View Full Version : Low levels


Kathy Smith
May 19th, 2013, 07:21 AM
Hi,

First, let me state that I am a novice to audio recording so of course I screwed up and recorded the levels too low. I need to boost the levels now but that also brings the background noise up. Any software I could use to fix the problem? I looked at Izotope RX and Izotope Ozone 5. Not sure which one would d a better jobs. Any others out there that I should look at?

Greg Miller
May 19th, 2013, 07:48 AM
Hi Kathy, and welcome to the forum.

I think folks will be better able to advise you if they can hear what you're asking about.

I suggest that you post a short, unaltered .wav file that contains two things: a section with just background noise but no desired sounds, and a section with some of the sound that you want (which will of course also have the background noise).

Some folks might even import the file into the software they use, and try a few NR tools to reduce the noise, before making a specific suggestion for you.

Nate Haustein
May 19th, 2013, 07:52 AM
RX2 is a magical program that would probably be the one to use. There is a free demo you can download to see if it works for your particular issue.

Kathy Smith
May 19th, 2013, 08:27 AM
Hi Kathy, and welcome to the forum.

I think folks will be better able to advise you if they can hear what you're asking about.

I suggest that you post a short, unaltered .wav file that contains two things: a section with just background noise but no desired sounds, and a section with some of the sound that you want (which will of course also have the background noise).

Some folks might even import the file into the software they use, and try a few NR tools to reduce the noise, before making a specific suggestion for you.
Thanks, I will do that tomorrow.

Kathy Smith
May 19th, 2013, 08:31 AM
RX2 is a magical program that would probably be the one to use. There is a free demo you can download to see if it works for your particular issue.
Nate, any idea how it compares to Adobe Audition?

Richard Crowley
May 19th, 2013, 09:03 AM
Audition is an general-purpose audio editing tool. It has some quite decent noise reduction features. But there are several specialty applications that major in noise reduction. If you post some (UNCOMPRESSED) samples, we might be better able to suggest how you might do it with Audition (if possible) or with some other special noise-reduction tool.

REMEMBER that it is ALWAYS better to record at a proper level than being forced to try to fix it after the fact. And be prepared that many situations simply cannot be saved even with the best editors and software.

Paul R Johnson
May 19th, 2013, 09:04 AM
Adobe Audition is an audio workstation, RX2 is a fairly expensive restoration type platform, designed to remove hiss, crackle, hum etc. Depending on your version of audition you may have some plugins that can remove noise to a degree - but the more noise removal, the greater the impact on your audio. So it's always a tradeoff. If the hiss is very annoying, then maybe a bit of graininess in the wanted audio is better than the hiss - only you can tell.
Advanced Noise Reduction in Audition CS5.5 | No Stupid Questions with Colin Smith | Adobe TV (http://tv.adobe.com/watch/no-stupid-questions-with-colin-smith/advanced-noise-reduction-in-audition-cs55/)
This explains how audition handles noise reduction.

Kathy Smith
May 19th, 2013, 09:18 AM
Audition is an general-purpose audio editing tool. It has some quite decent noise reduction features. But there are several specialty applications that major in noise reduction. If you post some (UNCOMPRESSED) samples, we might be better able to suggest how you might do it with Audition (if possible) or with some other special noise-reduction tool.

REMEMBER that it is ALWAYS better to record at a proper level than being forced to try to fix it after the fact. And be prepared that many situations simply cannot be saved even with the best editors and software.
Yes, getting it right in the first place is the way to go BUT I have lots of excuses about what went wrong but I won't get into this here. I will post the file. Thanks

Kathy Smith
May 19th, 2013, 09:21 AM
Adobe Audition is an audio workstation, RX2 is a fairly expensive restoration type platform, designed to remove hiss, crackle, hum etc. Depending on your version of audition you may have some plugins that can remove noise to a degree - but the more noise removal, the greater the impact on your audio. So it's always a tradeoff. If the hiss is very annoying, then maybe a bit of graininess in the wanted audio is better than the hiss - only you can tell.
Advanced Noise Reduction in Audition CS5.5 | No Stupid Questions with Colin Smith | Adobe TV (http://tv.adobe.com/watch/no-stupid-questions-with-colin-smith/advanced-noise-reduction-in-audition-cs55/)
This explains how audition handles noise reduction.
I have access to Audition CS6. I am looking to remove the background noise which gets loud because the audio levels were very low and I had to boost them.

Guy Caplin
May 19th, 2013, 09:34 AM
You might try Audacity: Audacity: Free Audio Editor and Recorder (http://audacity.sourceforge.net)

This is a free audio program and the audio noise cancelling effect is excellent. The best way to use it is to use a small amount of noise cancelling several times in succession, resampling the residual noise background each time. I always use this when shooting interviews in heavily air-conditioned rooms.

Kathy Smith
May 19th, 2013, 09:56 AM
I'll give it a try, thanks

Rick Reineke
May 19th, 2013, 11:59 AM
If the mic was not close to the sound source for instance a camera mounted mic (a common occurrence) NR or other post -processing will be of marginal use in bringing sound 'closer'.
Upload a sample file for non-speculative analysis.

Kathy Smith
May 19th, 2013, 12:58 PM
Here is a sample file https://www.dropbox.com/s/jjhlvzbky8sba1h/sample.wav

Battle Vaughan
May 19th, 2013, 01:48 PM
This doesn't seem to present a huge problem. There are a couple of good noise sampling places --- a pause early in the take and the long pause at the end, if you sample these and do noise reduction in two or three passes you can take the background out pretty easily.

I used Sony Sound Forge but Audacity and Audition also have very good nr tools, this isn't hard to do. 1. Work on a copy of the file, just in case. 2. Do some trials before you save the nr. 3. Work up to the final in two or three steps, don't try to nail all the noise on the first pass or you will probably end up damaging the part you want to keep.

I did take the very low - volume part at the start, make a selection of it and normalize it to -10dB to better match the rest of the take. Did this after the NR.

There is a lot of what I assume is the proximity effect from using a cardioid mike close up (bass boominess) which you can work on with equalization --pull down the150 hz and below a tad to even things out....

Kathy Smith
May 19th, 2013, 02:01 PM
This doesn't seem to present a huge problem. There are a couple of good noise sampling places --- a pause early in the take and the long pause at the end, if you sample these and do noise reduction in two or three passes you can take the background out pretty easily.

I used Sony Sound Forge but Audacity and Audition also have very good nr tools, this isn't hard to do. 1. Work on a copy of the file, just in case. 2. Do some trials before you save the nr. 3. Work up to the final in two or three steps, don't try to nail all the noise on the first pass or you will probably end up damaging the part you want to keep.

I did take the very low - volume part at the start, make a selection of it and normalize it to -10dB to better match the rest of the take. Did this after the NR.

There is a lot of what I assume is the proximity effect from using a cardioid mike close up (bass boominess) which you can work on with equalization --pull down the150 hz and below a tad to even things out....


Thanks so much Battle. This is very helpful. I feel better knowing that this is salvageable. I will try it with Audition.

Kathy Smith
May 19th, 2013, 02:02 PM
I have another file (much worse) that I will post tomorrow to get an opinion on how bad it is.

Battle Vaughan
May 19th, 2013, 02:03 PM
Hope it's some help. Play the sample I attached to my reply and see if it's on the right track for you....

Kathy Smith
May 19th, 2013, 02:10 PM
Yes, I played it. It sounds pretty good. A bit "boxy" on the beginning but I think I can play with it.

Battle Vaughan
May 19th, 2013, 02:36 PM
That's what I was talking about, why you might add eq. Attached file with the 150hz and lower cut by -6 dB

Kathy Smith
May 19th, 2013, 02:58 PM
Better, thanks!