Bought a Savage open-face helmet last year as addition to full-face Shoei with SENA 10U installed.
Savage worked OK for slow riding on naked bike, but wind noise exceeded speaker volume at 50+MPH. Contacted SENA for support, but no simple solution - helmet fit is good, no optional side pads available, no speaker upgrades.
So I solved the problem with hack: removed the SENA speakers, clipped the original speaker wires to re-use proprietary connectors, determined wiring polarity and proper grounding, and soldered in a stereo 3.5mm headphone socket for use with in-ear monitors (IEM).
I'm using special high impedance IEMs with 260 Ohms each side. High impedance reduces load on the SENA amplifier for safe operation.
Result is excellent sound, great noise isolation, easy conversations using the Savage's built-in brow microphone. Modification recommended if your Savage sound sucks!