Octave's

Posted: Fri Dec 21, 2007 11:05 pm

I saw a product demo that had an EQ plugin that would detect all the octaves associated with the particular octave that was trying to be removed.

Could someone explain how octaves work and why you would eq out the "other" octaves? Is there a method behind that?

Posted: Sat Dec 22, 2007 3:03 am

Halifaxsoundguy wrote:

I saw a product demo that had an EQ plugin that would detect all the octaves associated with the particular octave that was trying to be removed.

Could someone explain how octaves work and why you would eq out the "other" octaves? Is there a method behind that?

here's my guess:

most timbres have harmonics of sorts. these active harmonics are what help you establish what you are listening to (ie - your mothers voice versus your sisters, etc). some audio sources activate harmonics in rising octaves.

another case where you might consider this is in the field of live sound. many rooms ring at octaves of a fundamental wavelenght. for example, a room that "fits" 1 400Hz standing wave can fit 2x 800Hz waves, 4x 1.6kHz waves, 8x 3.2kHz waves, etc etc.

so notching out these octave harmonics is something that might be necessary anyways.

any one else want to correct me?

Posted: Sat Dec 22, 2007 4:55 am

i want to correct you mr. rockstar....but im not goin too!

Posted: Sat Dec 22, 2007 3:56 pm

Briefly explained, an octave is the space between one musical note and another either half it's frequency or double it's frequency.

To give you an example, if you pluck the top open string of a guitar with standard tuning this is an E note. If you move up and octave (12 frets) this is where the next E note is. This is still the same note but it is double the frequency of the open string E.

hope this helps;)

Posted: Sat Dec 22, 2007 5:56 pm

perhaps it's the context in which it's being used... but this sounds "funny"... but the info you've been given is acurate in that the harmonic series is based on even divisions of a freq and multiples (doubles and halfs) are the strongest... also a room that rings a given frq tends to ring at it's multiples so at a base level it might help some people to know where those "octaves" are...

Posted: Sat Dec 22, 2007 7:54 pm

What about for a recorded sound? If you have some mud at 200hz will you have issues at 150hz, 400Hz, 800Hz, 1.6K, 3.2K Etc, Etc?

Posted: Sat Dec 22, 2007 8:12 pm

possibly... but not likely IMO... unless your room is WAY outta wack... and you're experiencing room modes... the reason being that while the overtones are extremely important in terms of a sounds character they are'nt there in a proportion that would build up like this...

Posted: Sun Dec 23, 2007 12:48 am

Is it just me, or is the obvious answer:
Please post more info about the product of which you speak so that we might better know what we're talking about?

The only thing that comes to mind here is removing 60hz hum. Which will have a component at 120hz and 240hz.
If there is a plugin that will detect how far that particular sound extends (as well as it's volume), it might be interesting.

Posted: Sun Dec 23, 2007 9:26 am

I don't know the exact plugin, but it was with nuendo. The plugin was an eq that automatically found octaves of a frequency that was trying to be removed. I just wanted to know why you would do that. Thats new to me. I'm always looking for skills to have in my mixing trick bag.

Posted: Sun Dec 23, 2007 3:07 pm

natural wrote:

Is it just me, or is the obvious answer:
Please post more info about the product of which you speak so that we might better know what we're talking about?.

HEY buddy!!!!! if half trueths, innuendo, and speculation is good enough for the feds..... who are you to confuse me by bringing facts into it????

Posted: Sun Dec 23, 2007 3:58 pm

It's important to understand that it's not just a matter of octaves. It has more to do with the harmonic series than with just octaves, otherwise, each of the even multiples could be removed and the whole note and its residuals would be removed. (BTW, this is useful in removing 60Hz hum and other similar noises such as RF bleed from old TV tubes...)

The harmonic series goes something like this:

Fundamental
1 Octave up
1 Fifth up
1 4th up
1 major 3rd up
1 minor third up
1 smaller than minor third up
1 greater than major second up
1 major second up
1 slightly smaller than major second up
1 slightly larger than minor second
minor second...minor second...smaller than minor second and so on and so on ad infinitum.

You're welcome to do the math on this, but I'm afraid the "smaller than" and the "slightly larger than" statements will make that kinda hard.

The real question is, other than treating errant line or RF noises, what exactly would be the purpose of doing this since it would have profound (in a negative way) effects on most recordings (unless done specifically for effect...)

Cheers-

J.

Posted: Sun Dec 23, 2007 4:16 pm

Cucco wrote:

The harmonic series goes something like this:

Fundamental
1 Octave up
1 Fifth up
1 4th up
1 major 3rd up
1 minor third up
1 smaller than minor third up
1 greater than major second up
1 major second up
1 slightly smaller than major second up
1 slightly larger than minor second
minor second...minor second...smaller than minor second and so on and so on ad infinitum.
J.

hi jer... i find it interesting that you describe the overtone series this way... am i remebering correctly arent you a trumoet player????forinstance the second 8va you describe as a 4th from the previous which is true enough but is better understood as that *va relationship.... and then all those thirds and seconds... instead of the 3rd 5th b7th 8va 9th etc... oh well happy holidays man...

Posted: Mon Dec 24, 2007 4:02 pm

I'm starting to see by your examples that the use of this plugin would be for removing noise from a recording. So it may be safe to say its a dialog editing plugin since nuendo is primarily for post audio.

Posted: Mon Dec 24, 2007 4:07 pm

dementedchord wrote:

Cucco wrote:

The harmonic series goes something like this:

Fundamental
1 Octave up
1 Fifth up
1 4th up
1 major 3rd up
1 minor third up
1 smaller than minor third up
1 greater than major second up
1 major second up
1 slightly smaller than major second up
1 slightly larger than minor second
minor second...minor second...smaller than minor second and so on and so on ad infinitum.
J.

hi jer... i find it interesting that you describe the overtone series this way... am i remebering correctly arent you a trumoet player????forinstance the second 8va you describe as a 4th from the previous which is true enough but is better understood as that *va relationship.... and then all those thirds and seconds... instead of the 3rd 5th b7th 8va 9th etc... oh well happy holidays man...

Yeah, I was thinking from one note to the next, not from the fundamental.

Besides....horn player...not trumpet player. GRRR... Evil or Very Mad

(JK)

Posted: Mon Dec 24, 2007 4:32 pm

From the sound of things, I originally thought he might have been talking about Algorithmix's reNOVAtor. This is a spectral editor that will let you (in some cases, with isolated tones, etc.) not only hightlight the fundamental, but all of the related overtones. (Root, Octave, Fifth, and so on...)

Removing "octaves" per se isn't any way to tune a room or fix a problem, but it's always good to see what you're hearing.

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