Animagus
Reviewer at Twister6
That looks like a good opportunity to use another dynamic drive. The rise on the L9 I think starts about 400-500hz. But the problem with the L9 bass is that slow attack/decay that doesn't keep up with the BAs and bleeds a little into it.
These Sonion EST is kinda different technology and it has it's own power converter integrated. On paper, it shouldn't be need a strong source of power to drive it.
Sonion EST drivers are actually electrets and not electrostatics, so they do not need as much power.