Digital Audio

Your computer can make a great music player for headphones, but it can seem a bit of a daunting task given all the choices you must make. 

Headphones.com would like to lend a hand and give you some basic advice.

Digital USB Music Can Sound Surprisingly Good!

Audio is a sonic chain that starts in the studio when the music was initially recorded. The chain ends in your ears through a pair of headphones or speakers.

For computer-based digital audio, a good DAC can turn your computer into a high-end music source.

You can learn a bit more about what a DAC is and how it works by reading What is a DAC? Simply put, a DAC is a digital to analog convertor that turns all those 1's and 0's into an analog signal that we can listen to.  Every computer has a DAC behind the headphone jack, because its necessary to listen to music! 

An outboard—separate from the other components—DAC unit contains excellent components and is specifically designed for extracting digital audio as accurately as possible.  DACs and headphone amps are often combined into one unit, but not always. They can be connected via USB, AES, or optical connections, with USB being by far the most common.

How to Use a DAC

Hooking up your computer for USB music playback is accomplished by simply hooking up the computer to any DAC device with a USB cable. Caution: this connection should be made before launching the music player application or the DAC may not be recognized. Simply close and re-open the application if needed.

Every once in a while, a computer doesn’t automatically recognize the DAC via USB and you must manually configure the computer hard-drive to use “USB Codec.” Here's how:

On Windows machine: Go to Start Menu > My Computer > Control Panel > Sounds and Audio Devices > Audio (tab) > Sound Playback. Look for "Audio Default Device," pull the drop-down menu and select “USB Audio CODEC", then OK and Apply!

On Apple Computers: You may have to select the DAC the first time you hook up your MAC computer to any DAC; after that, the computer will automatically select the DAC whenever it's plugged in unless you manually de-select it. To select the DAC, go to System Preferences > Sound then choose your DAC. Remember, the USB DAC or optical connection must be plugged into the computer for this selection to appear.

Apple iPad: By using the Apple 'Camera Kit' - essentially a USB output adapter - audiophiles can make the iPad a true digital-output portable player ready for serious sound quality improvements via USB feed into any DAC + headphone amp. When you use this kit, selecting the DAC will depend on the player you use, but all of them should have easy-to-find options for selecting output devices like DACs or DAC/amps.

Digital File Formats

There are numerous file formats for computer audio. However, there are just three that we can recommend without reservation as they are universally compatible now and for the foreseeable future with digital music players. They also do not have any digital rights management (DRM) features that may make them difficult or impossible to copy and play.

.wav – Wav files are typically uncompressed (bit-for-bit) copies of the music data on a CD, and will sound just as good from your computer as they do from your CD player when using the USB out to a DAC. The size of these files are typically 10MB per minute of music, so each CD will normally consume about 700MB on your hard drive.

.mp3 – By far the most common way music is stored on computers and portable music players. This is a “lossy compression” format, which means that the stored music is not a bit-for-bit perfect copy of the original. A complex algorithm is used to reduce the amount of data it takes to store the music. The advantage is that it takes less hard drive space to store your music and can be used on virtually any device and media player.  The disadvantage is the quality of audio can be reduced depending on the encoding bitrate selected. We highly recommend bitrates of at least 256 kbps and preferably 320 kbps without variable bitrate encoding (VBR) turned on. A CD stored with 320 kbps .mp3 files will use about 170MB of space on your hard drive.

FLAC-  FLAC is an uncompressed audio file format that is open source and available on Windows and Linux machines.  FLAC provides lossless audio and takes up only about 50-60% of space compared to a normal lossless file.  FLAC cannot be played back on many media players, particularly iTunes, without some third party apps.

If you’re a dedicated MAC, iPhone or iPad user - and are willing to accept that the following file formats may not be playable on some non-Apple hardware - there are two more formats worth considering: .aif and .aac.

.aif – Call it Apple’s equivalent for the .wav file, this lossless format will deliver bit-perfect audio at about 10MB/minute. Get plenty of hard drive space for your library to use this format, as the file sizes will be quite large.

 .aac – Apple’s 'better sounding' equivalent to the .mp3 file. We recommend using the bitrate settings 256 kbps and above, or 320 kbps when you can rip it yourself. While this format sounds better at any given bit rate, it can also be encumbered with digital rights management (DRM) features that limit the use of the file, meaning you may not be able to copy the file from one place to another easily.

To Compress or Not to Compress?

Hard drive space is quite inexpensive these days, so there is little penalty for storing all your music in uncompressed .wav or .aif files for your home system. However, since it lets you put four times as much music on your portable player we generally recommend high bit-rate .mp3 or .aac files for your music library if you’re going to be using a portable player regularly. If you’re comfortable with your music management software, however, you may want to create two separate libraries of computer music files, one uncompressed .wav or .aif files for home, and one of .mp3 or .aac files for use with a portable player.