Get Better Sound From Your iPod®
Use lower compression for higher audio quality
An iPod® or iPhone® makes a great music player. The convenience is undeniable, but unless you've made a little tweak to your iTunes®, you might not be getting the best sound out of your player.
Here's the problem: most of the music imported into iTunes is compressed down from its original file size, a process that strips out the full depth and detail of the original track. Might not seem like a big deal. But anyone who's ever experienced the impact of a movie's soundtrack in the theater, and then felt less than impressed hearing it through TV speakers, understands the difference good sound can make. That same concept applies to music: just like with a movie's soundtrack, more detailed and dynamic sound means a more engaging, fulfilling listening experience.
So who cares about compression?
When an audio file is compressed, various bits of sonic information are discarded. The current default sampling bitrate of 128 kilobytes per second (kbps) that most music programs (including iTunes) use represents something of a compromise. It keeps file sizes small, so you can store a lot of songs on your player, but it gives up quite a bit of audio quality.
An uncompressed track ripped from CD is about ten times the size of its 128 kbps counterpart. So how much sonic information is discarded in the process? Well, imagine the difference between the appearance of a high-definition image on a flat-panel TV and another displayed on the same screen at 1/10 the resolution. The basic image may be there, but the missing detail makes it less enjoyable to view (or in some cases hard to make out).
Fortunately, iTunes makes the compression issue a simple problem to solve.
Changing the iTunes defaults for better sound quality
iTunes has a default import setting of 128 kbps. This setting affects tracks ripped from CDs, as well as sound files imported from other sources, such as audio editing programs. It does not affect music purchased from the iTunes store. Downloaded iTunes tracks come in at the resolution they're sold at (currently either 128 kbps, or higher-quality 256 kbps files).
Even if you get most of your music through iTunes store purchases, changing the default import setting for music from other sources is still a good idea. And it's easy to do.
Just go to the "Preferences" menu (depending on which version of iTunes you're running, it could either be under "Edit" or "File"). Then go to the "General" setting. You'll see a button labeled "Import Settings." In older programs you might have to go the "Advanced" tab, and then chose "Importing."
Either way, you'll soon see a choice of file formats. Some of the formats give you a choice of resolution. Don't worry about remembering numbers — Apple's helpfully labeled the choices with phrases like "Good Quality" and "High Quality." Below, you'll see the format choices you'll be offered, in descending order of sound quality. If you're not sure which format will give you the highest sound quality you can hear, try a simple test. Import the same track with two different settings — listening to them side-by-side can be the best way to determine which format works best for you.
WAV files are the largest in size, because your CD tracks are ripped with no compression. While this is good from a sound quality standpoint, there is a disadvantage — you won't be able to attach album art to these files.
AIFF files are Apple's version of a WAV file, but they allow a little bit of room in the file for metadata. This means you can attach album art to an AIFF file.
Apple Lossless files store data more efficiently than either WAV or AIFF, and have virtually the same sound quality while taking up about half the memory.
AAC is Apple's proprietary file format for audio. Songs purchased from iTunes are AAC files.
MP3 files are similar to AAC, and both compress music about the same amount, while using slightly different algorithms to do so.
Whether to use AAC or MP3 is a personal choice. Some people hear a difference between the two, and both have their supporters. One advantage to the latter format is that you can transfer MP3 files to non-Apple digital music players.
The MP3 and AAC settings also let you select compression rate, conveniently labeled "Good Quality," "High Quality" and "Higher Quality". Or you can use the custom setting to enter in a different sampling rate, including ones that are either higher or lower than the offered settings. Remember that not everyone notices higher sound quality with a larger size file. If you don't hear a difference between a 192kbps (higher quality) and 160kbps (high quality) MP3 file, then by all means go for the lower file size.
Upgrading older files
Changing the default settings takes care of any tracks you import going forward, but what about all those songs already in your library saved at 128 kbps? It isn't possible to "upscale" older iTunes files. If you want higher bitrate versions of those older songs, you need to import them again.
iTunes recognizes when an imported track is the same as one already in your library. It will give you a prompt, offering you the choice of either loading the new version and keeping the old, or replacing the stored file with the newer one. And when iTunes does replace a track, it transfers any metadata attached to the older file (year of release, beats per minute, play count, and so on). This means you don't have to re-enter all that data, and the play count doesn't reset to zero.
A word of caution — iTunes gets its album information from the Gracenote.com database. Users from all over the world continually upload track information to Gracenote, and sometimes a CD's information gets revised. If the track information has changed, when iTunes autofills the tracks it won't always recognize the song you're bringing in as the same as the one you want to replace. iTunes only offers the overwrite option if there's an exact match.
Getting rid of the duplicates isn't much of a problem, though. Make sure you have your main music library selected. Then under either the "File" or "View" menu (depending on the iTunes version you have), select "Show Duplicates." iTunes looks for matches in song titles and lines up the tracks very nicely one under the other. Simply chose the version you want to keep, and delete the other (of course, you'll have to re-enter all the metadata again for the new addition).
Moving your library to a larger hard drive
Less compression equals higher sound quality. But it also equals larger files. Even if you keep your music files relatively small, it's pretty easy to clog up a computer's hard drive with music. The easiest solution is to transfer your library to an external hard drive. And because the cost of these devices continue to fall, you don't need a fortune to get an external drive large enough to comfortably house tens of thousands of high-resolution audio files.
Relocating your iTunes library to an external drive is fairly straightforward. Start by connecting your new drive to your PC through your computer's USB port. In the iTunes "Preferences" folder, select the Advanced Settings. Under the "Advanced" tab (sometimes "General" tab in earlier versions of iTunes), there's a place to change the iTunes Music folder location (make sure both "Keep iTunes Music folder organized" and "Copy files to iTunes Music folder when adding to library" are checked).
Using the "Browse" function, select the new drive and hit "OK." This changes the default location of the iTunes music library, so that everything you add to iTunes from that point forward will go straight to the new drive.
The final step was to go to the iTunes "Edit" menu, and select "Library." From that drop-down menu, choose "Consolidate Library" (older versions have this under the "Advanced" menu). This starts iTunes copying its library to the new drive. The nice thing about this process is that all of your music's metadata is preserved: play count, album art, year of release and so on.
Since this creates a copy of your library, you can check to make sure the transfer worked before deleting the library off your computer's drive. When you're ready to clear the iTunes library off your PC, be careful to delete the music the right way. You should only delete the actual music files inside the iTunes folder (it's the one marked "iTunes music" and has the artist folders in it). In order for iTunes to function, the other folders need to remain untouched.
When you're finished, you'll have room to grow your iTunes library without stinting on sound quality, and your computer will probably run a little better as well.
Moving your library off a laptop
While the process for moving your iTunes library is the same for both a laptop and desktop computer, there are a few additional things to consider with a portable PC. Chances are you'll be plugging in and unplugging the external drive as you move from location to location.
If you leave iTunes open and disconnect the external drive, iTunes will reset itself to make the laptop's C drive the default library location. Although all the songs remained listed in iTunes, if you click on any, an exclamation mark will appear in front of them to denote an unknown address. Any songs you import while the external drive is disconnected will be stored in the laptop's memory.
When you reconnect the hard drive, you'll have to go into the iTunes "Preferences" menu and then to the "Advanced" tab to change the address of the library back to the folder on the external drive (you can find this under the "Advanced" menu in older versions). Select "update" and wait a minute or so while iTunes reestablishes all the connections between its listings and the music files on the external drive. Any new music you imported remains stored on the laptop.
iTunes will also reset its library location to the C drive if you open the program before connecting the external drive to the laptop.
Fortunately, there's a simple work-around that avoids all that: just remember to close iTunes before disconnecting the external drive and open it only after reconnecting the drive. As far as iTunes knows, the connection between it and the external drive was never broken. You won't have to re-establish file links and any new additions will automatically go to the external drive, where they belong.