Why two waveforms/soundwaves Garageband acoustic guitar track

Oops, my previous post was cut off. Here is the full explanation

Regarding the waveforms, you are right. On waveform is a mono Audio Region, double waveform is a stereo Audio Region. If you record on an Audio Track that is set to a mono input in the Recording Source, it will record a mono Audio Region. If it is set to a stereo input, then it will create a stereo Audio Region.

Please note that the Recording Source is only important for recording part. You can drag stereo and mono Audio Regions around between Tracks because a Track itself is always "two track" aka "stereo" aka "left-right"

Remember that GarageBand distinguishes between three different types of audio files (indicated by their color code) There are a few things to pay attention to:

Joinging MIDI Regions will create just a bigger Region ("container") including all those MIDI Events inside that new Region (container). Joining Audio Regions is different. GarageBand performs a "bounce in place". It is like a mini export, mixing those Regions together. But this is only the first step. Now it takes that newly exported Audio File and re-imports it into the Project.

Now Remember: newly "recorded" Audio Regions are purple, imported Audio Regions are yellow. What happens during the join procedure is that your recorded (purple) Audio Region become imported Audio Region and therefore change their color to yellow.

Remember the difference between the three types of Audio Regions:

screenshot from my book "GarageBand 11 - How it Works"

You have to be aware of that little side effect of the join process. Yellow Audio Regions cannot have a Follow Pitch feature anymore. This is the checkbox in the Track Editor "Follow Tempo & Pitch". Purple Regions can follow both your Project's Tempo and Key (Pitch), similar to Apple Loops. Yellow Regions can follow the Tempo but not the Key of your Project!

Hope that helps

Edgar Rothermich

http://DingDingMusic.com/Manuals

'I may receive some form of compensation, financial or otherwise, from my recommendation or link.'

Edgar wrote:

Please note that the Recording Source is only important for recording part. You can drag stereo and mono Audio Regions around between Tracks because a Track itself is always "two track" aka "stereo" aka "left-right"

Actually I have to correct myself on that one because it is a little bit more complicated under the hood (strange I can't edit my own forum posts anymore, is that feature gone?)

Regarding mono (one channel) and stereo (two channel), a Track in GarageBand has has to be looked at on three stages in the signal flow of the Track.

Stage 1: Input Source of the Track

The input is always determined by the Input Source selection. If you select a one channel Audio Device then the recorded Audio Region will be mono (1-channel, single waveform). If you select a single channel of a multi-channel Audio Device (2 or more channels), then the recorded Audio Region will also be mono. If you select the stereo channel of an Audio Device, then the recorded Audio Region will stereo (2-channel, double waveform)

Stage 2: Playback of the Audio Region

You can place a mono Audio Region or a stereo Audio Region on an Audio Track. But here is the important part. The setting in the Input Source (Track Info window) affects the playback. A mono Region will be played back in mono (the same signal coming out of the left and right speaker. If you have a stereo Audio Region and selected a stereo Input Source, then the Audio Region will be played back in stereo. However, and this is potentially very dangerous, if have a stereo Audio Region and have set the Track to a mono Input Source, then any stereo Audio Region wille be played back in mono. That means it is "summed together", left channel will play through the left-and-right channel of the Track and the right channel of the Audio Region will also play through left-and-right channel of the Track.

Stage 3: Output of the Track

The output of a Track always has two channels (left, right), routed to the stereo master bus. If the Audio Region on a Track "sounds mono" or "sounds stereo" depends on whatever happens in stage 1 and 2. And also don't forget the Master Effects. Adding Master Reverb to a mono signal will "widen" the signal to sound stereo.

Hope that clarifies it

Edgar Rothermich

http://DingDingMusic.com/Manuals

'I may receive some form of compensation, financial or otherwise, from my recommendation or link.'

Regarding the waveforms, you are right. On waveform is a mono Audio Region, double waveform is a stereo Audio Region. If you record on an Audio Track that is set to a mono input in the Recording Source, it will record a mono Audio Region. If it is set to a stereo input, then it will create a stereo Audio Region.

Please note that the Recording Source is only important for recording part. You can drag stereo and mono Audio Regions around between Tracks because a Track itself is always "two track" aka "stereo" aka "left-right"