Sweeping Low Pass

Third party AU's with demos that have effects like this.

Camelspace.
http://www.camelaudio.com/camelspace.php
I use Camelspace often.

SFX machine
http://www.sfxmachine.com/

okimasa wrote:
Hello everyone! I'm new to the forums, but not to OS X!

Anyway, I was wondering if anyone knows how to do a sweeping low pass. I'm after an effect that is somewhat like the Automatic Filter, but only happens once. Like if I set the Automatic filter's mode to Down and the sweeping pass would only go "down" once and not repeat.

If this can't be done with Garageband's default effects, I'm up for good third party ones you know of (or maybe some Apple ones I didn't!)

From GB itself, you could try putting on an AUfilter (click open the Details disclosure triangle on the bottom of the info pane on the right, add the AUFilter, and then specify its parameters by clicking on the pencil icon to its right). Then, go back to your track on the left, and click on its disclosure triangle which opens up its automation curve options. The ones you just specified in the AUFilter will be available. Select them from the menu, and add an automation curve - click on the line to make dots, drag the dots up and down - to achieve what you want. You'd want a curve that would imitate the sweep. You may have to play around with it to figure out which parameter(s) will give you the effect you're looking for.

For more information about using automation curves, you could search for "curves" in the help menu.

If you're interested in checking out 3rd party options, in addition to WarriorAnt's suggestions, another one you might want to check out is Nitro from PSP (14 day free demo):

http://www.pspaudioware.com/