This caused untold misery on my recent 2k mile trip. Siri comes through loud and clear at speed when asking for directions. Then inexplicably, as soon as the directions start, the volume drops to about half and I cannot hear the directions. This only happens when I am connected to the 10C EVO. When I am not connected and have Siri at full volume, using the phone speaker, the directions are at the same level as Siri. The drop in volume only happens when using the 10C, which makes it useless for navigation. USELESS. I have tried settings in the phone and on my Sena. I have the Sena volume boost on and still nothing works. Very frustrating. I don't know if this is an iphone issue or a Sena issue. I don't remember this happening with my Android. Has anyone else had this problem?