Obviously the Grado isn't only the brand you can play with and experiment. Purchasing P5 might not solve the sibliance problem or even make it more revealed which none of us know for now.
Jaytea has the right point of steps you should go through to resolve. I'd only add to check stylus/cantilever wear.
Jaytea has the right point of steps you should go through to resolve. I'd only add to check stylus/cantilever wear.