Bad Sound Recordist, No Donut

[dkatz42]

I had a video post project drop into my lap yesterday. It looks like it will be a bit more challenging than I had expected, as some of the sound is AFU. Several of the clips have 60/120Hz hum (that I can handle) but it is apparent that the gain structure was hosed and there is analog clipping distortion in some of the material.

Other than hiring a hit man to take out the sound recordist (who supposedly was a pro), and being credited as Alan Smithee, does anyone have any suggestions on mitigating the distortion? Favorite tricks?

It's not unusable, but it is quite audible in the raw tracks.

Thanks in advance.

[djui5]

Getting rid of distortion is almost impossible from my experiences. Best thing to do is work around it...
Try to hide it with verb, eq, etc etc.

[dkatz42]

Originally Posted by djui5

Getting rid of distortion is almost impossible from my experiences. Best thing to do is work around it...
Try to hide it with verb, eq, etc etc.

Yeah, pretty much what I figured. That's what the music bed is for...

The good/sad thing is that once the pictures start, people stop listening critically. I guess this is the basis of the video pop star phenomenon.

[fifthcircle]

Getting rid of distortion is tough, but with good restoration tools, it is totally doable. The question is what do you have available.

You won't have good results with Waves or TC's plugins. You'll have great results with CEDAR, the Algorithmix professional plugs, an Audio Cube, Sonic NoNoise (can't say about PT's Sonic plugs, but I've done great stuff on the actual Sonic DAW) and other similar tools.

--Ben

[dkatz42]

Originally Posted by fifthcircle

Getting rid of distortion is tough, but with good restoration tools, it is totally doable. The question is what do you have available.

You won't have good results with Waves or TC's plugins. You'll have great results with CEDAR, the Algorithmix professional plugs, an Audio Cube, Sonic NoNoise (can't say about PT's Sonic plugs, but I've done great stuff on the actual Sonic DAW) and other similar tools.

--Ben

Thanks for the pointers.

Depending on compatibility and pricing, I may end up picking up something; I'm sure this won't be the last time I'm faced with lousy audio...

[MAProTulz]

I had pretty much the same problem with a video project a while back. I had it cleaned up by the wonderful folks at Independent Audio and their Cedar Cambridge. Couldn't totally get rid of the overloading preamp sound, but it did a VERY admirable job on some clips that were TOTALLY screwed. Independent Audio _sells_ the Cedar stuff, so they can point you to someone in your area with the tools to help you as much as possible.

[joaquin]

In my experience, there's not much you can do with that kind of distortion...un less you have a bounch of time to figure it out. Usually Time is a Luxury in TV POST, and most of the footage is one shot deal due to many factors.
I've done a lot of audio field recording for television, and if you know what your working with...should be always safe. But, sometimes, you are confronted with the most unpredictable sources, and then, you have two options:
1. you sacrifice your signal to noise ratio, and lower you pre-amp gain, also at the risk of practically lossing some information, or...
2. You take your chances, and RIDE Those FADERS!!...Men, sometime is like surfing waves!! It's a complete Trip. The Down side of this aproach, is ...Posible Distortion.
Now, I have my Theory: As you may actually Know, MTV, shape a lot of Television Formulas, like the "moving camera"...you know, when you dont know if the camera man wants to vomit or is the creative subtance of the momentum... Any way. My point is,that today, with all of this "Reality Shows", we are hearing more and more B@#%S$#@^ in the audio. Like was mentioned before, once the Eyes are full, the ear follows. I think that people, is getting used to deal with Distortion, as part of the "scene"...dam it, It my actually support the action!? Remember Blair witch Project...I don't, But, ...that type of Distorted Low Fi screaming in to the camera...may get your hairs up!! I know...this should be a Mixing option.
We should create portable mixers with compression...

probably my answer has nothing to do with your project at hand, but then.......

good luck, and probably one of Ben's suggestions will do......................Joaquin.

[fifthcircle]

Originally Posted by dkatz42

Depending on compatibility and pricing, I may end up picking up something; I'm sure this won't be the last time I'm faced with lousy audio...

The new Algorithmix stuff is expensive but a great bang for the buck. All 3 plugins are very high-end and capable of first rate work. They are still expensive (about $5K for all 3 of them which will run on Sequoia- Don't know about the stand alone versions), but compared to a Cedar Cambridge or Audio Cube system, they are a steal.

Usually Time is a Luxury in TV POST, and most of the footage is one shot deal due to many factors.

Absolutely, and that is where plugin based systems have their strength- between the Cube's VPIs and the stuff you can do with something like the Algorithmix, doing restoration is as easy as dropping a plugin in. Sure, obviously tweaking your settings takes some time, but you can dial in the rough settings quite quickly and in the end, your audio will be much better. Using the Cambridge means that you need to do a real-time capture of your material after getting your settings.

--Ben

[Tim Halligan]

Originally Posted by joaquin

We should create portable mixers with compression...

Most half-way decent EFP mixers have limiters...SQN, Audio Developments, Filmtech, PSC etc...

Cheers,
Tim

[joaquin]

Originally Posted by Tim Halligan

Most half-way decent EFP mixers have limiters...SQN, Audio Developments, Filmtech, PSC etc...

That's true, but In my experience, they are not able to avoid distortion. It may be they are not fast enough or ...I dont know. The mixer I use the most is an ALPHAMIX by PCS, and though I have always the limiter on, some loud "passages" just Over Load the output any way...Please tell me what's is your experience with the limiter's performances you use. Is there something that I'm missing?
PS. Always set the cameras at -20dbf and notice this distortion even when monitoring from the mixer, so no digital clipping...
Thanks for the info...................................................Joaquin.

[Tim Halligan]

Joaquin,
I'm not familiar with the Alphamix, but it sounds like everything you are doing is on the money.

Do you know if your limiter is pre or post masterpot?

Dive into the manual*** and find out how to change the limiter threshold...you'll probably have to take the side-plates off. Somewhere in there will be a pair of pots - that are conveniently unlabelled - that adjust the limiter. You'll more than likely need a jewellers' screwdriver. You'll also need an external tone generator...it will take some stuffing around to find the sweetspot.


***some bastard manufacturers don't include this in the ops manual, only in the tech manual...annoying and expensive

FWIW, I line up 0vu = -20dBFS (same as you) but run normal dials (limiter in) at -2 to -3 VU and never had a problem...

Hope this helps.


dkatz42: ADR - no outlay for you, production wears the costs, and you can charge extra...
However, don't let me stop you from killing the idiot recordist...



Cheers,
Tim

[joaquin]

Originally Posted by Tim Halligan

...Do you know if your limiter is pre or post masterpot?

Hi Tim. Thanks for the reply. I think there's where the problem is...my take is that it's pre master pot, so even when the input at the pre-amp is attenuated, that may be insuficient for the output to be safe...!? from the manual : "The limit threshold (activation level) is factory set at +3 on the meter. The limiters
compress the signal at approximately 2.7 to 1 ratio." It dosen't specify where in the signal chain is and neither if there's a trim pot where I can regulate it...I don't think there is. It also specify it's attack and release as: "1mS Attack, 100 mS Release...and I supouse it's also factory pre-set.
Any how......I'll keep searching, and I also support your suggestion...

don't let me stop you from killing the idiot recordist...

Thanks.................Joaquin

PS. here a link to the manual if anyone care.....http://www.professionalsound.com/cat...aMixmanual.pdf

[Tim Halligan]

Joaquin,
I looked through the manual...and you're going to have to find a tech manual.
Tech support at PSC should be able to help...you'd hope...but they'll likely charge you for the manual. At least they should be able to tell you if it IS adjustable...

Looking at the pic, I notice that the pre gain appears to be continuously variable, therefore I wonder if your pre gain is a shade hot? I wonder if you are actually hearing pre distortion as opposed to limiter artifacts, especially as 416's and some lavs are really hot mics...Try backing the pre down, and using the channel output pot to make up the difference.

Cheers,
Tim

[jabney]

Any idea how the $5k Algorithmix package compares with what they sell through CreamWare as osirisXP/REstore?

http://www.creamware.de/

Thanks,

John

[joaquin]

Thanks Tim.
Yes, the pre gain is continuously variable, and though I tend to print pretty Hot, I've been really successful with my approach. I also, sometimes, got to Mix the program, and when I did the recordings, no mayor problems, just a tad of EQ and compression. other times...you wouldn't believe the shitty audio that I had to work with...probably you know!?
By the way, I know that this may be a mistake from my part, but in this particular Mixer, I like to actually ride the Preamp pot, and live the fader set so my peaks in the pre-amp, meets the "0" in the LCD meters...That may be my problem!! because I usually work in pretty un-controlled environments, where the sound source moves around a lot. At the same time, this aproach gives me the best shot at capturing the best posible signal... You are right about the Lavs, but those I try to use only under controlled situations. Basically, I always have a EV RN50, for the hostess and the sennheiser with the Boom pole...always use the Pad in noisy situations.
I try to get some information from PCS before, but no answer. Any way. Thank you very much for your Input, and I'll keep trying to improve my craft

[joaquin]

Originally Posted by joaquin

...By the way, I know that this may be a mistake from my part, but in this particular Mixer, I like to actually ride the Preamp pot, and live the fader set so my peaks in the pre-amp, meets the "0" in the LCD meters...

Actually It's no mistake, since I'm just recording, not mixing, the stronger and clearer my signal is... the better. My goal is to get the best posible signal from each source...I'm just tracking to two channels...Left and Right, one for each mic...usually just two; so the preamp gain is my ally. If I were to mix the signals, then the faders would be it...am I right or...am I right!?

[dach]

If anyone is using any of the Cedar stuff, take a look at SoundCleaner. With all the flaws, limitations and counter-intuitive interface, this is still the best overall for salvaging the worst of the unsalvagable. I use it stand alone then xfer the files to PT or PC for prettying up. We have done direct comparisons to several of the Cedar boxes as well as just about every piece of software available including Algorithmix.

http://www.speechpro.com/production/?fid=7&id=322

You may also want to contact some of the folks who do this work directly in MATLAB. I've worked will all these guys before and they are capable of things you wouldn't believe.

http://www.ces.on.ca/audio/Contact.htm >Archie Bowen, Ph. d., P. Eng.

Chuck

[SiliconAudioLab]

dkatz,

Just send me a snippet - I can clean it for ya. PM me.

[SiliconAudioLab]

Ok, Here ya go. Let me know what think.

http://www.siliconaudiolabs.com/media/CleanedBySAL.wav

http://www.siliconaudiolabs.com/media/Original.wav

[SiliconAudioLab]

Thanks dzatz,

It's mostly a time thing. It CAN be cleaned to as close to perfection as possible but your deadline of this weekend made it a "quickie pass" process.

I some quick EQ (which "could" been left out of the process - maybe).

One thing that can help is having a pass of the un distorted stuff for a target reference and also a snippet of the noise floor for reference for the Cedar.

I shall induldge my diebetic impulses.

[dkatz42]

Originally Posted by SiliconAudioLab

Thanks dzatz,

It's mostly a time thing. It CAN be cleaned to as close to perfection as possible but your deadline of this weekend made it a "quickie pass" process.

I some quick EQ (which "could" been left out of the process - maybe).

One thing that can help is having a pass of the un distorted stuff for a target reference and also a snippet of the noise floor for reference for the Cedar.

I shall induldge my diebetic impulses.

No worries, and your help is most appreciated. If anything further happens with this piece (it's going to debut in front of a ballroom full of people at a fundraising dinner in Portland on Saturday) we can look into it further. Meantime, we can blame the distortion on the PA. (Maybe we should warn the sound guy so he doesn't freak...)

When all else fails there is always the usually depressing mantra that people stop listening as soon as they start watching (though in this case it's a good thing.) I have to keep the video window dragged mostly off of the screen so that I don't fall into the same trap!

[joaquin]

Hi SiliconAudioLab. I think that the cleaning of the distortion on top was pretty good, though, the Cut you did in the low frequencies may be as damaging for the "presence" of the audio as the original distortion, and, I my self feel that sometime the repeated digital processing of audio adds another undesired artifacts...sort of a grainy quality...Well, just IMHO.
Anyway thanks for the samples and the work you put in to it

[SiliconAudioLab]

Yep - I agree with both you guys on all points. The 250 hz cut was to help the cedar stop hitting on that freq - at which point there was NO way back.

I'll hit it ONE more time without ANY EQ at all (just because I obsess).

Do yourself a favor and upload the whole distorted bit to my site - ya never know it be magic this time and you'll have just enough time to yank it off and plunk it in.