Earbuds and speakers with Sena
I have a Sema SMH10 and have used both the helmet speakers and the earbud route. I found that on the highway even behind a windshield that the only way to hear the speakers was to not use any ear plugs. That is not acceptable, so I also bought the optional clamp and use it with Etymotic ER6 earbuds. They have good noise isolation in the mid 30's and great sound. However, like all earbuds they are a PITA so I only use on long trips for music and hesitate to remove my helmet and go through the whole process of putting them in, having the helmet pull them out etc. i may try custom fitted buds with a lower profile although the wires will always be in the way.
The biggest issue is that I often want to use the intercom or phone when at slow speeds, recognizing that it is without ear protection. I therefore installed two Sena clamps, one on each side of the helmet. One uses speakers and the other the buds, and there are two mics. Riders have been all over Sena to make a combo unit but they will not.
On my new Neotec I may just install the earbud setup and not use Sena when I just want to use regular non speaker earplugs.
I was very interested in the gel earcups as that is something that I was considering. Too bad it is not enough.
BTW I have almost always used earplugs and have also lost hearing at the higher frequencies anyway.