vocal processing?

[feverrayman]

i hope i posted this in the right catagory....any ways, i have been doing some thinking about a new project.

Im a huge fan of vocal processing, and would love to build my own vocal processor or modify one. being that i dont really have that much in the way of experiance with vocal processors, i was wondering if any one would know a good place to start? i was thinking of getting my hands on some old TC-helicon tech, but it still might not be worth spending the money, no matter how old the model is. so, any suggestions?
 
thanks for reading!

[feverrayman]

oh, one more thing, i was thinking about making something that would end up slightly similar to the TC-helicon E1, but more "wet" sounding

[Gordonjcp]

I don't really know what you're trying to get it to sound like.  What do you mean by "vocal processing"?  Compression?

[feverrayman]

I don't really know what you're trying to get it to sound like.  What do you mean by "vocal processing"?  Compression?

oh sorry about that! yeah i should be more specific. im trying to be able to modulate the shape and depth

[Circuitbenders]

oh sorry about that! yeah i should be more specific. im trying to be able to modulate the shape and depth

If anything thats less specific. Shape and depth? 

[feverrayman]

ah sorry, i dont have a very good way with words  hm how do i put this..... i was thinking of making something that had the proporties of a compressor,that has a fairly "wet" sound, that also has de-tuning proporties. sorry if that doesnt really make any sense haha im horrible with words 

[nochtanseenspecht]

i've had a digitech vocalist a while ago, its cheap and "wet"
didn't try to bend it, but i guess that would be fun

[feverrayman]

i've had a digitech vocalist a while ago, its cheap and "wet"
didn't try to bend it, but i guess that would be fun

thanks, ill look into it

[nochtanseenspecht]

i had the desktop version, there's a slider for "wet" 

actually it was fun on monophonic sources, could make cords etc..
on polyphonic sounds it was nasty at least in my ears, guess some folks here would love it 

[Gordonjcp]

A compressor is fairly easy.  Detuning effect is maybe harder.  Pitch shifting is done by what is basically a slight perversion of a digital echo circuit.  Instead of reading the sample from RAM then writing the new sample over it and moving onto the next one, you have a playback and a record pointer that can cycle around the delay RAM at different speeds.  So, if you shift the pitch up you read the delay line slightly faster than you write (with a glitch at the end because you've run out of samples), and if you shift the pitch down you read the delay line slightly slower (with a glitch because you've got samples left over).  This is not easy to build without dedicated DSP stuff.

You could do frequency shifting by using a pair of ring modulators, and using two different carriers somewhere above audio frequency.  This isn't especially easy to make either and *doesn't* do pitch shifting - it doesn't maintain the ratio between frequencies, it maintains the frequency difference.  So with a pitch shifter, two tones at 100 and 150Hz might shift up an octave to 200 and 300Hz but with a frequency shifter they might be 200 and 250Hz.  Weird clangy noises abound.

[Gordonjcp]

It's easier to show than say.  Here's a recording made on an SSB communications receiver of an AM shortwave station, as I tune across its frequency.  You can hear the carrier shift up and become a high-pitched tone.  At small levels of shift, it doesn't sound too "wrong".

http://www.gjcp.net/~gordonjcp/mp3s/9970kHz.ogg

[feverrayman]

thanks for all the help guys, this is really useful info!  i appreciate it