Audio files and handheld devices were made for each other. Whether you have a smartphone or a dedicated mp3 player, you probably have — or want to have — a bunch of audio files on it, ready to make your day a little brighter. But working with audio files destined for your handheld is not always easy. That’s where some tools and know-how come in handy. Read on to learn about a few.

I have a bunch of MP3 files that I want to make smaller so that I can transfer them to my smartphone. How can I make the files smaller?

MP3 is already a compressed music file format. But as you probably know, there are multiple “bitrates” available for MP3, and these bitrates generally determine how much data is thrown away during the compression process — and how large the audio file sizes are. The higher the bitrate, the larger the file size. MP3 bitrates start at 32 kbps (kilobits per second) and increase in increments up to 320 kbps. Generally MP3s of 96, 112, or 128 kbps will result in small file sizes but retain good audio quality.

It’s easy to find audio applications that will initially create MP3 files for you from audio CDs. It’s not so easy, however, to find applications that will take a bunch of existing MP3 files and “downconvert” them to a lower bitrate. Thankfully, though, there’s one very good open source application that will do just what you’re looking for: CDex (http://cdexos.sourceforge.net).

Download the latest version of CDex, install it, launch it. Then, from the Options menu, select Settings. From the resulting CDex Configuration dialog box, there are two settings you want to concentrate on. First, from the left-hand navigation pane, select Directories and Files. Use the file location boxes to tell CDex where on your hard drive to place the converted files. Next, click Encoders in the left-hand navigation pane. Use the drop-down list boxes to set the “Bitrate Min” and “Max” values to the highest MP3 bitrate you will allow for your conversions. For small file sizes, choose a value such as 96 kbps. Click OK to exit the settings panel.

Now, back in CDex, click the Convert menu, and select “Re-encode Compressed Audio Files.” Use the file chooser to select the MP3 files you wish to resample. Once the files are listed, click the Select All button, and then click the Convert button. Your downsampled files will appear in the folder you chose from the Configuration dialog box.

How can I create playlist files for my handheld?

Many handheld devices, including BlackBerry smartphones, rely on so-called playlist files to determine the order in which a bunch of MP3 files should be played. Playlist files have the file extension m3u, and they are essentially simply text files a listing of MP3 files in a particular folder. However, rather than creating m3u files by hand, most people turn to some kind of utility to create the files for them. Windows Media Player, for example, has a Create Playlist button on its main toolbar.

Another useful tool is M3U Dropper (http://home.comcast.net/~enitzsche/m3u_dropper). With it, you can simply drag a folder full of MP3 files onto its main window (the files themselves are not actually copied), drop them there, and then click the big Create Playlist button. You’ll have the opportunity to provide a name for the m3u file. Once that’s done, your playlist will be created.

If you have a music library containing lots of files and folders, you’ll probably want a more robust tool that will scan all of the folders automatically and create playlists for each grouping of MP3 files. RinjaSoft creates a line of very efficient playlist creation utilities for BlackBerry, Nokia, Zen, and other smartphones. The tools aren’t free, but they will make short work of creating playlists from a large catalogue of files.

What’s the easiest way to get audio files from my computer to my smartphone?

Most smartphones come with desktop computer software that will make the job of moving or copying audio files easy.

Once you install that software, though, your smartphone will probably also show up as a removable storage drive on your computer, and you can also use a traditional file manager such as Windows Explorer to copy files directly from your PC to the music folder on your smartphone. That’s probably even easier than using the manufacturer’s desktop software.