Sep 07

Introduction To Audacity

Audacity - Thumbnail

Several months ago, I wrote an article discussing the basics of setting up a home studio for the first time. I gave quick rundown of the primary hardware such as a soundcard, cables, and the guitar setup. I also briefly mentioned some software packages that could be used on your computer to capture and edit your music. This article is the first of several to help get you get started with a few recording packages. Today we are going to look at Audacity.

Audacity is a free to download, open source application available from the Sourceforge page here: http://audacity.sourceforge.net. For the purposes of this tutorial, we are using the latest stable (non-beta) version 1.2.4 and running it under the Windows XP SP2 Operating system. One of the other great things about Audacity, apart from being free and only 2.3MB -- is that you can download the software for Windows, Linux and Mac.

So lets get started. I am assuming firstly that you have a guitar and then either an amplifier or an effects pedal. If you need to plug the guitar directly into the computer, you should use something called a DI (direct input) box. These are fairly cheap, but don’t worry if you don’t have one. Here are a number of ways to connect the guitar up:

  • Connect the guitar directly to the computer soundcard
  • Connect the guitar via a DI box into the computer soundcard line in.
  • Connect the guitar up to your amp and then use the line out, or the headphone out, and connect this to the computer soundcard line in.
  • Connect the guitar to your effects pedal and then into the computer soundcard line in.
  • Connect the guitar to your amplifier, and then connect a microphone up to your soundcard and place this microphone up to the amplifier.
  • Connect the guitar into an audio interface and then connect this via USB or firewire to your computer.

This is by no means a full list of all the possible options, but it should give you the general idea. If you decide to use a microphone, you will either need a 6.5mm (1/4″) to 3.5mm (1/8″) adapter, or in the case of an XLR type mic connection (on pretty much all microphones) you will need some sort of amplifier with a line out. The final option is to connect the mic to an audio interface with a USB connection.

Once you are happy that the sound can be recorded, we can start by installing the Audacity software. Double click the .exe file and follow the instructions. It’s pretty simple as there are no configuration options other than where you wish to install the software.

Audacity - Setup

At the end of the setup, you don’t need to restart the computer (phew!) but can run Audacity right away. The screenshot below is what you will see.

Audacity - Main Interface

Before we pick up the guitar and nail out some crushing riffs -- we are going to look at the layout and tools that Audacity provides. I assume you will know the top line of words: File, Edit, View etc etc is known as the menu bar, and the buttons and other graphical controls below this are on what is known as the toolbar. The menu bar will contain text links to pretty much all features and commands of the software. The toolbar contains buttons that allow for quick access to the common actions such as play and record. In the top left corner of the screen, under the File, Edit and View menus, we have a selection of editing an manipulation tools.

Audacity - Tools 1

By default, the Selection Toolis selected. This looks like the letter I. To its right (with a blue line between 2 arrowheads) is the Envelope Tool. To the right again is a pencil which is known as the Draw Tool. Below the Selection Tool is a magnifying glass, and this is the Zoom Tool. To the right is a double ended arrow -- this is the Time Shift Tool. Finally, the star at the end enabled the Multi Tool Mode.

To the right of these are the control buttons.

Audacity - Buttons

Left to right these are: Skip to start, Play, Record, Pause, Stop and Skip to End. Simply enough, they allow you to move around a track just as you would do with a normal tape recorder.

Before we continue, I must make a note about mp3 files. MP3 is the MPEG-1 Layer 3 audio file. Because the algorithm (the computer code calculations) to encode or create MP3 files is patented, any software including this capability have to pay a fee to include it. What this in turn means to the end user (i.e. you and I) is that the software would no longer be free! What you need to do to get around this, is to download the freely available LAME encoder .dll file (or the so file for Linux / Unix, or the lib file for Mac) and tell Audacity to use this.

You can grab the correct files from the LAME MP3 Encoder website.

The first time you try to use Audacity to export a track to an mp3 file, it will warn you and then ask you for the file.

Audacity - Warning

Just browse and select the lame_enc.dll file and the file will be encoded and exported as normal.

Audacity - LAME

As the message says -- you will only have to do this once, and not each time you wish to export to the mp3 file format.

So, if you have got this far with no problems -- you should have audacity opened and ready to record, and your guitar should be plugged in. We’re now going to verify that we can record the sound properly by setting up the Audacity inputs.

Click Edit, and then from the menu select Preferences. This opens the Audacity Preferences window, and the Audio I/O (Input / Output) tab is selected. Here you can set the input (recording) and output (playback) device. I won’t be able to give you a specific option for each because there are so many different soundcards and audio setups. You will have to select the right device yourself.

Audacity - Preferences

In the two screenshots below, I have several options for both input and output devices. The playback device defaults to the Microsoft Sound Mapper, which is a sort of basic audio device. The NVIDIA nForce Audio is my onboard soundcard, the Bluetooth devices can be ignored, and finally the BCA2000 is my external audio interface -- and the device that I will select to playback sound.

Audacity - Preferences - Playback

Audacity - Preferences - Recording

The Recording devices are similar, a Microsoft device, my webcam microphone, the two Bluetooth devices (ignore these) and finally, the audio interface. Because the Behringer BCA2000 is my main audio device for recording use -- I will use this for both recording and playback.

The channels dropdown box will let you select the number of tracks to record from the chosen recording device. If you have a single microphone post selected (like the line in or mic in port on a PC soundcard) this should be set to 1 (Mono). The checkbox to play other tracks whilst recording the new one is useful for playing along to a drum or bass track to keep in time. If you do select this, the performance of your computer may suffer as it requires more CPU power.

The next tab is called “Quality” and requires you to simply select a sample rate and sample format. The defaults are fine (44100Hz and 32-bit float) as are the remaining options).

The final tab that needs attention is the File Formats. This defines the quality and type of file that you will create during the recording and editing process.

Audacity - File Formats

When you import uncompress audio you have 2 options. “Make a copy of the original before editing” means that a copy of the file is made by Audacity and this is placed in the project folder. The second way “Read directly from the original file” just references the original file, and only edits are saved in the project folder. The original file isn’t altered, but is only used for playback where there have been no edits on the track.

The advantage of choosing to make a copy of the original is that you avoid trouble, should anything in the original file change. For example, should you accidentally delete the original file, you’re lost.

You have to make up your mind before you start a project. Choose to make a copy of all imported files, and you’ll use more space on your hard disk(s), but it will be easier to back up the project too, because all files that have anything to do with your project will be in the project data directory

WAV is the default uncompressed audio format on Windows, and is supported on almost all computer systems. It can also be lightly compressed (about 4:1) using the ADPCM codec, but this is less widely supported on non-windows platforms. Audacity can read and write this format, including ADPCM on all platforms.

AIFF is the default uncompressed audio format on the Macintosh, and it is supported by most computer systems, but it is not quite as common as the WAV format. Audacity can read and write this format. The high end software package Cubase SX uses AIFF format, and I have changed mine from the default format setting of WAV to AIFF, but either is fine.

I also changed my MP3 Export bit rate from the 128kbps (shown in the above screenshot) up to 192kbps.


When the settings are correct, click OK and return to the main Audacity window. We will now create a new project. So that you can keep track of the audio files for a particular song or recording, you need to click File and then Save As and then select a destination for your files.

I personally have a folder for audio recording, and then each new track is in a folder within that. It is also kept on a separate hard drive along with my video editing so it’s fairly safe. I suggest you try and get hold of a new hard drive to store your audio recordings, or at least make a new folder to save the projects into, because recording audio can take up a lot of space. My current usage is a comparatively small 13GB.

To add a new audio track to your project, you can either click the Record button, or from the Project menu, click New Audio Track. You will then see a blank track appear in the main Audacity window. A guitar is only a mono signal, so select to add a mono track.

Before we start recording anything, it’s worth pointing out a few key notes about the way Audacity handles audio tracks and files.

1. You can only have one clip per track.

This basically means that you cannot record on one track, hit stop, and then continue recording. Each time you press record, you will generate a new track. If this is for a guitar part that you are trying to record over different takes, you would need to record each section, and then edit the sections into a new track to make up the full guitar part.

2. Recording creates a new track

Each time you click record, Audacity will create a new track in the current project.

3. Edit / Duplicate does not create a new audio file

Audacity only references the original recording until you perform an edit function on it. When you cut a section of track, or add an effect, then Audacity will create a new with the changed data. You ca perform the undo / redo function as many times as you like, even after saving the project. You can actually re-open a project and undo every action until you are left with the original recording!

Make a final check to see that your signal is reaching Audacity by clicking the input monitor (the microphone at the top right of the Audacity window) button. When you strum the guitar, the meter should light up to around 3/4 of the way. This allows for some headroom to really hit the notes without any clipping, and also some room to play lighter without losing the signal. If the level is too low or too high, adjust the guitar or amp etc, until this is at the right level.

Audacity - Monitoring

So your settings are good, the file format is to your preference -- just have to hit record and you’re away! If you wish to stop recording and continue recording to the same track (I know -- I said you couldn’t do this) you can hit pause. It’s pretty inflexible as it stops everything, and you have to immediately continue recording and not select the start point.

As you record, a waveform will appear displaying your sound

Audacity - Waveform

If you end up with several tracks, it’s best to get into the habit or renaming them -- here I only have the one track called “Motorbreath” but if I were to record both guitar parts and the bass, then I would rename these accordingly. Click the down arrow in the top right hand corner of the track info to rename the track.

You can continue to record tracks in this way until you are ready to edit them.


Before we actually go into any post production and editing, there is a second way to get audio files into Audacity -- Importing. If you have recorded audio with another package or if you want to sample or play along with a song -- you can import the tracks into Audacity from the Project menu. Click Import Audio. You can import wav, aif, au, ogg and mp3 formats.

Audacity - Importing

The file will appear as a new waveform in the project window.


So, you’re plugged in and recording happily. The next part of any recording process is the post editing. This can take just as long as recording the audio itself -- sometimes longer!

Lets just have a look at those editing tools that we briefly named earlier.

Audacity - Tools 1

If you remember, these are the Selection Tool, the Envelope Tool and the Draw Tool. The lower line consists of the Zoom Tool, the Time Shift Tool and finally the Multi Tool Mode.

The Selection Tool allows you to click and drag a range of audio on a track. After selection, you can extend the region at either end by dragging the edges outwards. If you press the Z key after making a selection, Audacity will automatically adjust the start and end selection points to be at “zero crossings”. This is where the audio is at the 0db point (the central horizontal line) and hence prevents clicks or pops when the audio is moved around.

Audacity - Selection

The selection is also detailed in terms of start, end and duration in the status bar at the bottom of the Audacity window.

The Envelope Tool allows you write volume envelopes to a track. Simply click the envelope tool button. This adds a blue border above and below each track, and also an inner zone (light grey) that highlights the track waveform. By clicking on the track, you can add a node that can be adjusted up and down (adjusting the gain). The outer blue bar allows you to reduce the gain or bring it back up to the level of the originally recorded track. If you change a node from within the inner region, you can also reduce the gain, but (unlike with the blue bar) you can increase the gain, going past the level of the original recording.

Audacity - Envelope 1

Audacity - Envelope 2

Audacity - Envelope 3

These three screenshots show (above, top to bottom) the envelope added to the track, the track gain reduced at a point, and the gain increased (past the original level) at a point.

The Draw Tool allows you to fine tune the waveform to eliminate clicks or other unwanted noise. You will need to zoom in until you see the waveform notes which is down in the region of 0.001 of a second!

Audacity - Draw Tool

The Zoom Tool is pretty self explanatory. It lets you zoom in and out of the track. Left clicking zooms in, and right clicking zooms out. As well as the zoom tool, there are 4 other buttons that allow you to manipulate the zoom to fit the track or selection into the Audacity Window. These are found on the main toolbar.

Audacity - Zoom Tools

The first button will zoom in, the second zooms out. The third button fits the currently selected region to the width of the Audacity window -- useful for working on a specific section. The final button on the right will fit the entire track to width of the Audacity window -- useful for moving sections around in relation to the track as a whole.

The Time Shift Tool lets you move audio clips left and right along the timeline. Clips cannot be dragged into different tracks.

Audacity - Time Shift

The Multi Tool Mode will change function depending on where the cursor is place on the track. It will enable the envelopes you have defined for a track (and let you edit them), it also allows you to shift the clip around (time shift) and also adjust a selected region.

The next set of tools we will look at are the Cut, Copy, Paste, Trim and Silence buttons.

Audacity - Tools 2

Cut, Copy and Paste work as expected and the usual keyboard functions (Ctrl + X, Ctrl + C, Ctrl + V) also work. The only thing to watch out for is cutting a selection. This will close up the space where the cut section was. To leave a gap, use the Silence Tool. When pasting a selection, if you click with the Selection Tool, the clip will be placed at that point. If you click on an empty section of track (with no clip region) the pasted clip will be placed at the beginning of the first clip on the track. If you clicked at the end of the track in a blank area, the pasted clip will be added to the end of the last clip. Finally, if you click on a blank part of the Audacity track window (so no tracks are selected), the pasted clip will be added into a new track at the 0 time mark. This sounds quite confusing, so have a play around and it will become clearer.

The Trim Tool is rather like a crop tool in that it deletes everything in the track apart from the selected region. The Silence Tool is the exact opposite of the Trim Tool; it removes everything in the selected region, and leaves the rest of the track as it.

“One way to work is to record or import your narration or actualities into the first track, then go through the track, and when you find audio that you might use, select it and use the “split” command which will drop that section out to a new track. Name that track so you can recall what that clip is. Repeat until you have all your potential clips in separate tracks. You can then go in and fine-tune your edits on each clip, and then drag them around in time to put them in order. You can then delete the original track by clicking the X in the upper left corner of the track, because it only has the audio you didn’t use.”


The next step is to apply any effects to the tracks. These can be simple edits like a fade in or fade out, up to more advanced effects like a pitch shift, phaser or wah.

Because this article is aimed at using the software itself, I will not go into any detail on the usage of effects. The best way to learn is to just experiment! Select a clip and then go to the Effects menu and pick an effect to apply to the selection. You can preview most of the changes before clicking OK which is really useful for fine tuning the sound you are after.

The final step is to export your audio to a playable format.

Making sure you have aligned all of the individual clips into the right positions, you can then merge the clip tracks into one single track. You can merge all the guitar parts into one, and then all the bass parts into one (ending up with two individual tracks) or just merge everything into one complete mix.

Audacity - Tracks

These two guitar tracks are ready to be mixed together. The second clip is perhaps a retake on a difficult lead line, and as such has been re-recorded and then edited to fit with the top guitar track. Click play to ensure that the sound is correct before mixing these two together. When you are happy, select the two (or however many) tracks, and click the Project Menu and then click Quick Mix. The selected tracks will be removed and replaced my a track called “Mix”.

Audacity - Final Mix

This is clearly a very simple mixdown, but it shows the way in which Audacity works. Once you understand the tools, you can work with them on more complex tasks.

The last thing to do is to export the final track. Click the File menu and then Export As MP3 (or AIFF / Ogg Vorbis). Select a directory to save the file to, and you’re done.

I hope that has helped you with getting to grips with Audacity. If you have any problems, please click onto the forums and ask your questions there. Likewise, you can leave a comment below, and I can help with quick questions. Good luck!

Written by Alex on Thursday 7th September 2006 at 7:05pm and posted in Home Recording

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Your Comments

  1. January 25th, 2011 3:59amjuliasvision said:

    2 problems perhaps you can help me with:
    my mic input levels keep clipping/distorting. how do i lower the input level? with meter level? how? it won’t let me keep it in place.
    also, how do i cut/paste segment from 1 track onto another? As you say, “Making sure you have aligned all of the individual clips into the right positions”, …”edited to fit with the top guitar track”. how do i do this without being a second off and getting tracks out of sync?
    arggh!
    thanks so much!
    Julia

  2. January 25th, 2011 4:00amjuliasvision said:

    here is my email to respond please! thx!

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