Mp3 with FCP
 

first off , wanted to say hi as this is my first post. Also I imported some of my mp3's into some of my clips and the audio quality is poor. Is there something I'm doing wrong or should I stick with wav files?

Welcome Joe!

Because MP3 audio is so highly compressed it's generally not suitable for use in video editing projects, which generally use audio rates in the range of 44kHz - 48kHz for source material.

Ideally, you would use AIF files containing recordings at the above sampling range for your source material.

I usually convert my mp3's to AIF before dropping them into FCP. I import the file into QuickTime and change the frequency etc. if necessary and then export the file. The quality doesn't change, but FCP seems to handle the file better. Many people don't have a problem with mp3's in FCP, but mine is an older machine.

Final Cut Pro can handle WAV files without any problem whatsoever (at least FCP 2 can... FCP 3 may need to re-render the audio because FCP3 is just weird). They are essentially no different than AIFF files. The actual audio data is the same. Final Cut Pro can also handle AVI files encoded with the DV codec without any problem or rendering.

in my experience, i get weird static in my mp3 files, even when rendered if i drop them into FCP. i just use quicktime pro to export as aiff and then, no problems.

Use iTunes for audio conversion instead!
 

Despite the fact that FCP can handle multiple audio formats, it is generally recommended that you use audio in the same format as that used in the sequence. To learn what your audio sequence setting are, find the sequence in question in your browser, right click on it (control click) and select Sequence Settings. In the bottom right of the box that appears you will see your audio settings. Click on the Advanced button, and copy down the settings. For a standard DV project with audio from the camera these are likely to be Compressor>None, 48khz, 16bit, stereo.

Note: Checking your Sequence Settings to ensure your Capture Settings and Clip Settings all are the same (as much as possible) will save you a great deal of grief in the long run. Remember, changing Sequence Settings is impossible in a sequence with clips in it already, and changing Sequence Presets under Audio/Video Settings or Timeline Options under Preferences only affects the next sequence created, not any current sequences.

Now, though QuickTime can do a great job converting audio files, the free application iTunes does one better in that it is capable of batch conversions. Open iTunes (OS X example) and in the menu bar choose iTunes > Preferences. In the window that opens, click on the Importing button. Now, choose "Import Using: Aiff Encoder" and on the next button down, select Custom. Make your settings the same as in your sequence, in this example, 48khz, 16bit, stereo. You are done this part, so select Ok and Ok.

Now when you import files they will be converted to the same format as you are using in your FCP sequence. To import a folder of MP3s, or whatever, (do yourself a favour and put all of the material you wish to convert into a single on your harddrive) in the iTunes menu bar go to Files > Add to Library and select your folder of files to be converted (assuming they do not appear in a current Library file). Create a new folder in the Source column, cleverly naming it after your FCP project or something, and drag all of the files you want converted into this new folder. iTunes will then convert all of them.

By finding this newly created folder in the finder, you can drag the folder and all of its contents into the FCP browser (or File > Import > Folder in FCP). You now have a handy folder with audio files in the same format as your sequence, causing fewer headaches for your work.

Some people are concerned that a consumer app like iTunes cannot do a proper conversion. But iTunes uses QuickTime to do the conversions, so if QuickTime is good enough for you, iTunes is as well.

Note: I choose the workflow above for specific personal reasons of orgnization. There are other ways in iTunes of doing much the same thing. Work with what works best for you.