Doesn't look that way to me. I have both the T400 tips on me and the bore is the same size. The only real difference between these tips is that the large TS200s are a little wider which allows for me to get a seal on my IEMs. While the T400s I'll actually rely on the IEM housing to achieve a seal (Sennheiser IE8).
Edited by lee730 - 7/15/13 at 6:30pm