For the past year I have been using a pair of stax lambda pro electrostatic headphones with my Copland 288 cd player in one of my setups. I sold my Martin Logan speakers and wanted something as good but more suited to a small room, able to be used any time of day or night and as loud as I wanted with minimal external noise. Quality headphones are very hard to better with similar priced loudspeakers. They also provide a highly involving listening experience. Their diaphragms are much lighter than typical dynamic speakers and so have timing and pace unmatched bar the very best speakers. Electrostatic speakers do try to overcome this problem by the use of lightweight film which only weigh a few mg. Dynamic coil based systems have the weight of the coil and cone to move, including mechanical resistance from the 'spider' and surround.
Pace and timing are important to keep the listener hooked. A Hi-Fi system can have superb detail, width and depth and be very Hi-Fi sounding but I've heard setups including my own at various stages that still sound boring, lacking rhythm and pace. Headphone lightweight drivers go along way to solve this problem.
So the pull of using headphones like the stax drove me to try a dynamic design. I remember hearing a pair of Grado GS1000 when I had a pair of Sennheiser HD580 and was stunned by them at the time but could not justify buying. Grado's are priced higher in the UK compared to the USA.
The PS500 have the on ear L cushions (L-cush) and I wear glasses so these could be an issue regarding comfort and it turned out as such. I could only use them for 30 minutes before it got too much. In the end I ordered a set of G cushions (G-cush) designed for the PS1000 and GS1000 since I knew these would also fit the PS500. Fitting is very easy but the new pads do alter the sound. I have read on headfi that some consider the PS500 worse with the G-cush whilst other prefer them as they bring them closer to the PS1000 sound for less cost. I am in this later camp. With the G cushions fitted they are very comfortable and I would no longer consider buying any Grado headphones without these pads fitted either as standard or as a mod.
I listened to the PS500 using both my Yamaha AS1000 headphone output and a Yulong A100 Class A headphone amplifier comparing them to the stax pro. For the first 50 hours from new the PS500 are very bright and edgy sounding. They need to be run in. Mine are now over 6 month old and the sound has changed. They gradually loose the bright edginess over time but even after a basic run in period of a few days they are very usable. I listened to the headphones with both the L and the G cushions.
The sonic difference between the L and G cushions involves the bass and sound-stage. The L-cush has a more punchy forward bass compared to the G-cush which is a little further back and lighter sounding. After using the L-cush for as long as I can stand, switching to the G-cush the bass initially sounds thinner but I don't think it is worse. If anything the L-cush bass can be a bit much on some material as it is too forward and not relaxed enough in the overall mix. The G-cush opens up the soundstage which I think is a very good trade off from the in your face punchy bass. It depends on what kind of sound you prefer.
The PS500 are very revealing headphone. They will show any flaws and faults in the recording but will equally bring out lots of micro details normally difficult to hear in a mix. I can easily ignore most minor recording flaws if the music is good but some people become fixated on faults. These cans would make good mastering headphones for musicians and studio work.
The PS500's are better than my stax lambda pro electrostatic headphones in terms of extension, transparency and detail. The older stax are quite dark and a little nasal in comparison. Just a pity the UK prices of Grado are not in line with other parts of the world so not a bargain at the RRP but if you are ever in the states and can find a pair you could grab them for less than UK cost. The Stax however still beat these in terms of relaxation, long term easy listening and shear spaciousness due to the stax's diaphragm size. Maybe the larger PS1000 and GS1000 drivers might come closer to the stax soundstage but I don't have these other Grado's to compare. Certainly using the G-cush gives the PS500 a bigger soundstage at a slight loss in bass punch so this is well worth trying if you are on a budget.
So if you want a set of mastering headphones or something that is very revealing and detailed then these are up there with the best. However if you want something a little more relaxing with a wide and expansive soundscape then maybe these are not the ideal choice and the GS1000 or PS1000 would be better.