Subject:noise reduction and reverb

Posted by: joejon

Date:3/11/2004 7:45:38 AM

I recently bought Noise Reduction 2.0. I also have Vegas 4 Editing Workshop that talks a little about it and I also have Sound Forge 6 Power (I have Sound Forge 7). But the second book doesn't give any information on noise reduction (surprisingly). These are what they did tell me:
take the smallest sample possible (100ms),
it's better to apply it many times at smaller settings (but they don't tell me
what they consider a smaller setting - 10, 20, 30, ???).
I have a lot of school band music (with a lot of audience and other room noise) I want to use it with. If you have any suggestions for settings on the following, I would appreciate it:
-Reduce noise by slider (they suggest a small setting and apply many times,
but what does that mean?)
-Noise bias - it seems when I move this from 0, it takes out some music also.
-Noiseprint - is it better to use Average or Peak?
-Attack and Release speeds - defaults are 90 and 50.
-High-self start freq - default is 7000.
-High-self gain - default is 3.
I also have been playing with the Acoustic Mirror effect a little, but there again, it's hard to change one setting, listen, change another, listen, reset the previous setting, listen, on and on. Any suggestions would be helpful:
-Wet slider
-Low-self start freq - default is off
-High-self start freq - default is off
-Quality - ranges from 1 to 5 (on 5 playback hesitates once in a while when played in real time/preview).
These are the steps I now use to process audio. I don't know if it makes a difference the order.
1. Noise Reduction
2. Clipped Peak Restoration or Normalize (what should my output levels be after this?)
3. Fix any clicks
4. Maybe apply acoustic mirror effect
I'm not sure what to do with many of the other settings yet because I haven't had time to play with them much. I know, in the books, it says that EQ and Compression are important, but I don't understand them yet.
Thanks for any help.

Subject:RE: noise reduction and reverb

Reply by: RiRo

Date:3/11/2004 12:33:12 PM

Howdy joejon,

This is tough. First, the kind of noise you are trying to remove may be impossible to remove without destroying the sound you are trying to keep. Noise Reduction is the best thing I have run across for removing consistant noise, but it cannot remove a cough or a crying baby. If you have an air conditioner running and a good sample of just that noise, you can say bye bye to the noise without touching your original content. That is what it works best at.

As for settings, you have to use your ears. As for sample, I try to grab a large chunk if I can get it with only the noise I want removed. By large, maybe a half second if it is there. It will work with small samples, I just like bigger if it is available as a pure noise sample.

Smaller settings... I'd say 6-9 db. Maybe 12 if you make three passes. But even with multiple passes, you will not be able to take a file down to dead quiet without some artifacts.

RiRo

Subject:RE: noise reduction and reverb

Reply by: Rednroll

Date:3/11/2004 3:26:19 PM

As for the settings and what each does, they are well outlined if you click on the "Help" button located on the plugin screen. Since, you're asking for help on what the adjustments do, that should have been your first clue. Also within this same help button is a tutorial outlining how to use the plugin.

Subject:RE: noise reduction and reverb

Reply by: farss

Date:3/13/2004 6:03:26 AM

Applause you'll never get rid of. I might be wrong but I can see no way anything can differentiate that from what you need to keep. Its got a fairly broad spectrum and it varies a lot over time.

If you had a clean track of just the applause then you might have a chance by subtracting that from the mix but somehow I doubt you'd have that.

Maybe it's a case of 'if you can't loose it use it'.

Subject:RE: noise reduction and reverb

Reply by: joejon

Date:3/13/2004 4:40:23 PM

I don't need to get rid of the applause, I just cut that after the end of each song. It's more the noise of the room which includes some motor and blower noise and general audience rustling. But I don't know what settings to use for the best results. Someone suggested about 10db with maybe 3 passes. That didn't seem like quite enough, but I don't want to cut the music out either. It's harder to reduce coughs and kid noises, but I have had some success with various things. Such as Copy Other Channel if it isn't as pronounced on that channel. Or if the noise is loudest in a silent part between songs of a medely, I do a quick graphic fade out and back in. I don't understand how to use some of the other settings I listed in my original post such as setting the Mode, Attack, Release, High-self start freq, and High-self gain in the Noise Reduction Window. Also, is there a certain order I should be doing things, as also asked in my original post?

Subject:RE: noise reduction and reverb

Reply by: rraud

Date:3/13/2004 4:56:11 PM

If your audio was recorded with a camera mounted or general ambient mic, SF Noise reduction CAN attenuate some of the AC and other din type noise with the above steps.... . But .... NR cannot work magic, same for other high priced applications. You cannot get rid of coughs and the like without literally deleting or replacing them. (if your lucky/w the same notes or chours', ect)
As for NR, EQ and other settings, you will have to experment for optimum performance.
The term used in pro-audio is: Polishing a turd... Or to be polite, Make a silk purse out of of sow's ear.
Sorry joejon I wish I coulld be more help, but I'm think'in your SOL.