so this has been bugging me for about two weeks now. my ic-7300 was working totally fine and then one day i keyed up on the local 2m net (yeah i know, using the 7300 for 2m via the transverter) and dave k4something said my audio sounded completely muffled, like i was talking through a pillow. checked my mic gain, compression, all the usual stuff on the menu and nothing obvious jumped out at me.

swapped the mic to my backup heil pr40 setup and same deal. so its not the mic. pulled up the scope on the radio to look at the waveform and it looks... off? like the highs are just gone. i dunno how to describe it better than that. almost like a low pass filter got engaged except i didnt enable anything like that.

i did update the firmware maybe three days before this started but im not sure if thats related or just coincidence. anybody dealt with this on a 7300 or similar? wondering if a cap somewhere on the audio board is going soft or if this is something dumber that im overlooking

first thing id check honestly is whether the TX bandwidth setting got changed somehow, on the 7300 you can set it under the mode settings and if it got bumped to narrow or something like that it would absolutely kill your highs and make you sound like you're in a fish tank. go into the set menu and look at the tx filter settings, bet thats it. firmware updates on icom have been known to reset some of that stuff to defaults.

if thats not it then yeah could be hardware, ive seen electrolytic caps on the mic amp board cause exactly the kind of degraded audio you're describing, especially on rigs that are a few years old and run warm. but start with the software stuff first before you crack it open, save yourself the headache

had something weirdly similar on my 7610 last year, ended up being the TX monitor was misleading me and the audio was actually fine on the air lol. not saying thats your problem but worth having someone do a real recording of your signal before you go too deep into diagnosing it. kinda embarrassing how long i chased my own tail on that one. anyway if it IS a real issue the filter setting thing the other guy mentioned is the first place i'd look too