It's not your player's fault. I am still experimenting with the combo feeds and time synchronization. When two frequencies are combined on the controller end, and the two individual feeds get out of time sync by even a fraction of a second, echo results. Trying to work on a way to fix it, but it could take a little while. In the interim you can listen to either one of the two separate feeds, or perhaps open two players. This will eventually be fixed.