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Last edited by jagabo; 1st Nov 2012 at 15:09. Reason: typo
Didn't work. I think I'll just have to accept that it can't be done. Thanks to everyone for your help anyway.
"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.
Last edited by pandy; 2nd Nov 2012 at 06:34.
Rumble is incoherent low frequency noise. Hum is noise with a specific frequency (or frequencies) and its (their) harmonics.
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!
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?
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.
Also i believe that in this particular case "rumble" are correlated with signal because they are created by FFT.
Audacity and see what a high pitch that is. Rumble would be at much lower frequencies.
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]
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.
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 ).
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?
Last edited by jagabo; 5th Nov 2012 at 06:16.
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.Sword is no substitute for kitchen-knife.
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.