I have had two unforunate occasions that I have broken off the connection point where my ear buds plug into the Sena base unit. To solve this I purchased the base unit with the speakers and cut off the speakers, soldered the leads together to a female plug. In my case I now have two base plates with this arrangement. One has a length of about six to eight inches so it can reach my inside jacket where I can plug into a "Y" cable that allows me the ability to connect to various devises.
The other cable on the other base which is on a different helmet is shorter for when I'm only plugging in my ear buds and using bluetooth to connect to my phone and Garmin 665.
This idea may work even better in colder climates where plastics become brittle in the cold.
Since using these modified style of bases I have not had one failure.
Just an idea that worked for me that I thought I would share.