In addition to its support for external sources, the DEH-P6000UB can handle several audio formats on CDs including MP3, WMA, AAC, and WAV. When playing digital audio discs, users get plenty of choice for what shows up on the display: by pressing the DISP button, they can show each of the following readouts: playtime; folder and file name; artist and track title; artist name and album name; album title and track title; track title and play time; artist name and album title; or comment and play time. If that is not enough options for you, there is also an indicator to show the current bit rate or sampling frequency of compressed audio discs. The DEH-P6000UB provides an easy-to-use interface for navigating folders and files on compressed-audio discs. A press of the list button brings up the top line menu of folders, which can then be scrolled through (by rotating the scroll wheel or by pushing it up and down) and either played in full (by pressing and holding in the multicontrol wheel), or opened up to provide a list of tracks (by pushing the wheel over to the right). Once a track is playing, users can skip forward and back though tracks (by pushing the controller left or right), or back and forward between folders (by pushing the controller up and down). In general, the search and control functionality for compressed audio discs and audio on generic USB devices is straightforward and intuitive.
The DEH-P6000UB has features for tweaking and enhancing the quality of audio output once it has been selected. The system's headline feature is its Advanced Sound Retriever technology, which is designed to enhance compressed audio by restoring sound lost in the compression process. ASR works only on MP3-, WMA-, and AAC-encoded discs and can be set to one of two levels depending on the amount of artificial harmonic restoration required--typically, audio encoded at a lower bit rate will require the higher ASR level 2 setting. In practice, the ASR technology serves to give compressed audio tracks greater depth and richness.
Parallel with the ASR settings, the DEH-P6000UB has a seven-band equalizer, which can be used to tweak audio of all formats. The system comes with seven presets including two custom EQ curves and an "S.Bass" setting, which enhances low-end output. Other useful audio-tweaking features include source-level adjustment, which lets drivers assign volume levels to individual sources; separate controls for turning on and selecting the level of the subwoofer; and a high-pass filter for diverting all low-end sound below a certain frequency to the subwoofer. No matter how you have your EQ set up, the DEH-P6000UB provides a robust sound thanks to its built-in MOSFET amplifier (14 watts RMS/50 peak x 4 channels), and those who want to upgrade this can take advantage of three sets of 4-volt preamp outputs . The system can also be turned into a satellite radio receiver or a Bluetooth hands-free calling interface with the addition of external modules.