I did some modification on my HM-198 used with the IC-7000 since somebody told me audio is not so well on higher frequency.
This modification is not tested on the bands ! 04.05.2016 !!!
July 20. 2017: the modification ist tested on HF, VHF, UHF "good modulation.."
Attention: The HM-198 is not original mic to the IC-7000!
I found a 10€ headset at local radio shop and made a adapter box to use it for my Kenwood TS-570 and TS590