so ive had my 891 for about two years now and overall really happy with it but a few guys on my local net keep telling me my audio sounds a bit boxy or something. i messed with the parametric EQ settings in the menu which helped a tiny bit but i keep seeing references to this hardware mod where you swap out a capacitor on the TX audio chain to open it up a bit. i think it's C211 or somewhere around there but i cant find a consistent answer on which component it actually is.

has anyone actually done this on the 891 specifically? not the 857 or 897, those seem to have different threads everywhere. i can solder fine and i have the service manual so that part isn't the concern, just not sure if the payoff is worth cracking the case open. also wondering if it affects the SSB transmit bandwidth in a way that would put me outside of regs or if it just affects the tonal quality. anybody have before/after audio recordings even?

yeah i did something similar on mine, though i went down a bit of a rabbit hole because the service manual revision i had didnt match where the component actually was on the board. took me longer to find it than to actually do the mod. the cap swap does open up the low end noticeably, my signal reports went from people saying it sounded like i was talking into a soup can to actually sounding like a real voice lol. i dont think it pushes you outside regs because youre still filtering at the IF stage, the mod is more about the mic input chain before that, but honestly dont quote me on that because i never actually measured it. i just went by what guys were hearing on the air. if you have a service monitor or know someone who does, worth checking the spectral plot before and after just to be sure.

the 891 audio mod threads on eham and qrz are kind of all over the place, some people are talking about different revisions of the board so it gets confusing fast. what might actually help more than the cap swap honestly is pairing a decent dynamic mic with the right impedance rather than the stock mic. i swapped to an SM-58 with a little interface cable and the difference was bigger than any hardware mod i tried before that. still worth doing the mod eventually if you want to dig in but sometimes the gain is sitting right there at the mic end and its cheaper to start there. just my take.