A few years ago, I started working on a whistle pack for thelocoshop's N&W 611. I'm just about finished with the pack, but I am having an issue with some of the whistles that is getting on my nerves. Sometimes, when I stop blowing the whistle there is a noticeable click or pop between the transition from the WhistleLoop and WhistleEnd files. However, this isn't consistent. For some blasts the transition is seamless, but for others it is abrupt. I've tried every editing trick I can think of, which helped fix most of the whistles in the pack. But, a few whistles have proven to be more troublesome. The clicks and pops can't be heard from a distance or when the locomotive is moving, but are obvious when the locomotive is stopped.
Here is a video of my problem. https://www.youtube.com/watch?v=uYXnLJ1OwiI
Notice how in the first crossing sequence, the whistle pops at the end of the first, third, and fourth blasts. In the last crossing sequence, it pops at the end of the first two blasts, while the others are perfectly seamless.
Is there anyway to make the transition between the the loop and end files smoother? Is there something in the blueprint that could crossfade the two files? Thanks in advance.