Choose the Right Audio Tools

Choose the Right Audio Tools

Download free audio software, and spend your money wisely on the right commercial audio software.

A wide variety of free and commercial audio tools are available for podcasting. But that doesn't mean it's easy to find the right software. You can spend a lot of money on an application that is great for musicians but doesn't have the right functions for podcasters.

In this hack, I cover both the free and commercial tools, explaining which ones are good for podcasting, and why.

Audio Editors

Audio editing applications allow you to edit sound as though you're using a word processor. You can cut, copy and paste, delete, and arrange sound in any way you choose. Most of these applications allow you to work with multiple tracks that you can think of as sonic layers. You can use these tracks to work with each sound in isolation, and then mix down to a single mono or stereo signal at the end. In addition, many of these applications allow you to apply effects to the volume or the character of the sound.

1.1 Audacity.

Audacity ( is a free sound editing program that runs on Windows, Mac, and Linux. You should download Audacity and install it right now. It's an excellent starter program and it's possibly the only editing program you will ever need. Figure shows the Audacity main window.

On the recording side, Audacity supports mono and stereo recording from any sound input source on your machine. It even has meters in the document window to show when you are clipping (cutting off a portion of the signal). Unfortunately, plug-ins [Hack #51] are not supported during recording. So, you will need to do all the filtering work after the recording.

Audacity has excellent editing capabilities. You can zoom and scroll on both the time axis and the amplitude axis. The keyboard controls for navigating around the document and then creating and extending your selections are easy to use. Cut, Copy, and Paste all work as if you were in a word processing document. However, copying and pasting between documents of different sampling rates can get tricky.

Audacity supports envelope editing. With this feature, you can manually boost or reduce the amplitude of parts of the recording using simple visual cues. This is very handy when you have sections of audio that drift from very soft to very loud.

Audacity's main window

When you download Audacity, you should also grab the LAME MP3 encoder and the Virtual Studio Technology (VST) plug-in support module. VST is a plug-in standard that is supported by a number of sound applications on both Windows and Macintosh. Audacity has a variety of filters already baked in, but the VST plug-in support expands your sonic toolkit tremendously.

1.2 Pro Tools free.

Digidesign ( is so cool that it released one of its earlier versions of Pro Tools completely free to the public. Pro Tools is a commercial-quality recording application that, in its current version, is coupled with the company's Mbox hardware [Hack #12].

Unfortunately, this version works only on Windows 98 and Mac OS 9. It does not work on the Classic emulator on OS X. If you are running on Windows 98 or OS 9, this is a heck of a bargain. Some Macintoshes can dual-boot between Mac OS X and OS 9 to save you a lot of money.

1.3 Peak 4.

BIAS's ( Peak 4 ($499) is one of the premier sound editing tools on the market. It has a remarkably intuitive interface that allows you to find the samples you are looking for quickly in the alien world of waveform display. Peak is shown in Figure.

Sections of audio can be delineated into regions and exported separately automatically. There is also an interface for batch edits to multiple files.

Peak on Macintosh

Perhaps the most appealing feature is the Vbox, which allows you to arrange multiple effects [Hack #51] together and stream the currently selected audio through them over and over until you get the sound you are looking for. You then bounce the signal through the Vbox to apply the filter to the signal.

Peak also has a recording feature that shows the stereo input waveform as it's being recorded.

Peak's sister application, Deck ($399), is a studio-quality recording application that supports mixer functionality with unlimited virtual software mixer channels. It's overkill for podcasters, but if you are creating a home studio for podcasting and music, you should check it out.

1.4 DSP-Quattro 2.

Another high-end sound editing package for Macintosh is DSP-Quattro 2 ( The list price is around $149. It supports region editing as well as both VST and AU effects plug-ins, and has an intuitive interface for making your edits. For the price, this is an awesome sound editor.

1.5 Audition.

On the Windows side of the recording and mixing cycle is Adobe's Audition. Audition was originally Cool Edit, and then Cool Edit Pro, before it was acquired by Adobe. It's a professional's product at an amateur's price that has had years of honing.

With Audition, shown in Figure, you can multitrack record and edit. It offers a reasonable set of built-in effects, and you can extend the processing using VSTs. It has a high-quality tunable noise filter built in. On the output side, a number of formats, including MP3, are supported.

Adobe's Audition, which used to be Cool Edit

On the downside, the interface is initially very complex and will be familiar only to those with experience in multitrack recording systems. On the upside, the documentation that comes with the product is an excellent introduction not only to the software, but to the science of audio recording as well.

1.6 Sound Forge.

Sony's Sound Forge (, which is pictured in Figure, is a full-featured, multitrack recording and editing application for Windows.

A full complement of effects is built in, but it also supports the VST plug-in standard so that you can add your own effects. An audio editor is built into the product, as you can see in Figure in the lower righthand corner of the main window. The package includes noise reduction tools that will help you clean up sub par recordings.

Sony's Sound Forge application

If video is your thing, you can import video and sync up your audio editing with it. If creating music loops is more your style, this program integrates with Sony's ACID program. You create the loops here [Hack #63] and then use ACID to choreograph them into a song.

At the time of this writing, Sound Forge sold for $299.95.

1.7 n-Track Studio.

n-Track Studio (, written by Flavio Antonioli, is a multitrack recording and mixing program for Windows. It's relatively inexpensive at $49 for the limited edition and $75 for the full version. n-Track Studio is shown in Figure.

A demo is available online that you can use for a limited time, to get a sense of its features. It has a pretty daunting interface, but once you get the hang of it, you can get to recording and arranging pretty quickly. It does not have a built-in signal editor, so you will need Audacity or Sound Forge to edit your recordings directly.

n-Track Studio

1.8 GarageBand 2.

GarageBand 2, pictured in Figure, comes bundled with Apple's $49 iLife 5 suite. It's a steal alone at that price. The inclusion of the other iLife applications makes it just that much sweeter. GarageBand is good for both recording and mixing sound.

GarageBand 2

Along the right side of the window are the tracks of the recording. Each row contains little blobs of audio. You can change their duration as well as their placement in time.

GarageBand doesn't support robust sound editing. So, you will still need an application such as Audacity or Peak to do your editing. However, GarageBand's ability to string together audio loops makes it ideal for making musical melodies for intros, outtros, bumpers, and stingers.

1.9 Logic Express 7.

Logic Express 7 (, $299, is the Apple product that is one step up the scale from GarageBand 2. It's a sophisticated multitrack recording, editing, and production tool. Logic Express is shown in Figure.

Logic Express on Macintosh

The multitrack recording and editing capabilities are ideal for a home studio music recording setting. For podcasting, it will have way more functionality than you require, but at $299, it's hard to say no.

Sound Recording Applications

A few applications specialize just in the recording of sound. Some of these subspecialize in taking sound directly from applications in addition to traditional sources, such as microphones.

2.1 Audio Hijack Pro.

Audio Hijack Pro (, $32, is a Macintosh podcaster's best friend. It's an application that can record audio from any sound input, or any running application. This means you can integrate music or sound from iTunes directly into your recording. Figure shows the Input tab of an Audio Hijack Pro session.

Audio Hijack Pro's Input tab

On the lefthand side of the window is the list of sessions. Each session, as specified on the righthand side of the window, has an input and output source, details about where the output file is supposed to go (in the Effects tab shown in Figure), and the grid of effects.

Audio Hijack supports a set of effects to alter the sound of your recording as you make it. These effects are strung together in an intuitive graphical format.

Through the Voice Over effect, you can bring audio from iTunes into your recording in real time. It's this ability to hijack sound from other applicationsalong with the application's incredible stabilitythat makes Audio Hijack Pro a very popular recording tool for Macintosh podcasters. Rogue Amoeba, the publisher of Audio Hijack Pro, has noticed this, and subsequent versions of the software are being built with podcasting in mind [Hack #52].

Audio Hijack Pro's Effects tab

2.2 Total Sound Recorder.

The inexpensive Total Sound Recorder (available at: is a favorite of Windows podcasters. The standard edition costs $11.95, and the professional version costs $39.95.

You can use the Total Sound Recorder Pro main window, shown in Figure, to record audio from all the standard input sources, as well as from applications.

Total Sound Recorder Pro

2.3 Audio In.

Another freeware recording tool is Audio In ( This is a nicely put together application that does one thing, record sound from any input, and does it well. As you record, an attractive oscilloscope display shows the signal.

Podcasting Applications

With the advent of podcasting have come specialized podcasting applications. These applications combine sound recording, rudimentary editing, and mixing, and also automate the encoding and uploading process.

3.1 iPodcast Producer.

iPodcast Producer is an all-in-one podcaster application for Windows. Figure shows one recorded segment of audio.

iPodcast Producer

Using this application, you can record your voice segments and drop in prerecorded effects and sounds that you can assign to hotkeys. A companion application enables you to edit the individual sound files to add some effects or to remove "ums" and "ahs" from your voice track.

Once you are done developing the podcast, the application will mix it down to MP3 or WAV format for you. It will even go as far as to upload the mixed file using FTP, and update your RSS 2.0 feed [Hack #37] to add the podcast with the correct enclosure tags.

iPodcast Producer is available for $149.95 at

2.3.2 Winpodcast.

One of the first podcast authoring applications is Winpodcast ( It has a recorder, show notes, and a cart interface, all built into one application. This application is still in its early days, but it looks promising for simple podcast productions.

3.3 MixCast Live.

MixCast Live ( is the first Macintosh podcasting application. It has a show notes area, a cart for samples, and a recorder built into the application. It was prereleased at the time of this writing. The purchase price was $59, but you could get a $20 discount if you wanted to take the leap early.

3.4 Propaganda.

The oddly named Propaganda ( from MixMeister Technology is a Windows podcasting application that costs $49.95. Segments can be recorded and multitrack mixed in the application. Then the show is encoded and uploaded to your site using a built-in file transfer mechanism. The application also handles creating the RSS 2.0 XML file for the podcast and uploading it to your site.

Cart Applications

Radio studios used to have racks of specially designed audio tapes called carts that held spots and commercials. Today these units are digital and are controlled with a special control surface that the DJ or engineer uses to trigger the sample or sound effect.

Several PC- and Mac-based cart applications are available for injecting sound into your show on demand. These applications are listed in the sections that follow, as are hacks that cover building your own cart application for Macintosh [Hack #54] or Windows [Hack #55].

4.1 JazlerShow.

JazlerShow ( is a freeware cart application for Windows. You can place up to 30 samples in a grid and then play them on request with the click of a mouse.

4.2 Sound Byte.

The options for Macintosh cart programs are limited. Sound Byte ( is a $24 sound cart application that can preload an unlimited number of sounds into a grid. To play the sound in the cart, you simply click the button.

Helper Applications

Here are a few more applications that will help you develop your podcasts.

5.1 Soundflower and Soundflowerbed.

Soundflower ( is a handy sound routing utility for Macintosh. It creates two virtual sound drivers: Soundflower 2Ch and Soundflower 16Ch. These drivers support 2 and 16 channels, respectively.

The value of Soundflower is that you can specify a Soundflower port as the input or output of any application and then route sound through to it from another application. For example, you can route the output of Skype or iChat through Soundflower and into a recording application, thus recording the output of a Skype call [Hack #35].

Soundflowerbed, available on the same site, is a handy helper application that allows you to monitor your Soundflower channels.

5.2 FuzzMeasure.

FuzzMeasure ( measures the noise in your signal path and environment. It's a $49.99 application, but the company has a demo download that you can use to get some results if you are merely curious. The application actually simulates the environment using white noise and then calculates the response from the signal path and the environment.

5.3 Frequency.

Frequency ( is a freeware application for Macintosh that provides an image of a sound source of the frequency domain. When editing sound, we normally look at audio in the amplitude domain. We see the audio signal as it moves up and down in waves over the time axis.

Another way to look at sound is in the frequency domain. We do this when we look at a graphic equalizer. Each bar represents a frequency and the height of the bar is the amount of volume present at that frequency.

Working with Frequency is like looking at a graph of these graphic equalizers laid out along the recording's time axis. The darkness of the band indicates the intensity at that frequency. Figure shows the Frequency main window.

Through the miracle of really tough math, you can also edit in the frequency domain, literally removing or adding sound by frequency rather than by changing the signal itself.

Frequency main window

Practical applications for a podcaster working with just her voice and some effects are somewhat limited. But you can use the tool to determine the frequency of particularly nasty transients and noise, and even remove them.

Another free application that works in the frequency domain is FFTea ( At the time of this writing, the 1.0 version had been released but a bunch of features still were missing.


Most of the software products listed here have evaluation downloads that are good for a certain period of time. My suggestion is that you always try before you buy. It's easy to get an application that is overkill for podcasting, and then get lost in the complexity. If you can't figure out how to get a track or two recorded within five minutes of installing the application, you should probably look for something that you are more productive with.

When it comes to recording, you will get the same result from all of these applications. Since the source of noise [Hack #15] is in your equipment and your environment, your recordings will have the same amount of noise no matter what you choose. So, there is no benefit to going up-market on the recording side. The same cannot be said of effects, plug-ins, and filters. There are variations in quality there, and you should test them with your own ears before you buy.

The best advice I have ever heard about digital recording is that you put the money in the microphone, and then work back along the signal path to the software. You can always get better software, but it's impossible to get better source recordings after you have made them.

See Also

     Python   SQL   Java   php   Perl 
     game development   web development   internet   *nix   graphics   hardware 
     telecommunications   C++ 
     Flash   Active Directory   Windows