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frequency analysis

Posted: Sat Dec 06, 2008 3:58 am
by silver007
Is there some way I can get a good look at the frequency output of a file? I need to pinpoint where a certain instrument is falling within the range so I can 'equalize' it (I need to increase the volume of a certain instrument and decrease the volume of another). I found the Plot Spectrum under Analyze but got confused and it really didn't seem to tell me much. It also limited to 28 seconds. I need more of a blow-up of the big main spectrum. If I use Zoom, I just get a big foggy picture with no detail left.

Even if it's a different program suited better for that, that's ok, as long as the two programs see the frequency response generally the same.

Also, if anyone knows where some chart of instruments and their generally speaking frequency responses fall I'd appreciate that too.

Thanks!

Re: frequency analysis

Posted: Sat Dec 06, 2008 5:11 am
by kozikowski
The short answer to most of that is no.

<<<(I need to increase the volume of a certain instrument and decrease the volume of another).>>>

Musical instruments have an odd characteristic of occupying most of the audio spectrum even though their primary tones are localized. You would think that the tuba and the flute have no relation to each other at all, but if you want to suck the life and resonance out of a tuba performance, filter out the flute. Instruments closer together in pitch are much worse. So right away, if you don't have the original multi-track mix tapes/disks, it's pretty much hopeless.

<<<Is there some way I can get a good look at the frequency output of a file? >>>

The frequency analyzer is quite good, but it does take intense computing power to get all those lumps and bumps, so I'm betting you won't get much more of a selection than you got.

That said, you can change to Log Frequency and up the sample rate to 8192 or higher. Then grab the window size and pull larger and larger. It will keep giving you more and more detail the larger you go. Magnifiers need not apply. My screen is 1600 by 1200 and I can get resolutions down to the nearest 10 cycles if I fill the screen with the purple spectrum display.

Koz

Re: frequency analysis

Posted: Sun Dec 07, 2008 10:49 pm
by silver007
Musical instruments have an odd characteristic of occupying most of the audio spectrum even though their primary tones are localized.
LOL yeah unfortunately I'm becoming aware of that. I guess this means that even with a good display of the frequency output, I will still have a hard time picking out the freq I'm looking for. But, this is just sortof experimentation so I think I'll give your method a try and see if I can't play with the volume within any suspect frequencies I notice.

I think I'll also try something like Cool Edit or something. This could be addicting!

Re: frequency analysis

Posted: Mon Dec 08, 2008 1:42 am
by kozikowski
http://www.kozco.com/tech/audacity/piano_G1.jpg

That's a weapon's grade analysis of a concert grand piano G below middle C. One note.

Koz

Re: frequency analysis

Posted: Mon Dec 08, 2008 5:51 pm
by steve
kozikowski wrote:That's a weapon's grade analysis of a concert grand piano G
49Hz fundamental - bang in concert tuning, I never knew the military was involved :D