Tutorial - Multi-track Overdubbing
- Ed 27Apr12: Should the intro be in an intro div?
- Bill 28Apr 12: I don't like the note div inside the intro div, so I'd vote to return it to the previous format.
- Ed 27Apr12: checked/fixed spelling & grammar
- Ed 27Apr12: checked/fixed links & added spans
- Bill 28Apr12: Koz loves to use the word 'show' to mean "mix" or "signal". I've seen users on the forum confused by this. I suggest we expunge "show" from the text and substitute something more conventional.
Introduction
This tutorial describes a method of creating a multiple sound track overdubbing session using Audacity. You record one track then play it back and add a second track against it: drums, guitar, voice, etc. repeat as needed.
With the methods described here you will be able to hear a mix of your live recording and the previous tracks simultaneously in your headphones. Live monitoring is often unavailable (or you hear yourself in the headphones after a delay) without hardware designed for this purpose.
The procedure is similar for any USB audio adapter, USB microphone or mixer providing that it has a headphone output and some way to mix the live signal with the computer playback signal and present that mix at the headphone output.
If your USB microphone, USB audio adapter or mixer does not have a headphone output you should follow the advice in the Audacity Wiki Overdubbing using your computer's on-board sound card using the hardware you have on hand. It is strongly recommended that you do not use your computer's built-in microphone.
Advice on connecting and testing several specific hardware combinations are available at Recording Multi-track Overdubs in the Wiki.
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If you have not yet made a recording and played it back using Audacity and your selected hardware, please read our First Recording tutorial. |
- Bill 28Apr12: This can also be done using a USB mixer or conventional analog mixer, but the connections are more complicated. USB "sound cards" (external USB audio adapters such as the UCA-222 or UCA-202), the Samson mic and Shure mic/USB adapter that Koz originally documented made it easy to mix playback of the previous tracks with the live sound. Using an analog mixer with a PC that has a line input will work but routing the playback to the headphones can be tricky; each brand seems to have its own way of doing this, and naive users are likely to stumble at this step.
My point is that the above advice implies that the methods listed are the only ones that work, which is not true. - Bill 29Apr12: Edited the sections above and below to make it clear that several hardware configurations will work.
Hardware
You will need hardware that allows you to:
- Get sound into the computer
- Listen without a delay to the sound going into the computer (the live sound)
- Listen to the previously-recording tracks simultaneously with the live sound
Hardware that will accomplish this includes:
- A USB audio adapter
- A USB microphone
- A conventional analog microphone plugged into an external USB adapter that includes a microphone pre-amp
- A conventional analog mixer
- A USB mixer
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In every case the device must include the ability to mix the live sound with the previously-recorded tracks and present that mix at a headphone output jack. Most USB microphones do not include this capability. |
Almost any Windows, Mac or Linux machine with fast enough USB and good storage can be used. You will need headphones or earbuds. If you require cranium-crushing headphone volume you may need a headphone amplifier. You must get the headphone sound from the USB audio adapter, output on the USB mic or headphone jack on the mixer, not from the computer headphone output. Headphone monitoring is good. Live microphones and speakers in the same room is a recipe for feedback.
- Bill 29Apr 12: I think this section is made redundant after the edits I just made to the in the Hardware section, above.
An external USB soundcard or adapter has three jobs:
- It converts the mixer's stereo analog signal to digital and sends it down the USB cable for recording.
- It converts the USB digital signal from the computer back to stereo analog so you can listen to it.
- It has an internal headphone mixer and mixes your existing track playback with your new, live performance so you can listen to both.
A USB microphone operates similarly; it is effectively a microphone with a built-USB adapter. Some USB microphones provide all three functions; most only provide the first two.
First recording
First, make a simple recording with no overdubbing or other fancy tricks; your system must work correctly for simple recording and playback before we go further.
- Bill 29Apr12: With the above edit, I think everything below here in this section, except the last two paragraphs, can go.
The discussion in the last two paragraphs demonstrates that you can play back something in Audacity while simultaneously hearing the live sound.
Configure your audio capture device so that playback from Audacity and monitoring of the input are both enabled and for the correct mode mono or stereo; this is device (and often platform) specific so it is hard to give specific advice here. For detailed specific configuations see Recording Multi-track Overdubs in the wiki.
- Peter 28Apr12: Ah, but the Audacity convention is to refer to the "Audacity Wiki" with a capitalized W - see the SF site and indeed the Wiki homepage. Actually this is a useful convention as it enables us to distinguish between wikis in general (of which the manual is one) and "The Wiki". Certainly this is the convention I use ... :-)>
Click once anywhere inside the recording meter (the one with the mic icon) to put the meter into monitor mode; this will display the microphone's sound level even when not recording. This may fail on some Linux machines using Jack.
Set your device to monitor and adjust the gain controls.
Play a record, an instrument, or sing through the microphone; don't peak much over -10 to -6 on Audacity's recording meter. You can fix low levels later but you cannot fix overloading, smashing, and clipping (meters too far to the right). You should be able to hear your performance in the headphones. Adjust the headphone volume control as needed for comfortable listening.
Click the Record button 
in the Transport toolbar.; Audacity will take a moment to configure itself and start recording. The blue waves will start to crawl left to right as you perform. Play or sing a simple song that you can use for rhythm and timing tests later.
Click the Stop button 
then press Home and then click the Play button 
to hear the track you have just made. You should hear the track in your headphones. While listening, if you tap or scratch the microphone, you can hear the scratching/tapping too.
This demonstrates what you will hear during the overdub sessions; any combination of existing tracks will play in your headphones in addition to your live voice or instrument, allowing you to play along with the existing tracks.
While listening to the playback of your test recording, talk into the microphone or play your instrument. You should be able to year your voice or instrument along with the playback. This demonstrates what you will hear during the overdub sessions; any combination of existing tracks will play in your headphones in addition to your live voice or intrument, allowing you to play along with the existing tracks.
If you cannot hear your live voice or instrument simultaneously with the playback you are not ready to begin overdubbing. This tutorial cannot cover every possible hardware configuration. If you need help, post a message on the Audacity Forum.
Setting the recording latency
Latency refers to the delay between the time the audio enters the computer and the time Audacity is able to record it to a track. For example, if you are recording a keyboard track, latency is the delay between the time you strike a key and the time that note is recorded.
For instructions on how to adjust the latency see the Latency Test page in the manual.
Performance
Choose (you don't need to save any of your tests). You are ready for your first overdubbing session.
Choose .
Confirm the following settings in the Transport menu:
- Overdub (on/off) is checked
- Software Playthough (on/off) is not checked
The first recording can be whatever you're planning to use as a base, backing track, guide or rhythm track. It can be anything including a which can be adjusted with its control panel for rhythm and composition; it could be music from a rhythm and chord machine playing through a mixer.
If you are not using Audacity's Click Track, be sure to record a lead-in—a non-musical rhythmical clue before the music starts which warns you of the imminent start. In a live band this would be the drummer or lead guitar count-in. You could use a synthesizer's rhythm stops or you can perform several rim shots into the microphone to establish the rhythm before the first note; tapping on the table with a pencil also works. You can edit it out later in post-production so nobody else will hear it.
Click the Stop button when you have recorded a sufficiently-long reference track then press the Home key.
Get ready to record your first real track, then click the Record button . You should hear your live performance and reference track playback in your headphone mix as a guide. Repeat for as many tracks as required.
The and buttons to the left of each track are valuable in overdubbing. Solo causes only that track to play and Mute turns that track off. Solo has options that can be set in Preferences. The gain control in the Track Control Panel to the left of each waveform controls the playback volume of that track—it affects the headphone mix.
When you get to a stopping point click the Stop button then choose to save your project. As you progress, you should save a new Project periodically with a slightly different filename. A good recommendation is to use ISO date and time for the file names or the start of the file names; refrain from using slash marks or other punctuation marks in a file name.
ISO Date and time
201110011500.aup -- that represents year: 2011, month: October (month 10), day: 01, time: 1500hrs.
Then save a new version of the song about every twenty minutes:
201110011520.aup
201110011545.aup
201110011602.aup
Do not go weeks with one Project and file name, and never cover up or record over existing work. If anything happened to that one Project, your project would be ruined and could nullify weeks of work. Think of what would happen if the lights went out right now, the computer ground to a halt and you were forced to use the last known good version of the show.
- Bill 29Apr12: I have always had a problem with statements like the one below. It seems we are dissing our own software. Also it is mixing three issues; a) the need for backups, b) the loss of Undo history on close and re-open and c) the fact that you must export to WAV, AIF, MP3 in order to use the resulting project for other purposes. The advice does nothing to preserve Undo history, so I don't know why it is even mentioned - I think it's just one of Koz's hobby horses.
Flipped the existing text into this note and put my preferred text in place.
Audacity Projects are not a good format for archive or playback outside Audacity and they do not save the UNDO history; therefore export to 32-bit WAV for archive and 16-bit WAV for Music CD, or MP3 for internet delivery and e-mail. Do not do production in MP3. You may need to adjust the volumes and levels of the show so the Export doesn't overload.
For extra safety it is good practice to periodically back up your project versions to a DVD-R or external hard drive for archive purposes. Remember that it is important to keep the AUP file and the _data folder together. One way to make sure of this is to create a zip archive of the AUP file and _data folder. In the unlikely event that the Audacity project is corrupted or your hard drive crashes you will be able to recover your work.
Note that Audacity projects cannot be played in computer media players nor burned to audio CDs. Export your project as 16-bit WAV or AIF for burning to a CD, or to MP3 for email or internet delivery. See Mixing for advice on doing the final mix of your project.
- Bill 29Apr12: I don't know why this is here.
All of the Audacity editing, filtering, and effects tools are available for each track or any combination of tracks before or after you sing/play, but not during; Audacity will not apply filters and effects in real time.
Troubleshooting
- Bill 28Apr12: Changed the box to 'Advice' from 'Alert'. It is not a "don't do this!" message. Also slightly edited the text to make it clear that it is your live sound that will be delayed if you plug the headphones into the computer instead of the USB device.
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- How much hard disk space do you have available? If your only experience with computer files is with spreadsheets, e-mail or pictures live audio (and video) production will stun you with the amount of disk space it consumes. With high quality overdubbing, project files and folders get big in a hurry; with periodic saving of version of a project (as detailed above), a project can get seriously large.
- Ed 27Apr12: "with periodic saving, a project can get very"
here we use "project" (note it is not capped--that is good) generically but in Audacity we have a very specific definition of "Project" (and often do not Cap it when we refer to an Audacity Project--even though--IMVHO--we should). I am trying to come up with a synonym for "project" (the generic concept) which we may use here (and elsewhere) but my feeble brain is stalled!
- Communications features on newer Windows machines can cause unwanted changes in recorded volume or make the recording sound tinkly and/or hollow; see this FAQ.
- Always ensure that you are directly connected to a USB port on your computer. Connecting through a hub is likely to cause audio drop-outs.
- Except in rare circumstances, you can't plug a stereo analog sound mixer directly into a Windows laptop for recording. Mic-in (many times a pink port) is mono, not stereo, and too sensitive for the mixer. An external USB audio adapter neatly gets around that problem even if you're not planning overdubbing or complex production.
Links
|< Tutorial: Recording Multi-track Overdubs
Ed 27Apr12: Did I miss something or is this a wiki convention...recently, in a few places, I have seen:
|< link-text
and wonder if the vertical-bar+left-angle-bracket is a Connie approved style for prefacing links?
- Peter 4Dec12: It's a Gale-approved style.
