Originally Posted by: hdoranThese responses are extremely helpful and I have learned a lot through the resources you posted and my own experimentation.

As a follow up, can anyone help me with the "magic frequencies" I am learning about. Does anyone have a good resource for how they tend to use them for the different instruments and, if possible, how you tend to use Garageband to achieve them and separate out competing sounds

EQ is probably the most powerful tool you have.

Along that line, learning how to use the Low-Pass Filter, High Pass Filter and simple EQing. The loaded EQ in Garageband AUGraphicEQ is pretty powerful so you don't need anything special.

After that, learning how to use Compression with finesse and a tiny amount reverb. These are your most powerful tools...

Oh, one last thing...Understanding how much the bass guitar supports the guitars in a mix. Many guitar players chronically under-mix the bass.