I recently replaced a worn out pair of Shure SCL3 IEM's with a new pair of Shure SE425's. The sound quality of the new IEM's is definitely better, but I am having an issue getting proper sound isolation with them.
I had been using the triple-flange sleeves with the SCL3's because I found they gave the best isolation of all the ones that come with the product. The same type of sleeves that come with the SE425's do not seem to offer the same level of isolation, probably because the design of the SE425's do not allow for deeper insertion into the ear cavity like the design of the SCL3 did.
Any suggestions? I am hesitant to try custom molds again. I had a pair made for the SCL3ís. Sat for the fitting with my audiologist, and ordered them from Westone, but they never sealed right, so I just kept on using the triple-flange sleeves.