A few years back it was fashionable to use ‘HiFi SSB’. The idea was to transmit a much wider AF frequency range with the emphasis on getting more bass response. I remember hearing a station who was proud of his studio mic and loads of processing gear. His signal had lots of bass and extend higher frequencies. His bandwidth was nearer 8Khz than the usual 2.4Khz. He said he did not care because he had spent a lot of money getting ‘better’ audio.
Years back I was taught that the frequency range for intelligible speach was 300hz – 3.4Khz. I find that lots of bass makes signals harder to copy, especially when they are weak. Which is exactly why the military and aviation communications limit the bass response.
Why spend lots of money on expensive ‘studio’ microphones and other fancy audio stuff when all it does is make your signal less readable? Is it the just the dealers making money again? Is it the desire to be different/better that other ops? Or is it a lack of understanding of what radio communication is about?