GarageBand is an entry-level digital-audio workstation for Mac. It is typically included for free with new computers. With it you can record, edit and mix your music using your computer. GarageBand also has post-production tools that enable you to modify the sound of your recordings. For example, if you don’t own an acoustic guitar but want to create a bright, acoustic guitar sound, you can record electric guitar and then adjust the frequency of the recording in GarageBand.
Connect a 1/4-inch jack cable to your guitar. Connect the other end to the “Input” jack on the audio interface. This is the device that connects your instruments to the computer. Don’t use any effects pedals when connecting to the interface; these enhance the characteristics of your guitar that distinguish it from acoustic. Essentially, they will make your guitar sound more electric.
Connect the audio interface to the Mac with either a USB or FireWire cable, depending on the make and model of the interface.
Click the GarageBand icon in the “Applications” folder to launch GarageBand.
Click “Track,” “New Track” and select “Real Instrument.”
Hit “Record” and play your guitar take. Pluck the strings gently to approximate the way you typically use an acoustic guitar.
Hit “Stop.” This stops GarageBand from recording and renders the recording as a sound-wave graphic on screen.
Double-click the header of the sound-wave graphic. This opens the “Track Info” pane.
Click “Edit” and select “Visual EQ.” This tool enables you to filter out selected frequencies from the guitar audio. The Visual EQ tool has a menu and a visual interface that features a curve superimposed on a grid. The curve represents the amplitude of the various frequencies in the recording.
Click “Default.” Select “Acoustic Guitar Clear.” This is an equalization setting that emulates the typical frequency characteristics of an acoustic guitar. Acoustic guitars are generally brighter than electrics, with less “punch” and bass. To make further adjustments to the frequency profile of the recording, move the frequency curve around to increase and decrease the prominence of the various frequencies. Once you hit a sweet spot that makes your guitar recording more acoustic-like, click the curve to set the selected frequency at the selected amplitude.
Turn the volume on your guitar down slightly to make the output lower. This creates a softer sound.