getting correct pitches out of the emu...
Posted: Sun Apr 27, 2003 5:28 amokay, for those of you who have used the tone generating tip, and then discovered that you more complex sounds don't seem to work, this is the reason.
oh and this is just the start of something i plan on releasing to, this is being the first part of my, research if you will, into this subject. as most of you know i have no synth of my own and so i am using my emu and the test tones to make sounds. anyway
here we go
let a stand for the first wave's hz.
let b stand for the second wave's hz.
and so on...
let w stand for the number of waves used in creating your patch.
and here is your equation...
a+b/w
okay now i will prove this equation's truth...
two sine waves on top of each other at 440 hz, both being the same you would get this
440+440/2=440
simple huh, now lets get a bit complicated...
two sines: one at 300, one at 500...
300+500/2=400
it is almost a A4
now if you need a visual proof, what you can do is take your sine waves record them and keep them seperated. so basicaully what you will have is your first track be at 300 hz, and the second track being your 500 hz sine...
then make a track with these two on top of each other, making sure the waves all move upward... you will get a strange looking wave as the sum of the two...
okay now count three cycles on the one you know that is 300hz. that length is what is known as a centisecond... 1/100 of a second. now compare that distance with the 500 hz sine, you will discover that there will be five cycles in that same length of time..
remember, one cycle is equal to three crosses of the origin (kind of hard to explain with out pictures) and also remember the the begainning of the wave is 1, and also remember when you count out to the third crossing, that will be the first of the next cycle...
now you look at the wave that you created by combining the two sines, you should find that you will count out four cycles in the same length of time as the other two. thus the frequency is 400. if you guys make this wave, there is a section were the wave will only seem to touch the orgin, that does count as a crossing.
now what else you can do with this, is if you get a sample of a synth from some one, you can use that length and see how many cycles are in that then you will be sure of what the pitch is. this will be good for those of use who haven't spent time with proper ear training. and one more thing befor i go...
if you make a triad using middle c as your root, making a major triad, using the tonic, mediant, and dominate interval, your over all frequency will be:
261.63+329.63+392.00/3=327.75333333 which makes the over all pitch about E.
just and interesting observation...
now what i need to do is figure out how much the fine and course tunes sections actually adjust the frequency...
i hope this helps you guys out if anyone is making there own tones like i am.
like i said i am going to get more that will be alot more useful soon, i hope :)
oh and this is just the start of something i plan on releasing to, this is being the first part of my, research if you will, into this subject. as most of you know i have no synth of my own and so i am using my emu and the test tones to make sounds. anyway
here we go
let a stand for the first wave's hz.
let b stand for the second wave's hz.
and so on...
let w stand for the number of waves used in creating your patch.
and here is your equation...
a+b/w
okay now i will prove this equation's truth...
two sine waves on top of each other at 440 hz, both being the same you would get this
440+440/2=440
simple huh, now lets get a bit complicated...
two sines: one at 300, one at 500...
300+500/2=400
it is almost a A4
now if you need a visual proof, what you can do is take your sine waves record them and keep them seperated. so basicaully what you will have is your first track be at 300 hz, and the second track being your 500 hz sine...
then make a track with these two on top of each other, making sure the waves all move upward... you will get a strange looking wave as the sum of the two...
okay now count three cycles on the one you know that is 300hz. that length is what is known as a centisecond... 1/100 of a second. now compare that distance with the 500 hz sine, you will discover that there will be five cycles in that same length of time..
remember, one cycle is equal to three crosses of the origin (kind of hard to explain with out pictures) and also remember the the begainning of the wave is 1, and also remember when you count out to the third crossing, that will be the first of the next cycle...
now you look at the wave that you created by combining the two sines, you should find that you will count out four cycles in the same length of time as the other two. thus the frequency is 400. if you guys make this wave, there is a section were the wave will only seem to touch the orgin, that does count as a crossing.
now what else you can do with this, is if you get a sample of a synth from some one, you can use that length and see how many cycles are in that then you will be sure of what the pitch is. this will be good for those of use who haven't spent time with proper ear training. and one more thing befor i go...
if you make a triad using middle c as your root, making a major triad, using the tonic, mediant, and dominate interval, your over all frequency will be:
261.63+329.63+392.00/3=327.75333333 which makes the over all pitch about E.
just and interesting observation...
now what i need to do is figure out how much the fine and course tunes sections actually adjust the frequency...
i hope this helps you guys out if anyone is making there own tones like i am.
like i said i am going to get more that will be alot more useful soon, i hope :)