Shame that Philips did not try to optimize these headphones. Originally, they do not fit enough into the ear of the blow pipe, they tend not to remain in place but especially the bass is almost absent. So has less keep a constant finger on each earpiece to support, the sound is really bad. Practitioner model, so I modified these headphones by adding a piece of 4mm aluminum tube diameter and 1 cm in length on each item, and 2 silicone ear headphones sony has put a stick and the end of each tube (not easy but doable). After this mod, the bass is well with sharp one can back but overall the result is very satisfactory, and mostly they stay in place. Hope for new models there will not be a change made.
