I'm trying to get rid of microphonics. Customizing it with Fisher a good idea? I called and they said they would do it. Any other places customize ER4s? Also, do you guys actually believe in better sound through more isolation with either custom tips or full customization? I can't see it getting any more isolation from it as ER4P has a perfect design for isolation since it goes deep inside ear canals, and with triple flange, it isolates like no other. Only benefit to customizing it is for microphonics to have the wire go behind the ears more naturally.
I don't know man, I'd be a little weary of customizing the ER4s. I think much of the SQ of the ER4, and part of the reason it has such a uniquely-accurate SQ, is due to the specific way in which they're seated in-ear. You'd be surprised how such little alterations in positioning/ tip material/ bore diameter/ filters play such a huge impact on the overall sound quality. I guess it'd work, but you'd have to be really sure that you're getting excellent isolation/fit, w/ details such as bore diameter/filtering as close as possible to stock ER4s. Even so, I would expect the sig to change w/ any type of re-shelling.
I'm not sure of the exact thread, but I remember someone on this board posting about how he had his ER4s remolded (by Fisher I think,) and he was incredibly disappointed in how much the SQ had been altered afterwards. He even commented in how crucial that deep-insertion (yes, I said it) is to the performance of the ER4s.
Let me know how it goes if you give it a try though. I'd be very interested in photos too.