Choose a bit rate from the drop-down list. A higher bit rate creates larger, higher quality files. The Bit Rate allows you to select the trade-off between the size and the sound quality of the compressed file. Compressing to higher bit rates will provide better sound quality, but will also create larger files.
Bit rate is specified in bits per second. As a rule of thumb, bit rates of 120,000 bits per second or higher offer near CD quality sound. Lower bit rates can be used, with a corresponding decrease in quality. If you are preparing your project for distribution on the web, lower bit rates will create smaller files, and therefore faster downloading time.
The maximum bit rate that you can select depends on the sampling rate of the project. The encoder supports bit rates up to 320000 bit per second, providing extremely high quality compression. Selection of 320000 bits per second or lower requires that your project was created using at least a 32 kHz sampling rate. If your project was created using a lower sampling rate, your selection of bit rates will also be limited.
Instead of producing a constant bit rate throughout the file, the Variable Bit Rate option optimizes the bit rate in different parts of the file to use a higher bit rate where it will make a difference, and a lower one where it won’t. This option generally produces a better quality file than constant bit rate encoding, but doesn’t produce the predictable file size you might need for downloadable files.
MP3 encoding uses several techniques for analyzing sound and creating MP3 files. The slider provides the user with the ability to specify how much time the encoder should spend analyzing the file.
When the slider is positioned to the far left, the encoder will spend more time analyzing and compressing the file. This will result in the highest quality MP3 file, but it will take longest amount of time to compress it.
To reduce the time required to encode a project, you can position the slider further to the right. This will compress files quickly by reducing the time spent analyzing the project. The trade-off for compressing quickly, or optimizing for speed, is that the resulting MP3 file may have a lower sound quality.
Check this box to include ID3 information with your MP3 file. The following fields are where you enter ID3 information that is stored in your MP3 file and displayed in most applications that play MP3 files.