Tracks were carefully chosen to represent a wide listing of genres – subject, of course, to the reviewers listening preferences to ensure familiarity with the nuances. We tested all PMPs with tracks encoded using dBpoweramp Music Converter V11.5. This is one of the best audio transcoding software available mainly because of its accurate, error-free encoding. The source files were FLAC and these were encoded to MP3 using 320 KBps and the preset setting ‘very high’. We used a reference system and noted nuances of the tracks that were then listened to on each PMP. The reference system was thus:
Source: ASUS Xonar Essence ST
Amplifier: Little Dot Micro Tube
Headphone: Grado SR 225
We rated each PMP using the Grado SR 225 headphones to give every PMP a level playing field. First we rated each track based on the sound reproduction, and after that rated each player on their abilities at different aspects of sound i.e. bass, treble and midrange. We also rated the respective soundstage effect. After this each player was tested with its earphones and the quality was rated against the quality of sound on the Grados. For the video component we used AVI files and encoded these using MediaCoder at the two resolutions. The first was 320 x 240 pixels to give each player a level playing field since this was the minimum resolution that all video PMPs supported. The second encode was at the maximum resolution that the respective PMP supported.
Besides rating the players on their performance we also gave points to the menu system and layout, usability and interface of the device, features such as the presence of document readers, alarm clock, stopwatch, contacts – basically PDA-like functions. We also noted the PMPs support for various image, video and audio formats as well as player features like custom playlists and number of preset modes. Additional features like Bluetooth, built-in speakers and use as a portable drive were also noted