About the seal, it totally makes sense. I bought the Byron BTs to be my gym set. I wasnt expecting anything riveting out of them but my first couple of uses with the stock silicone tips let me feeling completely ripped off, they were thin, hollow, anemic - awful really. I put a set of comply foam on them, and oh my, the sound was night and day different. I mean they were still BT iems but for active listening, riding a bike, working out or messing around in the yard, they were perfect. I sold them last week. But I learned about the monumental difference tips can make. I've been hearing alot of really great things about the Final E-Series tips so in anticipation of the Xelentos, I picked up a set. I was pretty convinced that Foam was the way for me to go, but these E Series have changed my mind on that too.... I actually like silicone now, who would have thought. Thanks for you input.