I've shot some video and used an external mic
Unfortunately, there is a buzz at the end of every word
It's still OK - but I cant use without getting rid of the buzz sound
Can someone advise of what I need to do
I've got Audacity - will that do the job?
I assume I just need to run through a filter or something?
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i've sent u a link to the videos in a pm
i didn't want to give the link publicly
let me know what u think
Try the Noise Removal filter in Audacity. Grab a sample of the buzz, hopefully by itself, and use that as a template for the noise filter. It might take some playing with the settings. No idea if this will work with your audio track, but it's worth a try.
Using the latest beta version, load you sound file, and highlight with the mouse a small section that represents the noise you want to remove. Click on Effects -> Noise Removal -> Get Noise Profile. Now highlight the entire file (or a good sample with the noise in it), and click on Effects -> Noise Removal -> then OK to remove the noise.
Note : This type of noise removal tool works best for constant noises, like air conditioning hum in the background. You sample a quite section of audio with just the hum, and you can remove the hum from everything. It does not work so well with short, sporadic noises or noises that vary more than a little. This is why I have doubts about it fixing your issue.
However you lose nothing by trying. You may find that you have to take a sample from a small section, then remove the noise from just that section, then do the next section.
i've done that - but no luck
the noise removal tool seems to be a bit like revolutionary soap powder we had in the uk about 10+ years ago
it used to work by removing chunks of your clothing where there was dirt - leaving you with a clean item - but one now with holes in!
it produces something completely unusable + doesn't remove the buzz noise
its not a constant noise
really don't know what to do
The distortion is across all the speech because it is a recording issue. Perhaps if you can provide just a few seconds (I understand it is a commercial in confidence type thing - but a few seconds of nondescript dialogue out of context couldn't hurt) so people with different kit can play. What you PM's me is not very useful because it has the bacjground music already mixed in. To have any hope of making this work we need just the dialogue recording (or a sample thereof)
*thanks* for the reply
i'll get the audio without music a little later and will post a sample - all help would be really appreciated
ok, see the attached file
this is about 15 seconds and clearly shows the problem of the buzz sound
let me know what you think
The 'buzz' you describe is clipping. There are two possible causes. Either the microphone analogue audio chain is being overdriven, or the recorded audio level exceeds the maximum input to the digitall A/D converter.
On the face of it, it looks as if yours was caused by an analogue overload. Certainly the file is nowhere near the 'digital' 16 bit A/D limit. This analogue overload is almost impossible to correct very well.
However, in this case,some of the high level clipping is reasonably 'clean' - although the harmonic distortion introduced by the clipping action, to the overall waveform, suggests it is analogue.
So you can probably achieve some improvement (don't expect miracles!) by 'faking' the signal to look like digital clipping, and applying a clip restoration tool with an audio editing program.
It's much more difficult however, removing much of the underlying 'edginess' of the harmonic distortion at lower levels. That's a bit like trying to extract the egg intact, from a baked cake!
I use Cool Edit (bit out of date, but ity suits my needs!), and a quick try with your sample file shows the kind of thing I mean. New sample attached.
As I say, you can't expect miracles, but it might show some improvement.
Edit: I notice you mention Audacity in your earlier post. I believe the latest beta version of Audacity includes a plug in called 'Clip fix'. I imagine it is similar to what I have attempted in Cool Edit, although as it's about 10 years newer, it might be significantly better! Got to be worth a try? (as it's free!)
Further edit: I had a (very) quick play with your original file in Audacity, with the 'Clip Fix' effect. Setting the max amplitude to -10dB, and applying a threshold of 65% seems to be a good starting point. The results were at least as good, and I think better, than my Cool Edit attempt. So definitely worth a try!
Further further edit: It's definitely better! further clip attached -('andrewaud.wav' is the Audacity one)
Last edited by pippas; 29th Oct 2010 at 17:10. Reason: extra info
A notch filter at 133 Hz will remove some of the boominess.
Last edited by jagabo; 30th Oct 2010 at 06:07.
As I say, hopefully you can make some improvement --glad to be able to suggest something that might prove useful!
I take Jagabo's point about the boominess. In fact I did do some EQ adjustments on the file I posted, and I think there could well be further improvements, with a bit of' tweaking' EQ wise.
In addition to Jagabo's notch filter suggestion, try a bit of 'presence' lift say around 2.5KHz, and possibly even more low frequency cutting?
The problem is that, in addition to the high level 'clipping' damage that you can probably restore, the fact that it is analogue clipping, means it has left harmonic distortion 'scars' in the main body of the audio, and they are notoriously difficult (if not impossible) to isolate and repair. Careful playing with 1/3 octave equalisation might help a bit......
pippas, u said "Setting the max amplitude to -10dB"
where do i do that?
i got some freelancers to bid on improving the sound for $30
i've had a few results that are better than the samples u gave
i will probably go with one of these
It's a difficult problem, but there are some clever guys out there, both writing all sorts of plugins (some very pro good ones among them) - and knowing how to get the best out of them. It's always good to hear what can be done, if you really know what you're doing!