so ive been on HF for about two years now and i keep getting reports that my audio is kind of muddy or 'bassy' and honestly i cant tell because it sounds fine to me on the monitor. running an IC-7300 into a Heil PR-40 which should theoretically be a pretty solid combo but something isnt clicking.

i messed around with the TX bandwidth settings and the bass/treble in the menu but i feel like im just turning knobs without really understanding what im doing. a guy on 40m last week told me to cut below 300hz and boost around 2-2.5k and it made a noticeable difference but i dont fully get the why behind it. is it just about fitting the audio into the SSB passband better or is there more to it than that

also should i be using ALC at all or is that something to avoid on voice. i know for digital modes its a whole different thing but for phone i genuinely dont know what the 'right' approach is with ALC and mic gain. feels like every time i read about it i get a conflicting answer

the 300hz cut advice you got is solid, thats pretty standard stuff. SSB passband on most rigs is roughly 300 to 2700hz or so, sometimes a bit wider, and the low end frequencies below that dont really carry intelligibility anyway — they just eat up power and can cause splatter if youre not careful. cutting the mud down low and bringing up that 2-2.5k presence range is basically what the old broadcast engineers figured out decades ago for voice intelligibility over narrow bandwidth.

on the ALC thing — you want to see it moving but not pinned. if your ALC is sitting at max the whole time youre talking, your mic gain is too hot and youre probably compressing or clipping somewhere in the chain. on the 7300 specifically i run mic gain around 50-55% and let the ALC bounce around in the lower portion of its range on peaks. some guys swear by the built in speech processor too but i find it makes things sound harsh if you push it too far, subtle is better.

the PR-40 is a large diaphragm dynamic and its kind of voiced for broadcast so it does lean bassy by nature, which probably explains your reports. icom's menu EQ can fix a lot of it but you might want to experiment with mic placement too, getting further off axis can reduce that proximity effect buildup on the low end.

yeah the ALC thing confused me too when i started on SSB. what helped me was just watching it while talking into a dummy load and adjusting mic gain until it was dancing around maybe the first third of the meter on normal speech and only hitting higher on loud peaks. once i stopped chasing full deflection all the time my audio reports got way better.

one thing nobody mentioned to me for a long time — room acoustics matter more than you'd think. i was getting this weird hollow echo in my audio and it turned out my shack has a really reflective wall behind me and the mic was picking it up. threw a moving blanket over my bookshelf behind me and it cleaned up noticeably. probably sounds obvious but it took me forever to figure out