Noise removal

[rorser]

I am converting to digital, some reel to reel tapes of phonograph records. When using Audacity's Noise Removal Effect, I am copying and pasting 4 or 5, approx. five second selections of noise (found between tracks) to the end of the recording; then I select the 4--5 segments of noise and use them for Get Noise Profile; then select the whole recording and execute Noise Removal. Is this the best way to use this effect? Sometimes it seems that the noisier of the segments I have chosen to use as my profile are ignored.
Gratefully,
Richard

[kozikowski]

Noise in phonograph records is a specialized case and software has been written to make the process easier than using the generic tools.

http://forum.audacityteam.org/viewtopic.php?f=28&t=1994

Koz

[rorser]

I have already used Click Removal. I just was hoping someone could address the best way to get a noise profile when using Noise Remover (independent of the medium). Please see my original post.

[steve]

Try to get a noise sample that is typical of the noise that you want to remove. If the noise sample is too short, you can use the "Repeat" effect to make it longer. 5 seconds duration should be enough for the noise sample. Noise removal in Audacity 1.3.13 is usually better than Noise Removal in Audacity 1.2.

[billw58]

Try to find a "representative" sample of between-track noise and use that. Not knowing the details of how the Noise Removal effect captures the noise sample, I don't know what it would do if presented with several different noise samples strung together. Otherwise your workflow is correct.

Vinyl surface noise tends to have a "pink" or "brown" profile, with more energy in the lower frequencies than in the higher frequencies. The built-in Noise Removal effect in Audacity will have trouble with this type of profile. At the very least I'd recommend applying a high-pass filter with a rollover frequency of 20 Hz and a slope of 24 dB before capturing the noise profile and applying Noise Removal.

For more sophisticated vinyl restoration tools, see: http://www.clickrepair.net/

-- Bill

[rorser]

Try to find a "representative" sample of between-track noise and use that. Not knowing the details of how the Noise Removal effect captures the noise sample, I don't know what it would do if presented with several different noise samples strung together. Otherwise your workflow is correct.

Vinyl surface noise tends to have a "pink" or "brown" profile, with more energy in the lower frequencies than in the higher frequencies. The built-in Noise Removal effect in Audacity will have trouble with this type of profile. At the very least I'd recommend applying a high-pass filter with a rollover frequency of 20 Hz and a slope of 24 dB before capturing the noise profile and applying Noise Removal.

For more sophisticated vinyl restoration tools, see: http://www.clickrepair.net/

-- Bill

Thank you Bill,
Not knowing exactly what is "representative noise" I select 3--4 and use them together for the noise profile. I guess no one here knows any reason not to do it that way, so I guess I will just keep doing it that way.
Regarding using the high-pass filter, I assume that your suggestion still applies even though what I am converting to flac files went from original vinyl to reel-to-reel magnetic recordings which is the media I am actually now converting to digital (not the vinyl).

[rorser]

Noise in phonograph records is a specialized case and software has been written to make the process easier than using the generic tools.

http://forum.audacityteam.org/viewtopic.php?f=28&t=1994

Koz

Koz, If I really want to convert my reel-to-reel tapes, i have got to stick with the simple to use Audacity tools. Life is too short and there is too much good NEWER music out there to spend ages in this conversion of my ancient stuff.
It is always good to know the right way to do things though. Thanks, R

[rorser]

Try to get a noise sample that is typical of the noise that you want to remove. If the noise sample is too short, you can use the "Repeat" effect to make it longer. 5 seconds duration should be enough for the noise sample. Noise removal in Audacity 1.3.13 is usually better than Noise Removal in Audacity 1.2.

What I was asking was about using multiple samples of noise from between 3 or 4 tracks as my noise profile. See original msg.
Thank you,
R

[billw58]

Regarding using the high-pass filter, I assume that your suggestion still applies even though what I am converting to flac files went from original vinyl to reel-to-reel magnetic recordings which is the media I am actually now converting to digital (not the vinyl).

Well, the reel-to-reel may have rolled off the subsonic noise, and maybe not.

Although life is short, take a minute to do a Plot Spectrum of your noise profile, with Size = 16384 and Axis = Log frequency. If there's nothing below 20 Hz, we can probably assume that all your reel-to-reel recordings are like and you don't need to bother with the high-pass filter.

-- Bill

[rorser]

Well, it looks like the little sample of noise that applied the spectrum analysis to does have quite a bit below 20 Hz, but I will let you decide. Please see attachment. And, thank you very much for your help,
Richard