How to burn CDs

From Audacity Wiki

CD Burning

Audacity does not burn CDs directly; this page describes how to export audio files from Audacity 1.2.x and 1.3.x versions suitable for burning to different types of CD using additionalexternal burning software.

Different types of disc

There are two main types of CD that you can create with CD burning software - an "audio CD" and a "data CD". An audio CD (officially "Compact Disc Digital Audio" or CDDA, or Red Book audio) will play on any standalone CD player, as well as as in your computer and in DVD players. A data CD (sometimes called an MP3 CD where the data it contains are MP3 files) will not normally play on standalone CD players. It will play on computers, most DVD players and in MP3 CD players. So if you want to play your CD on a standalone player, or give it to others and be sure they'll be able to play it, you'll need to burn an audio CD.

When buying blank CDs for recording/burning, it is strongly recommended that you purchase CD-Rs and not the re-writeable CD-RWs.

Audio CDs

Audio CDs always contain high quality uncompressed PCM stereo data at 44 100 Hz sample rate, 16 bit resolution. So if you want to burn an audio CD, you should always export the file you want to burn as a 44 100 Hz 16 bit stereo WAV or AIFF file. To configure Audacity to do this:

1. At the bottom left of the Audacity window, set the Project Rate to 44 100 Hz.
2. Go to the File Formats tab of Preferences, and in the "Uncompressed Export Format" dropdown, choose WAV (Microsoft 16-bit PCM) or AIFF (Apple/SGI 16-bit PCM).
3. If your Project does not already contain a stereo track, click Project > New Stereo Track. It does not matter that this track is empty, its purpose is just to make Audacity export your recording as a stereo file. This step is not needed if you are burning to CD with iTunes.
4. Click File > Export as WAV or File > Export as AIFF.

Because audio CDs must always contain uncompressed 44 100 Hz 16 bit stereo audio, they are necessarily limited on a 650 MB ("Red Book Standard") or 700 MB audio CD to 74 - 80 minutes playing time respectively. If you need more playing time (e.g. to try and accommodate a C90 cassette or two LPs onto one CD), some CD burners will let you "overburn" into the blank CD space so as to extend the playing time by a further few minutes, so giving you the possibility of up to 80 minutes' playing time on a 650 MB disc or up to 86 minutes on a 700 MB disc. Overburning (if your burning software and burner supports it) is always done using Disc at Once (DAO) mode in which the tracks are burnt continuously without turning the laser off. It is also theoretically possible to overburn using "90 minute" (790 MB) or "99 minute" (870 MB) CD-R discs. However there is no guarantee whatsoever that your CD burner will accept such CD-R discs, or that your CD player will play anything other than a Red Book Standard 650 MB disc burned with 74 minutes of audio.

Data CDs/data DVDs

For burning really long files to optical media, you must burn either a "data CD" or a "data DVD". For example, burning MP3 files to a 700 MB "data CD" (sometimes called an "MP3 CD"), and using Audacity's default 128 kbps MP3 export bit rate, gives over 11.5 hours' playing time. But if 64 kbps MP3 bit rate was chosen (in Audacity 1.2.x at "MP3 Export Setup" in the File Formats tab of Preferences, in 1.3.x in "Options" at time of export), about 23 hours of audio would fit on the CD. Note the penalty of reducing the bit rate would be reduced sound quality.

A single layer 4.7 GB data DVD can accommodate nearly 80 hours of 128 kbps MP3 audio, though some older DVD players won't play DVD data discs, or only those containing certain audio or video formats.

Burning software

Most computers already come with media player software that can burn CDs. For example you can use Windows Media Player built into Windows or iTunes built into Macs. In either of these applications, drag the files you want to burn from the location you exported them to into a "playlist". Real Player is different and requires files to be added to "My Library" with its File > Add Files to My Library command before burning. If you have not yet created a Real Player library, see this link  and for help burning to CD on Real Player go here .

You can also use a standalone burning program like CDBurnerXP, Nero or Toast to burn your exported files. In this case, open the files from within that software, do not drag and drop them from your file manager.

Before burning, don't forget to choose the correct type of CD to burn, as explained above. For example, to set iTunes to burn an "audio CD", go to the Advanced tab of its Preferences, click the Burning tab, and at "Disc Format", select the "Audio CD" radio button.