During our first Audacity session we used this application in order to record and play tracks. It’s high time we utilised Audacity to apply some effects and correction tools. We will use built-in and plugins. Windows users may install some VST effects, and Linux fans – LADSPA plugins in order to get the same results.

VST plugins can be also installed and used in Linux, at least some of them. If they are running using Vstserver, they will be visible as standard LADSPA effects. This time we will only use the built-in effects and tools, however.

Let’s begin:

1. Run Audacity. Record an audio track, or open a file recorded previously.

2. We will use Audacity’s built-in effects. They are available in all systems and Linux distributions, regardless of which LADSPA plugin packages are already installed. These tools are available in the Effects menu.

3. Many plugins are active only when the whole file, or some part of the recording is selected. Thus, we should begin with selecting track. At first, select only a few seconds at the beginning of file. We will apply a smooth fade in effect, in order to avoid clicks and cracks at the very beginning of the recorded file. So, select first several seconds of file, and then choose Effect > Fade in option. Audacity will apply the efect, changing the volume of sound within the selected area.

4. Let’s use the same effect at the end of file. Select last 5-10 seconds of the recording, and choose Fade out command from the Effects menu. Audacity will fade the sound into the silence smoothly.

5. Equalizer is one of the frequently used correction tools. It allows to remove, or to change the volume of certain part of the spectrum. This allows us to make some sounds or instruments more (or less) loud. We should rather decide to make unwanted parts of the spectrum more silent, than to raise the volume of all other frequencies.

Equalization.

Equalizer is available in the Effects menu. Use the Equalization command. A new window will appear. It contains the logarithmic graph of all recorded frequencies. Our aim is to create a curve which will eliminate undesired parts of the spectrum. We may use the predefinied curves, available on the list Select curve. We may also create our own curve (custom curve) and save it using Save As button. If we are not satisfied with the created curve, we should delete it by pressing the Flat button.

6. Compressor is the another important correction tool. It allows to reduce sound level of loud sounds, over a certain threshold. Quiet sounds are not reduced. This reduces the dynamic range of an audio signal, but on the other hand allows to improve audibility of recording. And the most important thing: compression makes both the soft and loud parts of a sound audible at the same time.

Go to the Effects menu and choose Compressor. In a separate window we should specify the threshold. Below this level sound is left untouched. The ratio determines the amount of gain reduction. Attack Time and Decay Time allow us to decide, how quickly compressor will react after detecting sounds over a certain threshold, and how quickly it will be turned off, when the volume become slightly lower.

Dynamic Range Compressor.

7. After applying the compressor and equalization our song may sound a little bit too silent. That’s because the volume level is now slightly lower – we’ve just remove some frequencies from the recording, and this changed the maximum amplitude of the track. We should then use Normalize tool, available in the Effects menu.

Normalization applies a constant amount of gain to the track to bring the highest peak to a target level. The target level can be specified using the Normalize maximum amplitude to option. The default setting is 0 dB. That means that the recording will be as loud as possible.

Normalize effect also allows us to remove DC offset. We should always use this option.

Normalization.

8. Audacity offers also some built-in effects, not only correction tools. Use BassBoost, Echo, Phaser, and Wahwah plugins, if you want to get slightly more unusual sounds.

This time we only used the Audacity’s built-in tools. Next time we will test some LADSPA plugins. And then we will learn how to remove noise and vocal tracks from the recordings.

This tutorial presents the most important functions of Audacity. Part 1 is devoted to issues associated with recording of audio files. Next parts will show how to use effects, mix tracks and remove vocals from music recordings.

Let’s begin and record our first audio track in eleven easy steps.

1. Download and install Audacity. This is very easy task, because there are binaries available for most of the Linux distributions. You will find them on your installation CD/DVD. If not, then visit the Audacity homepage, and click Download. You may also download Windows and MacOS X executables.

2. Start Audacity. The program will ask you to choose the desired language.

3. Begin with setting up preferences. Choose Edit > Preferences.

4. Adjust your Audio Input and Output settings (Audio I/O). Both OSS and ALSA drivers are supported. You may also use the JACK Audio Connection Kit. Just choose appropriate device on the Playback and Recording list.

Configuring input and output ports in Audacity.

5. Click Quality on the left. Choose desired sample rate (usually not less than 44100 Hz) and sample format. There are also some parameters used when converting sample rate of loaded or recorded audio files. We can choose fast or high-quality interpolation. Do not forget that the latter requires more processing power and may slow down the older machines.

6. If you want to open or save MP3 files, then take a look at the Audio Files pane. You will have to locate the appropriate library (LAME). If you hadn’t installed it earlier, use the Download Free Copy of LAME button.

7. Now we record our first audio file. Don’t forget to check if microphones or other devices are properly plugged into audio card ports. You should also correct the volume and panning values for appropriate ports. Open your favourite mixer (KDE users may use kmix) and make sure, that input ports (Capture or Microphone) are activated and the recording indicator is lit.

8. If you use tha JACK audio server you should also check the connections between ports. Use QJackCtl application. Open Connect window and choose Audio pane. Connect Readable Clients > alsa_pcm > capture_1 with the Audacity input port. You may also record sound from other audio applications. Just click the appropriate readable client.

9. In Audacity main window click the Record icon. That’s it. You will see the new audio track with your recording. If sound wasn’t recorded, check mixer settings.

If no sound was recorded, check your settings.

10. Now we will save our recording. Audacity writes audio tracks in its own file format (*.aup; choose File > Save Project). It allows to save evarything you are working on, but you will be able to open the project only in Audacity. If you want your recordings to be opened by all audio applications, then use the File > Export command. This will allow you to save WAV, MP3, OGG and FLAC files.

11. Audacity allows you not only recording sound from external devices (microphones etc.) and other programs, but also to generate sound using LADSPA oscillator plugins. They are grouped in the Generate menu. For example, if you want to generate nice organ samples use the Organ plugin. Specify frequency of the generated sound, its velocity and effects (gate). Note that this plugin is distributed with the separate CMT LADSPA library. It should be installed separately.

Generating sound using Organ LADSPA plugin.

We learned how to record audio tracks using Audacity. In the next part of this tutorial we will apply some effects and correction tools.