Removing High Pitch whine in audio?

S

sean90291

Veteran
I know there are some EQ effects in Avid. But I've never been very successful at using them. I tend to just use the pre-set audio effects.

But now I'm stuck with some audio with a very high pitch whine. I think it's a nearby streetlight or electric box or something. Very high. I should be able to strip it out without affecting the dialogue...if only I knew how.

Can someone tell me what steps I use with the Audio Suite 4-band EQ effect to get rid of high pitch whines? I know, I just "play with the EQ" effect. But I need something more specific, I'm afriad. I don't even know what Hz signal a high-pitch sound would be coming in at!
 
The best way to find out is to test. Starting with the highest frequency, lower each frequency lever and play the audio. Once you find a setting that removes that whine, keep it. If it doesn't remove the whine, raise the lever back up to its normal position and go to the next lever down.
There's probably an easier way to do this using a preset, but I'm not familiar with Avid presets, and this is a tried and true method.

Hope this helps!
 
I'm not in front of the Avid - I'm doing this from memory. Apologies if I get it wrong.
Apply the EQ effect , this isn't the same as the 4 band Audio suite effect. First drop the gain on the mid tones all the way down. Below the fader there's a pulldown menu for freq width. Select the narrowest width, it think it's 1/8. It will be easy to tell from looking at the graph. There should be a horizontal slider with a low freq (400Hz?) on the far left and a high freq on the far right. Drag this slider to move the notch up and down the graph until you can find the problem freq. This process is basically building a notch filter. To see what a notch filter looks like on the graph select the 60hz hum preset. Sorry if this makes little sense - I'll sit down at the Avid in the morning and try to clarify the process if no one else chimes in.

A few things to consider. If you have any kind of budget available and this is an important project - consider pushing an OMF to Pro Tools and having a sound designer try to clean up the noise. Pro Tools has a much more powerful toolset.

Also, more often than not noise is spread over a large frequency range so it's very difficult to dial out the noise without crushing the wanted audio.

good luck
 
Okay, I'm gonna give milksac's procedure a try. Will report back momentarily. Thank you!!!!!

And actually it's STARTING to make some sense, milksac. I'm looking at my Audio EQ tool and the far right freq width is set at 15kHz. The middle is 2 Oct. And the far left is 50 Hz. These numbers aren't according with the ones you're calling up from memory (I'm surprised you can do this from memory at all--you must be very familiar with your Avid).

So I'm gonna try to use your steps, even though the freq numbers are different than you recall.

(No budget and no time to send to a Pro Tools guy. Project due on Friday. Screens next week! Yikes.)

Update: alas, none of the sliders are attacking the highest pitch of the whine. It's VERY high pitch. What leve/freqency would be most likely to attack such a high frequency do you think? What Hz is the human voice at?

Update: darn. nada. nothing. Other sounds, like traffic roar and stuff get diminished, but high pitch freqency remains. I've never had luck cleaning audio with Avid's built in Audio except for removing minor tape hiss (which the pre-set does a nice job of removing).
 
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Oh my, I've been spoiled for far too long. More often than not I push an OMF to a sound designer for final mix. I just dug around the Audio Suite tools and had a look at the 7 band EQ. A better tool for what you're trying to accomplish. Sorry for the misinformation. Try creating a notch filter using the Audio Suite 7 band EQ. It might be easier to dial in the problem frequency. Also you could try rolling off the high end to eliminate the noise. The problem here is that it's real easy to turn the audio you're trying to keep into mud.

good luck.
 
Sound Ideas

Sound Ideas

If the noise is from a metal halide street light, it is MANY frequencies at once and you are better off getting a ProTools guy to fix it. Using Broadband Noise Reduction.

But... You could start a 16kHz and roll that off with a Low Pass Filter 12dB/Octave. That will get you "FM Radio" frequency response. May not be desirable. Or bump up 3kHz a touch. That's where voice lives.

Good Luck!
 
Adobe Audition has awesome spectral editing capabilities.

I'm sure other DAW's also do. You can target a specific freq. range, and remove, or modify just that range. hopefully nothing important is in that range you have a problem with.

could be a live saver, it's VERY powerful. The spot healing brush is also awesome in Audition, this could help you alot!

Derrick
 
I will have to learn Audition once and for all.

I did play with the Avid 7-band EQ effect. I'd never tried it before! Very colorful interface. And totally baffling in terms of the number of options. I got some learnin' to do. But I was able to help the sound just by experimenting (even having no clue what I was doing otherwise). Will have to find someone to help me with this clip this round. But I'm determined to learn at least some basic audio cleaning skills.
 
I had something like this once, and couldn't get much joy out of "audiosuite" tools. But I exported the whole track, and imported it into audacity- which is a free downloadable sound app. It has a filter that lets you show it what you want to get rid of- two or three seconds of just the whine- and then it will strip it out. I had to play with the slider- as I remember, on all but the minimum setting it was pretty harsh- but I did get an audio track I could use ok.
If you got a budget- or friends with the tools- there's an application called "soundsoap"- forget who makes it- that's pretty impressive. But audition worked for this (it was the interviewers mic, luckily not the subject- and I could mix a bit of the guy we were interviwing's mic in as well to and it sounded ok.) Worth a try!
 
Hm, I will try audacity next time. I've never used it for cleaning sound. I found that I was eventually able to get some satisfaction from the Audio Suite 7 band EQ effect. There's a lot of power there. But as was mentioned above, it seems as if that "high pitch whine" actually occupied several frequencies (bummer) and I ended up simply not doing anything to strip out the offending sounds, and instead added more ambient noise to make the whine more natural. It's a shame, cuz the film is screening at TIFF. But it's the best I could do with the time and money! Thanks for the advice.
 
If you were not in a tight fix, I would offer to send me the audio and clean it for you.....I have the tools but you need to upload it to an ftp and give me time.....how long is the take ?

you definately need a pro audio solution because as juju says its more than one frequency. I wonder how this was picked up? which mic ? was there a long cable ? its quite difficult to have such injections....I would check my cables for the future.
 
Thanks timbook2. Very generous. The whine was picked up with an ME66 shotgun mic.

Anyhow, the film screened yesterday. The sound turned out better than I imagined it would. I really do need to get better audio solutions in the future though.
 
I do audio post all day... just starting with the editing on the Avid and FCP. The one thing I notice is that most low budget/indie projects don't spend money on audio post. A seasoned veteran can work wonders for the audio, making the finished product really shine. In my opinion, good audio separates an OK film from a great one.

Sorry for the rant.

carry on.
 
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