Web Design in a Nutshell, 3rd Edition

Optimizing for the Web

After the sound files have been recorded and edited, it is time to convert them to their target web audio format and make them as small as possible for web delivery. The tool you use may depend on the file format. There are also several tools specialized for the creation of MP3s. Tools are discussed with their respective file formats later in this chapter.

One great all-purpose tool is Autodesk’s Cleaner, which is available for the Mac and Windows systems. This program is designed to get the best quality files at the smallest size in whatever format you choose. Cleaner can compress a number of file formats, including QuickTime and RealMedia. It can also do batch processing. The program sells for about $500 as of this writing. Regardless of the tool you use, there are standard ways to reduce the size of an audio file so it is appropriate for downloading via a web page. Not surprisingly, this usually requires sacrificing quality. The aspects of the audio file you can control are:

Length of the audio clip

It might seem obvious, but you should keep the audio sample as short as possible. For example, consider providing just part of a song rather than the whole thing. If you are recording a greeting, make it short and sweet.

Number of channels

A mono audio file requires half the disk space of a stereo file and may be adequate for some audio uses.

Bit depth

Audio files for the Web are often saved at 8 bits, which will result in a file that is half the size of a 16-bit ...