Any way to cleanup really ugly/hot audio?

qsnow1 wrote on 9/13/2007, 12:28 AM
I was at a concert and the only thing I had to record with was the video recorder on my camera. While it does a pretty good job, the microphone was no were close to being able to handle the loud concert.

When playing the video's back, the audio has a LOT of distortion (like when you play something too loud on crappy speakers).

Is there any way to clean it up so it's 'somewhat' usable in Vegas 7 or some other product?

Thanks for any ideas.

Comments

farss wrote on 9/13/2007, 12:40 AM
I've had some success using the Clipped Peak Restoration tool in Sound Forge but that really only works well for digital clipping and mild cases at that.
How do the waveforms look on the Vegas T/L?
Did you have AGC on in the camera?
What sort of camera?

In general with audio it's easy to go from Good to Great. From Bad to Good is way harder if not impossible most of the time.
John_Cline wrote on 9/13/2007, 12:53 AM
farss is right, it's pretty unlikely that you can recover the audio. No doubt, the mics were overloaded, which then clipped the mic preamps and then probably clipped the digital audio signal recorded to tape. This type of analog overload is highly non-linear. Like farss said, if it were just relatively mild digital clipping, it could probably be salvaged. You can try the clipped peak restoration in Sound Forge, but I really don't think it's going to make any significant difference.
digifish wrote on 9/13/2007, 1:27 AM
Out of interest can you post a 5-10 second example of the audio? I'd be interested to see what's possible.

digifish
Grazie wrote on 9/13/2007, 1:30 AM
http://madison.thewikies.com/index.phpTry posting here[/link]

Yeah, I'd like to have a go too.

Grazie
MichaelS wrote on 9/13/2007, 7:27 AM
There's a good article on recovering bad audio in a recent magazine, Sudio Monthly Vol. 29/No. 8: "Rescue Badly Recorded Audio with Sony Sound Forge 9 and iZotope", by Justin Lassen.

Although limited by the damage done, the technique provided seems logical and may help to improve your situation.

rs170a wrote on 9/13/2007, 7:33 AM
There's a good article on recovering bad audio ...

Here's the link to that article.

Mike
kdm wrote on 9/13/2007, 7:41 AM
As already advised, it of course depends on how bad it is distorted, but with a concert, my guess is it's beyond repair given your description - simply because the frequency range and spl of a concert.

Last year I took a restoration project that was a simple interview where the camera operator forgot to check audio levels - the gain was probably set 6dB-10dB too hot with distortion well down into most every frequency range, and dynamic level. Even Algorithmix restoration tools couldn't fix it to any satisfactory level. Cedar is the only system that might be a little more capable than Algorithmix, but even that would have only lessened the distortion's character.

The problem with distortion is that if it is even a little noticeable by the average listener you can, and likely will degrade the audio during restoration as much or more than the distortion. With voice, you can get something audible back, but with full range music, it will still be mostly noise, or a narrow band of semi-audible music. Worth a try of course. Best of luck.
farss wrote on 9/13/2007, 8:29 AM
OK,
now here's the thing. Clipped Peak Restoration only works on hard digital clipping. Many's the time I've read posts along the lines of "I've tried using CPR but it didn't do anything". Well for sure it will not if doesn't see any samples at 0dB for more than a few consecutive samples! The Find Clipped Peaks tool is a good way to check.
So your audio can be distorted in the analogue realm or even someone has tried to fix a clipped file by knocking the level down. In either case CPR will do nothing.

Simplest solution I've found is to in SF add a little volume, just enough to force hard clipping. Then use Clipped Peak Restoration as explained in the article.

There's no magic though. I've rescued the odd recording of simple audio like speech. Complex sounds like a concert will entail you're probably not going to have any luck with, worth a try but I've had little to zero success. Also with long recordings each little part may need individual attention and it's just too much work, for very little improvement anyway.

Bob.
jbrawn wrote on 9/13/2007, 10:46 AM
I was in this situation. I contacted the FOH sound guy, and he had made a personal recording of the concert off the board. He mailed me a long MP3 file on a CD, and it saved me.

Good Luck,

John.
qsnow1 wrote on 9/13/2007, 10:54 AM
Thanks for the responses. I will post some sample clips when I get back to the hotel tonight. It was a private smash mouth concert so it would be nice to at least show the family a little bit of it to make them jealous :).

As far as the camera it is a panasonic dmc_fz18. Its brand new (was released for purchase about 6 days ago as a matter of fact. For a non-video camera the quality of the movie capture was prety darn good. As for ACG that farss asked about, I honestly don't know. I will have to look and see - I haven't had enough time to really know what I'm doing with it :)
qsnow1 wrote on 9/15/2007, 8:31 PM
Took me a bit longer than expected to get back to an internet connection and get some samples uploaded... I've posted 4 files, 2 different samples in .WAV and .MP3 format.

-- Sorry, I don't seem to know how to embed ftp links appropriately. --

ftp://temp:temp@67.79.37.165/Distorted1.wav

ftp://temp:temp@67.79.37.165/Distorted1.mp3

ftp://temp:temp@67.79.37.165/Distorted2.wav

ftp://temp:temp@67.79.37.165/Distorted2.mp3
farss wrote on 9/15/2007, 9:37 PM
Sorry to say this but that is way past the point of no return.
If nothing else the camera's AGC killed it.
Probably the microphones and / or the preamps were overloaded as well.

Bob.
apit34356 wrote on 9/15/2007, 10:40 PM
"In general with audio it's easy to go from Good to Great. From Bad to Good is way harder if not impossible most of the time." Kinda like being an editor, director, writer, gangster, politician----- bad to good is one in a million shot.
GlennChan wrote on 9/15/2007, 11:15 PM
You can remove some of the buziness via noise reduction. But what's left is still munged.

Grazie wrote on 9/15/2007, 11:28 PM
Yikes!!

Something was very HOT indeed!

What I AM seeing on my V8 waveform is that the actual recorded data is within parameters. However it is the total distortion that is perplexing me? AGC being applied and then you thinking I THEN need to turn down the levels, could have produced this, this painful stuff. Really very painful - sorry.

What also might have contributed to this would be that the actual speaker output could have been coming from a board that was being "operated" using too much gain. I've had it with sound guys who just up the gain and the room had distortion!!! Oh yeah, what happens next is that people speaking, yell louder, 'cos of the distortion . . and soooo, what happens? MORE GAIN!! You end up with nobody hearing what's coming outta the Speakers and not hearing what anybody is saying either!!

In in any case, I listen to the speakers first, and having a "word" with sound-guy get the board sorted out; slap on MIC attenuation - either in-camera OR my in-line XLR attenuator ( now THAT'S for heavy stuff!); I do NOT use AGC; I DO use my beachtek; I cup my hands over my cans crouch/bend down and really REALLY concentrate on what IS coming through my mic/s and study those meters!!

In video work GAIN=GRAIN, in audio GAIN=PAIN !!

Sorry guy, I can't see any way of salvaging any of this. But lesson learnt - yes? I have an excellent example of my work I ruined by something similar. Yah does it maybe once or twice and then . . well .. .

Regards,

Grazie
John_Cline wrote on 9/15/2007, 11:58 PM
It sounds to me that the microphones are overloaded, after that it just got worse as it hits the pre-amps and AGC. Keep in mind that most camcorders with built-in mics have their gain structure set to pick up voice at 10 or so feet, not a band playing at 110db.

John
TGS wrote on 9/16/2007, 1:28 AM
That was so distorted, I couldn't tell if that was the real band or just somebody else playing the old hit. Unfixable
They may be hope though. If that was the real band, there's more than likely to be quite a few bootleg audio recordings and you'll just have to find one and sync it up.
Probably some bit torrent sites or something.
The bad news, you may not find the audio for quite a while
qsnow1 wrote on 9/16/2007, 9:46 PM
Thanks for the attempts and thoughts :-) I'm definately an audio NOOB so I'm having to look up a lot of the information posted here to find out what everyones really talking about :-)

I didn't find any info in my camera book about the microphone and if it had an AGC (auto gain control I assume) so it's either there and on by default or doesn't exist. Like I said earlier, I wasn't expecting them to throw a concert, so I didn't bring my Sony DVR-403 recorder, which I think would have done a MUCH better job at sound than my digital camera.

Regarding the sound guy and the post about just adding GAIN to boost signals -- I'm not sure how it fits in (if it does) but when the concert started the music severely overshadowed the vocals. I noticed the lead singer went over to the sound guy a couple times and talked to him, then all of a sudden we could hear the vocals over the music. Either way, everything was definately VERY LOUD, even with it being outdoors.

Good suggestion on looking around the internet for other 'captures' and snagging their sound. Hopefully I can match some up. There's a few on YouTube right now (a search for: vmworld smash mouth)- a little distortion in theirs too, but they were much further away from the speakers so I think that helped some.
farss wrote on 9/16/2007, 11:18 PM
You could try the Tapers forum, run by Doug Ode.
Lots of good oil there on making concert recordings and who knows, you might get lucky and find someone who was taping the concert. Not all these things are covert ops either it seems, some bands permit or even encourage taping of their concerts.

Bob.
Grazie wrote on 9/16/2007, 11:23 PM
Exactly how near to the speakers were you? g
qsnow1 wrote on 9/17/2007, 5:52 PM
I was about 4 people rows (standing) back from the stage - in the middle... So I'd say I was probably 20 feet from both big speakers they had sitting on the stage. There were other speakers hanging and such as well.
TGS wrote on 9/17/2007, 10:19 PM
Although I've never really looked into these type of sites, I've heard pretty good reports about this one.
http://blogger.xs4all.nl/werksman/archive/2005/04/09/34376.aspx
when you get there, dbl click on the orange 'dimeadozen dawt org', THE SMALL ONE UNDER THE FIRST PARAGRAPH OF WHITE WRITING.
When you get to the RSS page, just scroll down to the bottom to see a few of the things they have.
My understanding is, it's free to join and download, but you are requested to help send some bit torrent info to help out. Some of the things I've seen listed here are in the 800MB range and are merely audio files.
I think they only allow a certain amount of members at a time, but the members change often. So, if you can't join right away, keep trying. You don't have to join to see some of the listings, but maybe to see all the listings. I did join once, and checked the site out, but never had the time to invest, so never downloaded and my account / password is no good now
This is the type of site you may find the entire audio for the show you want. There may be many sites similar to this and I don't have a clue where to find them. I just happened to hear about this one on am radio.
As far as I know, these are 100% legal. There were some bands, where I couldn't find anything (Like Jimi Hendrix, who has hundreds of bootlegs) and others that seemed to be encouraging people to copy their bootlegs. (Metal, Blues, Rock, and some big names too)
I know that bootleggers will trade music, legal or not, Not necessarily for money, but just because they want the biggest collection of a certain band / or bands.