To find the GB drum sounds, follow this path:
Hard Drive/Library/Application Support/GarageBand/Instrument Library/Sampler/Sampler Files
in the Sampler Files folder, you'll see a whole bunch of folders with instrument names i.e. Alto Sax, Grand Piano, etc. What you're looking for is any folder with the word "kit" in it...Dance Kit, Hip Hop Kit, Jazz Kit, Percussion Kit, Pop Kit, Rock Kit, Techno Kit
Make copies of all of these "kit" folders. Take the copied folders and put them here:
User/Library/Application Support/iDrum
You don't specifically
have to do it this way, but I do because iDrum defaults to this folder when you want to select new drum sounds...easier than looking for them every time. I also put all the copied GB folders into one folder called "GarageBand Samples," just so I know what I'm using. Again, you technically don't
have to make copies or move anything...I just do it that way because it's easier for me.
for getting iDrum tracks into GB, what I do is this:
I DON'T open iDrum in GB...it's too slow, at least for me. I open iDrum as a stand-alone, and record my beats there. When I'm done, I export the iDrum file as a .aif file. Then I open GB, and simply drag the iDrum .aif file into the GB window so it comes in as a loop. You have to be careful to set the beats-per-minute/tempo in GB
exactly the same as you set it in iDrum, otherwise it gets all screwed up. A tip: Personally, I don't spend too much time trying to get the relative volume levels in iDrum
perfect (i.e. making sure the kick isn't too loud or the snare too low), I just get a good basic mix and then use the EQ in GB to put the finishing touches on it.
hope this helps
cheers