21, 2008 4:52 pm    Post subject: Reply with quote

There are many problems with this file,
Some background noise (easily removable) but also a nasty distorsion, it sounds like a quantification problem (like if the sound was recorded @ 4 bit or less!).
Can you give precisions about the setup and all the step (what was the format of the recording, and if some conversion were applied to the file, like wav->mp3 or vox->mp3->wav etc...)

I quickly tried to "fix" the sound with some free VST plugins, i'll send you the result and if you like it i'll detail the setup and the process here.
Back to top
View user's profile Send private message
Rex
Site Admin


Joined: 05 Oct 2006
Posts: 779

PostPosted: Thu May 22, 2008 7:45 pm    Post subject: Reply with quote

here's a copy of the email i sent! it can be useful

- First you need some VST plugins, these are third party programs that can work with Wavosaur (this is why Wavosaur is powerful, the VST compatibility!)

1) download the reaplug package http://www.reaper.fm/reaplugs/reaplugs112.zip
2) extract the reaplugs files wherever you want on your hardrive
3) In Wavosaur, open the VST rack , click on the "Load VST" button, locate "reafir_standalone.dll" (from the reaplug package) and load it.
4) click on the "view" button to open the ReaFIR graphic interface

- Now this is the complex part! (the same procedure can be found here : http://www.wavosaur.com/tutorials/how-to-remove-noise.php )
removing the "churning" noise:

1) you can close the VST rack (but not the reaFIR interface)
2) check the "processing" box on the Wavosaur interface
3) on the reaFIR interface, select mode ->"subtract", and edit mode ->"precise" (these are dropdown menu)
4) now you have to find a part in your wav file that contains "only noise" (this is very important! only noise and no voice). You have to make a selection with only noise (it can be short, about 0.5 seconds).
note : it's easier to work with "loop mode on" http://www.wavosaur.com/quick-help/audio-transport-bar.php

5) when you have a good noisy selection, go to the ReaFIR interface and check "Automatically build noise profile", press "play" in Wavosaur --> the ReaFIR memorize the noise profile.

6) uncheck the "Automatically build noise profile", and in Wavosaur select all you file (menu edit-->select all)

7) press "play" --> the ReaFIR plugin substracts the noise in real-time, if there are too much artefacts, you can try to reduce the amount of substracting : on the reaFIR interface, hold the CTRL key on your keyboard and drag the red curve with your mouse (dragging down to reduce the amount of substracting).

If it sounds ok for you you can press the apply button on the Wavosaur interface to process the file.

- You have also a "hum" noise, a low frequency noise (only in the first part of the file), This is better to try to fix the "churning" noise with the method described above and fix the low frequency noise with another method. i let you make somes trials with the FFT method (ie using ReaFIR plugin). if you still have the low frequency noise and want to fix it i'll write to you the simple method for that (a method working for that kind of noise but not for he "churning" noise)

I'm also waiting before telling you more about dynamic compression, not too much at the same time!

Good luck
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Wavosaur Forum Index -> General All times are GMT
Page 1 of 1

 
Other topics :





Powered by phpBB © 2001, 2005 phpBB Group