If I want to listen to something critically, I'll hunt down a hi res flac or alac file, use a good quality cd or SACD or I'll use my turntable. If the stuff wasn't there in the first place, it's hard to hear it on playback no matter the file (at 256 and above). However, on many recordings, I'm very hard pressed to hear any difference all. It is however filled with micro nuances to existing notes. That sheen is not filled with 'hitherto unheard notes'. When I play the same piece if music at 256 and in lossless, I often find that there is a slight but palpable loss of what I think of as a sort of sheen to the music. Other sources are a recently significantly upgraded CJ Walker turntable and an Oppo BDP 95 disc player. I use Revel Ultima Salon 2 speakers backed up by an Ayre V-5xe amp, Ayre preamp, Acoustic Research DAC8 and an Aurender N100H as a source. I think that I have a pretty good audio system. The difference may be between afternoon and dinner time. This sort of stuff is harder to verify, requiring double blind tests and the opinions of hopelessly fallible human beings. However, it is said, bitrate of the encoding used on iTunes files imparts no human-perceptible loss in the audio when compared to the source CD material. wav format to match the bits on a CD, the expanded bits from the AAC file would not match perfectly with the bits on the CD because of of the lossy encoding. The encoding is a lossy encoding so from a purely bit-wise perspective the content sold in the iTunes store is not 100% identical to content from a CD - when expanded back to a. Is this quality comparable to that of a lossless file or CD? The actual sample rate is varied dynamically based on the content and time. The 256 kbps setting is an average bit rate encoding scheme, not a fixed bit rate encoding scheme. That marked the debut of DRM-free music tracks encoded at a higher quality bitrate that Apple claims is virtually indistinguishable from the original recordings.Īs of 2007 the audio files sold in the iTunes store have been encoded using the Advanced Audio Coding (AAC) codec and distributed with. Music encoded as 256kbps AAC files first came to the iTunes Store in 2007 with the launch of Apple's iTunes Plus.