Lord Smurf & all - How to remove rumble still remaining after noise removal

[jagabo]

Try a high pass filter with the cutoff set at 600 Hz, and rolloff 6 dB/octave. If that doesn't work try a sharper rolloff and/or a higher cutoff.

How do I do that in Audacity?

The High Pass filter. That is a brute force method. It will remove all low frequencies, not just 60 Hz and harmonics. I'm curious to see if makes any difference to you.

[VideoFanatic]

Didn't work. I think I'll just have to accept that it can't be done. Thanks to everyone for your help anyway.

[pandy]

"rumble" is not related to hum (not directly at least) but to way how audio is processed trough FFT - simply lower frequencies intermodulate other create this "rumble" or i think better know wobbling sound - when - noise profile is taken, lower part of spectrum irregularly modulate - in effect some frequencies appears then disappears (around threshold point) - this is why i say that noise profile from lossy compressed audio is not representative and very aggressive settings are not possible.
IMHO to denoise lossy compressed audio strategy without noise profile must be used (or short FFT and many noise profiles - perhaps some adaptive level etc).

As we talking about Audition - there is Hiss filter, preset High Hiss Reduction, mark Keep only noise, preview and try to set level where single tones harmonics will be not present (they sounds in a chirp - whistling way).
Once again after lossy compression audio is made from discrete frequencies, discrete levels of quantizations - all this is shaped by complex (more or less) model of human hearing system - there is no PCM audio, no noise profiles etc.

--
i think that "rumble" is created by complex room acoustic and human voices in background - they create sound texture that appears to be like noise - this is my point - how to distinguish between signal which appear to be like noise and real noise - only brain can do this - only brain can decide what is noise and what is not noise even if spectrum looks like noise - there no ready to use prescription how to denoise this audio.

[jagabo]

Rumble is incoherent low frequency noise. Hum is noise with a specific frequency (or frequencies) and its (their) harmonics.

[VideoFanatic]

Can any of you guys recommend a good forum or other sites to learn about audio editing (particularly Adobe Audition) as I think I have a lot to learn and I'm not sure videohelp.com is the best place to ask questions about that as most people here don't use Audition. Strangely the Adobe forum isn't much help!

[Cornucopia]

There are other forums that are Audio-only related, but I disagree with your assessment of this site. PLENTY of users here use Audition.

I do (though not exclusively).

However, I would also say that "learning about Audio Editing" is not best done in a forum (ANY forum). It's best done with hands-on teaching, tutorials, books/videos, instructional sites.
Forum like this will often include people like me who enjoy "educating in general", but that's usually in addition to or tangential to the main focus of "answering the specific question/problem at hand".

What do you want to learn?

Scott

[VideoFanatic]

Nobody who uses Adobe Audtion really answered my question in this thread about how to remove rumble. Would I be better off starting a new thread with the title "How to remove rumble in Adobe Audition?". Audio After Noise removal (rumble still present)

Do you know of any other forums which are good for discussing Audition?

I haven't seen any instructional videos or tutorials that helped me - if you know of any good sites with videos then please let me know. I would like to know how to remove rumble. Also how to remove hiss like this which seems to be an artifact caused by noise removal (this is rare).

I see things like the FFT filter and Hard Limiter but I have no idea how and why I would need to use them.

[pandy]

Nobody who uses Adobe Audtion really answered my question in this thread about how to remove rumble.

How to not add rumble - i try to say that by FFT incorrectly set you can introduce "rumbling" previously not existing.
Also i believe that in this particular case "rumble" are correlated with signal because they are created by FFT.

I would like to know how to remove rumble. Also how to remove hiss like this which seems to be an artifact caused by noise removal (this is rare).

Once again - how to not add "rumble" - use less aggressive FFT settings, verify used settings with your ears/brain, don't follow blindly settings, profiles, hear and adjust based on subjective perception noise.

I see things like the FFT filter and Hard Limiter but I have no idea how and why I would need to use them.

This audio doesn't need any hard limiter - use hiss reduction, take no profile, adjust level, mark keep noise and adjust to point when you don't hear tones correlated with audio itself - this will be extremely difficult because audio is after lossy compression and previous noise now is part of complex audio image - is no longer one level, level is variable (and quantized in non linear way), also frequency (or perhaps noise color) is correlated with audio.

[jagabo]

Nobody who uses Adobe Audtion really answered my question in this thread about how to remove rumble.

You don't have rumble. The fact that a high pass filter didn't remove the noise you hear indicates it's not rumble. Rumble is incoherent low frequency noise. Generate a 600 Hz sine wave in Audacity and see what a high pitch that is. Rumble would be at much lower frequencies.

[VideoFanatic]

This audio doesn't need any hard limiter - use hiss reduction, take no profile, adjust level, mark keep noise and adjust to point when you don't hear tones correlated with audio itself

Could you describe step by step as to how I would do that?

Pandy - When you were talking about FFT, are you referring to the FFT setting of the Noise Reduction menu? The default is 4096. I've used that on loads of other videos and the finished audio didn't have rumble. However a different wrestling season I'm working on now does have rumble which may be in the video already (I don't know because the hiss may be covering it up so I can't hear it). When I remove the hiss with my hiss sample, I can hear rumble. I tried a lower or higher FFT setting but it made no difference and I can still hear the rumble.

Jagabo - How do you know what the sound is if you said you can't hear it? Here's a screenshot of Adobe Audition in spectral view. The audio on the left is the unedited audio. The audio on the right is the rumble sample I use to remove the rumble noise. As you can see this IS low frequency.


[Attachment 14533 - Click to enlarge]

[budwzr]

Hey OP! Check out Ableton Live. A REAL DAW. Adobe sux, it's for noobs. Like Apple stuff.

No pro musicians use Adobe Audition. hahaha.

Sorry I couldn't fix your audio either, but I'm not an engineer, I'm an Artiste! hahaha.

[pandy]

Could you describe step by step as to how I would do that?

Effects -> Restoration -> Hiss Reduction -> Profile High Hiss Reduction -> mark ON Keep Only Hiss -> Preview -> Adjust Noise Floor level to point when you don't see on spectrum analyzer single frequencies and you don't hear tones modulated by useful audio - signal which remains is must be uncorrelated with useful audio (this part is extremely difficult and i warn you earlier - audio was lossy compressed and now it will be probably not possible to remove noise without adding new distortions. When you accept result, stop doing preview and unmark Keep Only Hiss (mark ON "Remove Hiss"), press OK.

Pandy - When you were talking about FFT, are you referring to the FFT setting of the Noise Reduction menu? The default is 4096. I've used that on loads of other videos and the finished audio didn't have rumble. However a different wrestling season I'm working on now does have rumble which may be in the video already (I don't know because the hiss may be covering it up so I can't hear it). When I remove the hiss with my hiss sample, I can hear rumble. I tried a lower or higher FFT setting but it made no difference and I can still hear the rumble.

I says FFT size is always tradeoff between frequency and time resolution - DFT, FFT, Wavelets are not miracle transformations - they have always pros and cons and they need to be used in a way to solve some problems without introducing to many new problems.

http://music.columbia.edu/cmc/musicandcomputers/chapter3/03_05.php
http://support.ircam.fr/docs/AudioSculpt/3.0/co/The%20Right%20FFT.html

You need to perform many experiments - and don't expect miracles - IMHO after lossy compression there is no chance to restore audio (in this case denoise). Always will be some trade off between noise and signal and artifacts.
Subtraction of noise with profile works only when color remains same as in profile - for lossy compressed audio noise level and noise color (spectrum) is variable and noise is no longer "white noise"

And once again rumble is effect probably created by denoising - sometimes it can be also related to way how audio is reproduced - search for "wow and flutter" distortion definition ( https://en.wikipedia.org/wiki/Wow_and_flutter_measurement ).

Sorry I couldn't fix your audio either, but I'm not an engineer, I'm an Artiste! hahaha.

https://it.wikipedia.org/wiki/Merda_d%27artista

[jagabo]

Jagabo - How do you know what the sound is if you said you can't hear it? Here's a screenshot of Adobe Audition in spectral view. The audio on the left is the unedited audio. The audio on the right is the rumble sample I use to remove the rumble noise. As you can see this IS low frequency.
[Attachment 14533 - Click to enlarge]

I know what elephants look like. I don't see any elephants in my office. I can say with reasonable certainty there are no elephants in my office.

The only significant low frequencies present in your sample are in the booms when the wrestlers are thumping the floor mat. Is that what you're talking about?

[ConverterCrazy]

"rumble" is not related to hum (not directly at least) but to way how audio is processed trough FFT - simply lower frequencies intermodulate other create this "rumble" or i think better know wobbling sound - when - noise profile is taken, lower part of spectrum irregularly modulate - in effect some frequencies appears then disappears (around threshold point) - this is why i say that noise profile from lossy compressed audio is not representative and very aggressive settings are not possible.
IMHO to denoise lossy compressed audio strategy without noise profile must be used (or short FFT and many noise profiles - perhaps some adaptive level etc).

As we talking about Audition - there is Hiss filter, preset High Hiss Reduction, mark Keep only noise, preview and try to set level where single tones harmonics will be not present (they sounds in a chirp - whistling way).
Once again after lossy compression audio is made from discrete frequencies, discrete levels of quantizations - all this is shaped by complex (more or less) model of human hearing system - there is no PCM audio, no noise profiles etc.

--
i think that "rumble" is created by complex room acoustic and human voices in background - they create sound texture that appears to be like noise - this is my point - how to distinguish between signal which appear to be like noise and real noise - only brain can do this - only brain can decide what is noise and what is not noise even if spectrum looks like noise - there no ready to use prescription how to denoise this audio.

I came for a solution to this 'rumble', but have to agree with you. The last paragraph says it all.

The solution may lie in using equalizer - tinkering with low frequency cuts in real-time in an audio editing tool like Ocenaudio (Portable version) – and going by the ear.

[lordsmurf]

The solution may lie in using equalizer - tinkering with low frequency cuts in real-time in an audio editing tool

In the past few years, since this thread, I've delved more into advanced Sound Forge usage. It's very powerful, almost rabbit-hole like, and it's rare that I can't restore even the ugliest of audio.