so ive been on HF for a few years now and i keep getting mixed reports on my audio. some guys say i sound great, others say im a bit muffled or that theres some kind of low frequency rumble. im running an IC-7300 into a Heil PR-40 with the heil adapter and i thought that combo was supposed to be pretty foolproof but apparently not.

ive been reading about things like the bass rolloff in the radio's TX equalizer and whether you should be boosting mids or cutting lows but honestly the menu system on the 7300 is kind of a rabbit hole. i set the TX bandwidth to around 2.4 kHz which i thought was standard but maybe thats part of the problem.

also wondering about mic gain vs compression. right now i have the compression on fairly light, like 2-3 on the meter, because i heard over-compressed audio sounds terrible on SSB. is that actually the right approach or am i overthinking this. any tips from people who have actually dialed this in would be great, especially if youre using similar gear

the rumble is almost certainly low frequency pickup — either from your desk, HVAC, whatever. the PR-40 is a dynamic so it's not as sensitive to that as a condenser would be but it still picks stuff up if the gain is cranked. first thing id do is go into the 7300 TX equalizer and roll off everything below about 150-200 Hz, like a pretty steep cut. you dont need any of that on SSB anyway, the filters in the receiver on the other end are going to chop it off and all it does is eat up your headroom and make the audio sound muddy.

on the compression thing, yeah 2-3 is pretty conservative but that's not necessarily wrong. the issue is the 7300's built in compressor isnt the greatest in the world. some guys run it a bit higher like 5-6 and then back off the mic gain slightly to compensate. the idea is you want the peaks controlled without squashing everything flat. honestly the best thing you can do is get on with a buddy on a nearby frequency and have them give you real time feedback while you tweak. way faster than guessing.

yeah the TX EQ on that radio took me forever to figure out. one thing i noticed that helped my audio a lot was actually the mic position, like how close i was to the PR-40. i was talking kind of off axis because i read that reduces plosives but i think i was too far off and it was making me sound thin and distant. moved back to talking more directly at it from maybe 4-5 inches and suddenly reports got way better. not saying thats your problem but it's worth checking before you go too deep into the menu settings