Along with seating choices, it's important to note that your facial expression can have a profound effect on sound...try various expressions like ennui, horror, open or closed mouth (this is very tooth dependant..."extreme overbite open mouth" will reflect treble up your nose), waxing nostalgic, disgust, etc., and regardless of your state of mind try to remember what expression sounded best and keep that for your listening session. Leather chairs are great, but avoid those made from fish skin as they get pretty smelly in warmer weather if not cured properly. Dental chairs have small headrests and the advantage of height adjustment, and often can come equippied with the little water bowl for expectorating. The drainage hookup can be a hastle, but for anyone who has ever thought, "I hate to have to interrupt the Sneakers soundtrack just because I have to jump up and spit" it can be handy.
