Maybe I can sneak another (somewhat off-topic) dome question into this thread rather than reviving an old thread and notifying all the posters in the old thread:
If one is going to try a power dome vs. an open dome, how does one figure out from the size of the open dome what size of power dome might fit best? For ReSound, the open domes and the power domes don’t seem to be the same diameters. Should imagine the power dome compresses less so that one would probably want to try a slightly smaller size power dome than for an open dome. Was going to try without running to audi for refitting due to venting difference, etc. For tulip domes, I see (at least for ReSound) that one size fits all.
EDIT_UPDATE: In the fitting software, the ReSound open domes and the power domes have the same size designations so I just ordered one set of 7M power domes as I currently use 7M open domes. If the ReSound Surefit Receiver and Dome Guide is done to scale, they do appear to be different sizes with the open domes being slightly larger.