yes Formant passes only speech. Good for car environment while driving.
The 1.8 filter does not rely on DSP. It is 'hard filter'
The truth is that initially I asked a more veteran ham to do the soldering, but then I got impatient and did it myself.
I also solder the TX-O stability Crystal. that involved cutting two wires, the first which flew into the radio and it took me 20 minutes to fish it out. One the second cut I was already more experienced.
so far I tried all DSP settings and none makes anything better. The only thing that makes a difference is the IF filter which is on/off.