Heh heh heh. Ok. A little corny, but this does relate to something fantastic I just found out and I am itching to use it. Lets talk today about Multitrack Audio. What?
Wait a minte Woody, isn't stereo multitrack? Sure is. So is 4 track, 6 track, 8 track (and I'm not talking about that large cassette player in your dads 1976 AMC Pacer or 1980 Trans Am. No. The multitrack we're talking about here is the use of an audio track that holds more than one or two tracks. Confusing and possibly unimportant to anyone other than an audio engineer, but if you think about it, it may be handy!
So lets dig in. But first, I think I need to define a few things as I'mma gonna throw you a bunch of jargon. You know what jargon is. He's that character in Star Wars with the long floppy ears and the... Wait. No. That was Jar-Jar Binks. Bad character, nevermind. I'll skip over that.
Here's a list of the terms I might be using later:
DAW - Digital Audio Workstation. Its software that engineers or even us home studios use to produce a finished piece of audio work. Can be a music mix, voice and music, or voice only. Cool eh? There are a number of them. Adobe Audition, Studio One, Reaper (what I use), etc. All are great and most all have about the same capabilities, so I'll try not to be software specific.
Audio Project - Its like a work table where you place items, tracks, recordings, other audio from other sources in one "file" to work on them.
Mix - The final outcome. What you really want to send out to the customer, be it vocals, vocals and music, music only, etc.
Track - A recorded line in an audio project. Kinda like a track in a train station. Contains all the relevant recorded information in a linear manner. Voice Only would be a track. Snare Drums would be another. Bass would be a third. Overhead or room mics would capture room ambiance. These can be tracks, but don't always have to be.
Source - What picks up the sound and lays it down on a track via hardware of sorts. The mics under the snares would be listed as a source, which leads to...
Channel - The designation for that source. Mono is a channel, usually heard via channels 1 & 2 as you normally hear them over speakers or earbuds or something. Stereo. Well that needs no explanation. Then there are other channels that you can assign. They can have their own output channel (what you are able to hear) or they can be mixed (see above) to form a final or intermediate mix. In relation to a source, a source can be sent to a channel of the engineers choice. I can send the Snare source to channel 7 for instance. Then send channel 7 to the main left channel so I can hear it.
Mono - Self explanatory. Most microphones only record mono. Kinda like having only one ear.
Stereo - Again, self explanatory. Two channels - Right and Left. Its what you listen to when you put in your earbuds or listen in your car. One great example of the use of stereo is Dazed and Confused by Led Zeppelin. Try it. The stereo is fantastic!
Bus - basically its a track that can be used to mix down (combine) other tracks which has the advantage of being able to effect changes in a global manner. Which leads me to...
Effects (FX) - What you do to a track or part of a track to make it different. I use the term different here because you can make it better, worse (heh heh, no, not me), add weird sounds or change the sound like reverb, remove reverb, or just about anything you want. Kinda cool. Most DAWs can use FX on the fly - that is, they don't really change the audio until you want to (see below).
Raw/Processed Audio - Ok, two terms in one, but basically it means an audio track that has had FX applied or not. A lot of engineers or producers like to have unprocessed (raw) audio, especially for voice or vocals. That way, they can add, subtract, enhance, or otherwise change those parts. Processed audio is usually what we send unless asked for raw. We usually clean up the audio by using FX to drop low end rumbles or enhance high end sounds...or even get rid of breaths and those annoying S's. We can add delay, echo, change the pitch up or down, make ya sound creepy or me like a 10 year old girl (no joke. I did that).
Sends - Ok this one took me a while to figure out. Lets say you needed an extension cord to power your vacuum because the outlet near you was full. The cord would send power to your vacuum from another outlet. You've told that outlet you wanted to send the power in this manner via the extension cord. You've in effect routed power from one source to where you wanted it to go. Same here.
And now for the BIG term here (which is what its all about. Big Terms.)
Multitrack - A track, that can have 1, 2, 3, 4...24+ channels, each containing recorded information that can (not always) be used to mix a final product. How could this be important? We'll find out in a minute. But first, a word from our sponsor...
So the reason why I'm onto this today is because I watched a fantastic youtube video from Kenny Gioia. Yes, he's a Reaper DAW guy. But that not withstanding, the video really resonated with me and wanted me to learn about multitrack and how to possibly use it. Most DAWs will have this capability-or they should have it, so look for the equivalent. I'll try not to be Reaper-specific and use those general terms from above. You did read the definitions above, right???? Oh well, TL;DR. I get it.
Well. Moving right along. So from what I can see, we home producers (of our work) don't really concern ourselves with such matters. What is it and why would it affect us? Well, it wouldn't, so if you are bored by now, take a break and hit facebook or something. However, here's my answer, and its really kinda good.
Let's say you needed to send not only the finished product to a client or customer, but they wanted your working files to do some further edits on or perhaps needed to drop in some extra music or voice or files. Can't do that with a mixed version. Hard to separate it out. Ya really don't want to send them your files per se and if they want raw files...well, you might as well consider DIY home dentistry (pulling teeth... hello!) Plus, you'd have to send them individual files, labled and all, for EVERYTHING. Sorry. Ain't'a'gonna'happn'.
This is where making a multitrack can be handy. Make the multitrack, send that or make it available for them, send instrutions and voila! Now, it would be up to the engineer on the other end to separate them out, but if they're good, should be no issue.
Another advantage to multitracks is you can archive your work easier as one file. Not that you aren't going to archive the whole shootin' match (all the files you used), but you have one master file with all the tracks you need to reproduce the work if there ever was an "Ooooops" moment.
The trick with multitracks, or shall I say the issue is that when playing a multitrack file back, it usually only plays the first two channels. That's because, well, most people listen on something with two channels - stereo, which means you'll only hear the first two channels.
Now, I'm not going to explain how to make a multitrack as it would be Reaper specific, but most DAWs can make them. Again, if you really want to experiment, check out Kenny's channel and the tutorials he has for multichannel. They are amazing.
Below is an example of an 8-channel track. Note there are four parts, each with two channels that are combined into one track. If I were to render or produce this, it would be one, 8-channel file. The engineer would be able to look at it, assume each two channels were stereo and should be able to break them apart.
Now how I made these, well, its something you'll have to explore in your own DAW. For me, I created a test audio project and was able to take the individual tracks for each song (in this case) and route them to a mix bus. From that, I was able to combine them into one single track that was 8-channel. I didn't need to make that one 8-channel track, but for the purpose of illustration, I did.
Note also that under the red dot on the left, there is a gray or green box labeled "FX". The individual song tracks have no FX applied. Mainly because these shouldn't need them. But, if I wanted I could add FX to them individually or just on the mix bus (labeled multi-track). That way, I can apply a global effect on all the tracks at once. In some cases this is handy, no matter if you're making multitrack audio projects or not. Something to think about.
Note that the "multi-track" track does not have any audio in it. Its simply there as a mix bus to combine all the other tracks and channels. The last one labeled "multi-track - stem" is what I "rendered" to actually see or create a true file for the multitrack. In this case, there actually is a file written with all 8 channels.
You can do this with about anything, even mono tracks. They'll mainly play through stereo by default, but you can always send them or assign them to a particular stereo channel in a number of ways. And again, if you wanted to send this mix as a single file that can be broken out by an engineer, you can create this type file. You can turn off any FX and send any tracks such as voice/vocals as "raw audio".
So, if you want to experiment with this and think you may have a need for it, by all means use it. You will have to research this for your DAW of course, but experimenting is fun!