- Aug 31, 2005
Coming from ER-4 I'm sure is a big difference, but I use the K3 Pro's at the gym with a moderate (not blasting my eardrums, lol) amount of volume, and for me they isolate the same as W30, W4R, or some of the newer KZ models like ZS-5 or ZS3. I would suggest Symbio tips or some type of foam like comply if you need more isolation. There aren't many IEM's designed like ER-4 that require a deep insertion depth. In my experience with the K3 Pro, the shallower insertion the better the sound. Just my opinion.