Personally, I take these graphs with a grain of salt. If you just go by looking at the graph below, you'd think the PS500 is a bassy, treble lacking performer. FAR FROM IT. With the right source feeding it, the reproduction is as close to any musical instruments that I've ever heard through a headphone. I don't hear anything that indicates coloration.
If you hear the 225 in comparison, the bottom end is severely lacking and the upper mid and treble is bordering harsh. It was not until I experienced the PS500 did I realize how skewed the 225 is. They are not a good representation of what you actually hear from a musical instrument. In all honesty, I won't keep them as backups as I now find them so badly lacking. Sad but true.
I've been listening to Alison Krauss and Union Station, Paper Airplane, a modern recording with top notch mastering. The dobro and dreadnaughts sound much more like the real thing on PS500 than 225. Alison's vocals are absolutely breathtaking and reproduced spot-on, not a hint of harshness. The graph's means absolutely jack diddley squat to me. If the RS-2 is indeed that close to the 225 in the upper register, as the graph indicates, I am really glad i skipped over them, but something tells me that the "graph" will misrepresent those too. According to the graph, the RS2 and 225 look nearly like similar performers, but we all know that isn't the case.
The PS500 really has to be heard to be appreciated, I can't stress enough how much the source will impact the sound. I've been playing with multiple sources the past week.......big differences heard between all. A good transport with correct implementation will make the PS500 an absolutely breathtaking experience.
Equipment: Pioneer DV-58AV, Onkyo DV-SP506, Pioneer PD-F1007, Pioneer DV-610, Cowon J3, Cowon D2+, Logitech Touch, Logitech SB3, Dell Laptop (POS model), Emotiva XDA-1, Little Dot I+, Schiit Asgard.