if your talking about not using 3rd party plug-ins then try this...
1) Make a software instrument channel
2) Add some MIDI info (I like to tweak things in real time)
3) Loop it
4) Open up 'ES P' on a MIDI channel/software instrument
5) select a bass type sound 'Fat Square Bass' does the job.
6) and then tweak it so it looks like this:
http://i291.photobucket.com/albums/ll289/beatcreeplogic/es-pwobble-bass.jpg
hope the link works! (why don't apple sort it out so that they have an upload button!? I can't be bothered to do all the HTML coding... anyhow..)
7) Tweak things as you see fit:
i) The buttons on the left within es p take it up or down octaves
ii) You can tweak the sound wave patterns - making it more of a saw tooth, square etc
iii) Speed makes the worble faster or slower
iv) The higher the wah the more wobble (its more of a growl at the vib end)
v) freq - messing with the freq can make it sing!
vi) mess around with everything....!?!?
I think the key is with the adsr (attack, decay, sustain, release) - I usually have the attack quite slow/long when trying to make it worble.
hope this helps and sorry if ive waffled!!
