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bengomisthebomb
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Re: Finding the Exact Frequency of a Piece of Audio

Tue Jan 05, 2016 1:43 pm

Yep, still no timer...
 
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Eric Cardenas
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Re: Finding the Exact Frequency of a Piece of Audio

Tue Jan 05, 2016 2:00 pm

I replied on your other thread. Please keep the discussion there instead.
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bengomisthebomb
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Re: Finding the Exact Frequency of a Piece of Audio

Sun Jan 10, 2016 5:27 am

We would only ever select the full wavelength if we knew the signal was a constant pitch. If that were the case, we probably wouldn't need to do this exercise!

Since this selection is only one half of the wavelength, we need to double this time value to .012 seconds to determine the value in cycles per second (Hertz). Now open OSX's Calculator app and change the View preference to "Scientific"


I don't get this at all... How is it half a wave length? When clearly it's only about 1/12th of the full wave length?
 
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Eric Cardenas
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Re: Finding the Exact Frequency of a Piece of Audio

Sun Jan 10, 2016 5:56 am

Here's the definition of wave length:

Image

Where to do you get 1/12th from?
Eric Bradley Cardenas
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bengomisthebomb
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Re: Finding the Exact Frequency of a Piece of Audio

Sun Jan 10, 2016 7:42 am

Eric Cardenas wrote:
Here's the definition of wave length:

Image

Where to do you get 1/12th from?


Gee, thanks for all your help! He mentions that he had to double his 0.06 wave length because it's only 'half a wave length' + each wave in my kick is of different length, so therefore is my kick in lots of different keys?

Thanks for helping this n00b learn!
 
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Eric Cardenas
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Re: Finding the Exact Frequency of a Piece of Audio

Sun Jan 10, 2016 7:47 am

What you are looking for is the fundamental of the drum.
A signal can contain many overtones.
By looking at the valley of the wave with the largest amplitude you are using the loudest part for your calculations.
This isn't always the fundamental but it is a good place to start.
Eric Bradley Cardenas
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angelonyc
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Re: Finding the Exact Frequency of a Piece of Audio

Sat Mar 19, 2016 10:54 am

Speakers work by moving rapidly out/in to make a wave form.. So they start at a mid point (as 0 volts ) and then move out (as a + voltage, and in (as a - voltage), to make the the first cycle.. It is this pushing and pulling of cone which makes the sound. Once the cycle starts moving above 16 - 20 cycles a second we begin to discern a pitch.. Middle A is the waveform crossing 0 volts 440 times a second. Faster and slower waveform crossings either above 0 volts, or below 0 volts will color the pitch (harmonics), otherwise a perfectly symmetrical wave form (out/in) would be a sine. I believe you need to look at the plus and minus voltage of the wave form to determine it's pitch properly. If you look at the first wave form you'll notice the above 0 volts is shorter in duration, then the minus voltage.. So doubling the below 0 voltage, is not going to give you an accurate viewpoint (rather earing point) of waveform cycle..
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nayam
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Re: Finding the Exact Frequency of a Piece of Audio

Sat Aug 31, 2019 1:50 am

It is really easy and simple to do. Thanks for sharing.
 
favdave
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Re: Finding the Exact Frequency of a Piece of Audio

Mon May 17, 2021 6:09 pm

The internet is full of hatred and ignorance...and then I find a thread like this where someone spends their time helping other musicians to make music and it gives me hope!

Thanks so much for this. Now all the other kids on my block won't make fun of my for having kick drums that are out of tune!!!
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