So basically i have all 4 jam packs, on my macbook pro, and it takes up alot of space
.. But i have an external harddrive, usb 2.0, could i put all the jam packs on it, and just plug it in when i need to use them?
Of course you can and it's a good idea too, considering the massive amount of room they'd be consuming on your internal HD.
This is what you need to do:
By default, the Loops are kept at two places;
YourUserAccount -> Library -> Audio -> Apple Loops &
YourUserAccount -> Library -> Application Support -> GarageBand -> Apple Loops
Have a look in these locations and when you find the one which has the Jam Packs, drag these folders to your External Drive. They will be copied now and when that's done drag the original folders onto your Desktop.
The next time you're using GarageBand (and now is a good time) and try to use any of the Jam Pack loops, GarageBand will display an error box saying it can't locate them and would you like to re-index your loops. Click Cancel.
Instead, navigate to your External HD, to the place where the Jam Packs are located and drag them into GarageBand's Loop Browser. You will see a dialogue box asking you if you would like to copy the loops to the Loops folder or keep the loops in their current location. What is important to this whole thing working is that you need to tell GarageBand to
keep the loops in their Current Location.
Now is a good time to put the operation to the test by selecting one of the Jam Packs from the Browser Loops Pop-Up Menu, choosing a sound then previewing it. If GarageBand can't play it and asks you to let it re-index the loops again, well let it do it this time and then test it out to see if it's all hunky dory.
Lastly, when you are sure everything is working perfectly, delete the original Loop folder/s you moved onto your Desktop.
That should be it and you've just freed up some valuable HD space on your internal too
.