That is the whole point of 24 bit audio files, you get 144dB of dynamic range with uncompressed sound, if they were to master it any louder they would have to use compression. I have experimented creating binaural recordings and mixes with compression and it always compromises the spatialization effect; basically, compressed acoustic instruments sound unnatural, especially in 3D. Probably why binaural music never became popular.
I love the binaural touch, but does anyone else think that the Chesky albums are all produced with too low of gain? The volume, compared to everything else in my library, is extremely low. I understand that contemporary music can be produced louder due to the loudness war, but the Chesky works are exceptionally low.
Perhaps Chesky could comment on why he chose the output / input levels of the albums?