Cybercasting:

Creating Your Own Radio Station

David D. Thornburg, Ph.D.
Thornburg Center
DThornburg@aol.com
http://www.tcpd.org


Over the years I've worked in a variety of media - radio, television, and print. One of my favorites is radio. There are several reasons for this. Television requires a lot of outside support and is expensive to produce. Radio production, on the other hand, is comparatively cheap.

When I had a daily radio show, I taped segments as if they were live broadcasts. The freshness of this approach lent some excitement to the programming and held listener's attention better than some highly-produced (and considerably more expensive) programs.

By choosing to produce my own programs, I amassed a fairly nice set of recording and production equipment for my studio and then dropped my completed tapes off with the station for later playback. The only problems with radio (or television, for that matter) had to do with getting air-time and sponsorship. I owned the production and content, but the rest was out of my hands.

Now, I'm cybercasting an audio interview show, Perspectives on Education, (http://www.tcpd.org/tcpd/perspectives.html) and having a ball. Why? Because I not only have the production and content under control, I also, in effect, have a personal radio station as part of my web site.

In principle, millions of netizens can drop by to listen to any of the shows in my library any time they wish. I don't have to worry about "prime time bottlenecks" or sponsorship. "Air-time" translates to disk space on the server I use, and each 15-minute show takes less than a megabyte of storage.

Through cybercasting, my program can reach web users all over the planet, not just listeners in a restricted geographical area. In other words, my show can reach an audience more geographically dispersed than is reached by ABC, CBS and NBC combined.

More importantly, you can do the same thing I did and open your own cybercasting station for free as part of your home page.

We've all heard the promise of the 500-channel universe. Well that model has been blown out the window. If there are 20 million web pages out there, we have the potential of 20 million channels vying for a share of our ears and eyes.

This breakthrough is so important I want to share my motivation for cybercasting so you can see how it might make sense for you or those with whom you work to take the plunge.

Why did I do it?

The Thornburg Center provides staff development to educators around the general theme of emerging technologies and their effective use as tools for learning. We are one of the few futures research organizations devoted primarily to education.

Most of our work entails visiting with clients, speaking at conferences, and conducting workshops. One of the challenges we face is maintaining momentum after we have left the client's side. Our web site is one vehicle we have for providing ongoing support. We use our site to post written documents (such as this one), but I wanted to do more - I wanted to provide access to taped interviews I've been conducting with leaders in the field of education in my trips around the countryside.

Cybercasting was the answer.

The beauty of this approach is that I don't have to worry about making the content appeal to a "mass market" audience. By providing audio on demand, I am perfectly happy to reach only those who know specifically what they want to hear.

What's in it for you?

Educators who see value in the cybercasting concept can use it at their own sites for student productions. Oral histories can be captured from the grandparents of our students, and these can be used to form an on-line library of stories of our past. During the production of these programs, students acquire interviewing skills, and learn the intricacies of production. Unlike television, the technology needed to do this is fairly inexpensive. The only limitation is space on your server and the extent of your imagination.

Technical details

The first few steps in creating audio programs for web-based delivery are the same as those used for radio production. A program format needs to be chosen (interview, narrative, etc.) and a script or set of questions for a interview must be blocked out. Given my love of "live" broadcasts, I tend to work from an outline rather than from a script, but that just reflects my sweaty-palms approach to life.

How long should the program be?

The answer to this depends on the nature of your topic. Given the realities of transferring files over the web using cheap modems, I keep my shows to about 15 minutes. This is long enough to explore some interesting ideas, yet short enough to hold people's attention.

Making the recording

The recording should be made with a good tape recorder using decent microphones. The reason for this is that each stage on the production process for cybercasting degrades the original content. It is best to start with the best recording you can make. You don't have to be ridiculous, however. I use a Sony Walkman Pro recorder (http://www.sony.com) with a pair of condenser lapel microphones that cost about $30 apiece. For interviews, my mike is recorded on one stereo channel, and the guest's is recorded in the other. Radio Shack sells an adapter that brings each mike input into a standard stereo phone plug so the whole recording system is quite compact.

I record on high quality tape using Dolby B noise reduction, and make sure the recording level is set properly - neither too low, nor too high. Too high a setting produces distortion that can't be removed later.

The recording location needs to be chosen carefully. For interviews, I'm usually at airports, hotels, or conference centers - not in recording studios. While a certain amount of background noise lends a sense of presence to the recording, be careful to record in as quiet a setting as possible. Bowling alleys, for example, are off my list as recording sites, as are video game parlors.

Once the show is on tape, the rest of the production is pretty easy. Basically, you have to transfer the audio file from your tape recorder to your computer. In addition to your tape recorder, you'll want another piece of equipment: an audio mixer. The purpose of this device is to take each of the channels of your recording (two, for my interviews, for example) and mix them down into a single audio channel for transfer to the computer. During this process, you can adjust the volume levels for each channel, and change the equalization (high-tech jargon for treble and bass settings) for optimal playback from your web page.

My favorite mixer is the Mackie 1202 - a professional mixer that is very affordable for schools and home-based studios. As with your recorder, you'll want the best mixer you can afford just to keep from adding any noise or distortion to the signal.

Getting the audio into your computer

Once you have your tape recorder hooked to your mixer, and the mixer hooked to your computer, you are ready to turn your audio tape into a digital recording.

There are lots of audio recording programs on the market ranging in price from free to prohibitively expensive. If you are keeping with the spirit of live radio (especially AM-quality audio with little or no music), the free option works just great.

What you want is a recording program that records directly to your hard disk instead of your computer's RAM. The reason for this is that you'll want your digital master to be recorded at 16-bits of resolution at 22 kHz - a moderately high-quality setting that eats up a few megabytes per minute. Unless you have an unlimited RAM budget, you'll want to just spool this audio right to your hard drive. The Iomega ZIP drive (http://www.iomega.com) is perfect for this task, and the 100 megabyte cartridges are only about $15 each.

I do my recording on a Macintosh using SoundMachine 2.2.2 (http://online.anu.edu.au/RSISE/teleng/Software/welcome.html) and save the audio as an "AIFF" file. This platform-independent standard is best suited for direct recording to disk. While SoundMachine 2.x is an old shareware program, and it lacks many of the features I treasure in audio recording software, it is reliable and records directly to the hard drive, instead of saving the massive audio file in RAM. I expect other quality audio recording programs that spool to disk will become available as shareware soon.

As with the original recording, set the level carefully. Too high a recording level produces distortion. Your mixer will let you balance the volume of the host and the guest (for an interview) so they both record at the same volume level. Experiment with level settings by recording a few minutes from the tape, then play it back. If the audio sounds scratchy or clipped, you probably have the recording level set too high. Be careful at the other end as well. Recording at too low a level makes the sounds hard to hear. A bit of experimentation will provide just the right balance.

Preparing the file for the web

Given the fact that most of our clients access the web with phone-based connections using a 14.4 or 28.8 kB/sec modem, it would be foolish to place a 30-50 megabyte file on my site, no matter how compelling the content is. Fortunately, this is not an issue. Companies like RealAudio (http://www.realaudio.com) have developed special compression and playback tools geared to the realities of today's web.

As a supplier of cybercast material, you'll need two pieces of software - both available for free from RealAudio. The first of these is the RealAudio conversion program that translates your huge AIFF file to a very compact, but high quality, file based on the RealAudio (.ra) sound format. This program is fairly easy to use. It allows you to enter information about the recording that appears on the user's screen during playback, ad it gives you two choices for audio quality. The highest quality setting is for playback on 28.8 kB/sec modems or faster. I use the lower setting for 14.4 kB/sec modems instead. This results in more compact files (reducing download time) yet still produces adequate quality audio for voice. The resulting sound quality is similar to an AM radio playing through a small speaker.

You'll also need a copy of the RealAudio player software, as will your listeners. We provide a link on the Perspectives page right to RealAudio's site so our users can get the player software if they don't already have it.

If you set your site up so people will download the audio file before playing it, this is all you'll need. Before posting any files to your site, however, be sure to contact your service provider to be sure they have set up the RealAudio "MIME type" on their server. This is a simple, but essential, way to insure that when a user clicks on one of your files it downloads properly.

RealAudio's instructions are quite clear, and it took only two tries before I had everything working smoothly!

Streaming vs. downloading

An alternative playback method supported by RealAudio is called "streaming." Instead of downloading the file before playing it, a "streaming playback" starts playing sounds right away as the file is being read. This is essential for live broadcasts, and has its place for archived materials as well. In order to support this feature, your service provider will need to purchase the RealAudio server software and install it on their host computer.

Since many of our users pay for their own access, we opted for the "download" method because a 15-minute program can be downloaded using a 28.8 kB/sec modem in about 5 minutes. Once downloaded, the file can be played back off-line, and even copied onto a floppy to be given to someone else.

As with much of the recent evolution of the web, cybercasting opens new creative doors for all of us. It has long been said that the power of the press belongs to those who own them. With a bit of free software and some creativity, you can own your own cybercasting station!

Note: Case studies and references to specific companies do not imply an endorsement of any investment in their securities. The Thornburg Center does not give investment advice of any kind.

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