Rip your CD onto your Mac. With Mac OS X, you can rip your music using iTunes, Apple's official digital media software. Just insert your CD into your CD/DVD-ROM drive, open iTunes and click the "Import" button when the dialog box appears on your screen. You can also rip music using a Mac-compatible program like Roxio Toast or Windows Media Player. The software will save each song in MP3 format unless you specify otherwise.
Drag your first MP3 file into an audio editing program. Mac OS X Leopard and Snow Leopard both come equipped with GarageBand, but you can also use a Mac-compatible program like Cubase, Logic or Reason. For free options, download a program like Audacity, Ardour or Traverso DAW (see Resources). Just drag your audio file directly onto the audio editor software icon, which appears in the "Applications" folder (Macintosh HD > Applications).
Access your waveform editor. A waveform will appear as a long series of wavy lines along a horizontal bar. Some programs display your waveform editor by default, but others will require you to double-click the audio region (which looks like a shaded horizontal bar) or select an "Editor" view from your view options.
Remove vinyl clicks. When vinyl transfers to a digital format, the digital recording will maintain the pops, cracks and clicks transmitted during vinyl playback. You can reduce or eliminate these sounds using effects filters. For example, Audacity features a "Click Removal" filter under its "Effects" menu (accessed from the menu bar). Just highlight the area(s) where clicks appear and select the filter. Other programs offer similar filters, and in GarageBand, you can reduce clicks by applying a "Noise Gate." Just click the "Track Info" button (resembling a letter "i"), check the "Gate" box and apply the maximum exposure.
Remove any background noise or vinyl hiss. Many programs, like Amadeus and Audacity, offer a "Denoise" filter on the "Effects" menu. Logic also includes a "Denoiser" filter, accessed from the "Inserts" menu on the Logic mixer (Inserts > Specialized > Denoiser). The GarageBand "Gate" feature can also reduce noise, or you can use the "Speech Enhancer" effect (found on the "Track Info" menu), which filters out excess noise.
Equalize your audio. Almost every audio editing program includes an "EQ" filter, sometimes found under the "Effects" menu (as with Amadeus and Audacity), "Track Info" (as with GarageBand) or "Inserts" (as with Logic Express and Logic Pro). EQ allows you to improve the sound of a recording by isolating frequency ranges. For example, if your vinyl recording lost a lot of its bass sound during the transition to digital format, you can add bass by raising the amount of low frequencies. If the recording sounds tinny or sharp, you can lower the high (treble) frequencies. Experiment with each EQ parameter until you get the best sound.