A wave editor is the audio equivalent of a Swiss Army knife, but without the plastic toothpick. This month, Danny Allen shows you how to use some of the basic tools.
Let's get one thing straight. Audio (or wave) editors are no longer the exclusive domain of musicians and audio "uber-geeks". These days, they allow anyone to perform all sorts of common audio tasks.
At PC World's Web site (www.pcworld.idg.com.au) you'll find evidence to back this up, from articles on using audio editors to record an Internet radio stream, to guides on converting vinyl or cassettes, removing pops and clicks and converting the results to MP3 music files. We've also looked at converting between audio file types and trimming silence, or fading abrupt endings in MP3 files. So there are many things you can do with an audio editor, and that's before you've even thought about anything related to making music.
The more advanced the audio editing application, the more features and tools you'll find at your disposal. However, the cost and learning curve associated with specialist audio editors such as WaveLab (www.steinberg.net), Sound Forge (www.soundforge.com) and Audition (www.pacific.adobe.com) can be prohibitive to those of us with just a casual interest. As such, we've placed the free (yes, free), open-source Audacity audio editor (http://audacity.sourceforge.net) on this month's cover CD. It supports WAV, AIFF, MP3 and OGG audio files and is available for most flavours of Windows, Linux/Unix and Mac OS 9/X.
It's also worth noting that some PCs and components come bundled with all sorts of audio software. For example, some CD or DVD burners are bundled with Nero disc burning software featuring its own pert little audio editor.
When you open an audio file or record anything into a wave editor, a waveform is drawn on the screen from left (the start) to right (the end). If you see just one waveform, then it's likely that the audio is mono, whereas two waveforms usually indicate stereo, with the left channel waveform at the top and the right channel at the bottom.
Audacity's tool set is located at the top left and top right. You can use the magnifying glass button with a plus sign located near the top right to zoom in or the minus magnifying glass to zoom out. The next magnifying glass button in line will resize the selected portion of a waveform to fit the screen. Tip: You can also use the left and right mouse buttons to zoom in and out once you've selected the zoom tool (magnifying glass icon) at the top left. Also, if you have a mouse with a scroll wheel you can even scroll up and down while holding down <Ctrl> to zoom in and out. Thankfully, most audio editors work in a very similar fashion.
The various jagged edges of the waveform represent volume and sound changes and are generally called transients. A well recorded waveform will have lots of these peaks and troughs but, if it's too loud, the peaks will flatten out at the top causing an undesirable effect known as clipping.
Tip: to avoid clipping when you're recording, keep an eye on the volume meters (located at the top right in Audacity) to make sure your input source doesn't meter into the red.
Transients back up your ears by allowing you to see, as well as hear, what and where parts of the audio are - to perfectly select a loop or sample you want to copy, for instance. After clicking the selection tool, selecting parts of the waveform is a simple click-and-drag affair. Although there are buttons for each on Audicity's tool bar, your workflow will speed up through the use of conventional Windows shortcut keys like <Ctrl>-C to copy, <Ctrl>-V to paste, <Ctrl>-X to cut/delete, <Ctrl>-Z to undo and <Ctrl>-Y to redo.
Split and export MP3s
OK, so you love to support your favourite band by actually buying their music, but you recently downloaded from their Web site an hour-long MP3 of a live gig recording. Sure, you could copy this to your MP3 player or burn this MP3 to an audio CD as-is, but you won't be able to skip between tracks. Solution: split the MP3 yourself.
Initially, Audacity won't be able to export to MP3, so you'll first need to download and unzip the LAME MP3 Encoder Library you'll find linked on Audacity's Web site. Then in Audacity itself, go to File-Preferences-File Formats. Click on the Find Library button, browse to the directory you unzipped the LAME MP3 encoder DLL file to, and press OK. Set the MP3 bit-rate (quality) setting then click OK one last time. Now simply File-Open your hour-long MP3 file and use the selection, zoom and playback tools to select the gig's first track. Choose Export Selection as MP3 (or WAV) from the File menu and save it as track one. Repeat until you're finished.
When selecting a particular section (track or loop, etc) within a waveform, zoom in and try to ensure that the start and end of your selection is on transients close to the centre of the waveform - this will ensure a smooth loop, cut or copy. This is called finding the zero crossing and, by pressing <Z> (or going to Edit-Find Zero Crossing), Audacity will try to reselect to the closest points for you. Zooming in will also help you find them yourself and pressing <Shift>-<Spacebar> will playback the selection as a loop, so you'll be able to hear as well as see the results. Have fun and for more information on Audacity, also see http://audacityteam.org.
When it comes to audio editors for professionals, it's hard to go past Sony Pictures Digital Networks' almost industry-standard Sound Forge, which is now at version 7. High-end audio recording, processing, editing and effect features abound, plus you can sync audio to video, create CD projects with the bundled CD Architect 5 and remove pops and clicks from vinyl recordings with the bundled Noise Reduction plug-ins. The problem is, all these great features will set you back $649, putting it out of the reach of many.
For this reason, a stripped back version called Sound Forge Audio Studio has been released, and priced at a much more entry-level-friendly $249. The majority of Sound Forge's excellent feature set remains intact, but cut downs include reduced support for high-quality audio (the maximum is 16-bit, 48KHz), plus the removal of Direct X plug-in support, MIDI triggering, a plug-in chainer, waveform envelopes, undo/redo history and acoustic mirror reverbs.