so i finally pulled the trigger on doing the TX audio mod that's been floating around on qrz and a few other places — basically adjusting the TX bandwidth by tweaking a couple of the internal settings and also swapping out the stock electret element in my desk mic for a dynamic capsule i had lying around from an old shure. the idea was to get flatter, more broadcast-style audio and cut some of the mid-range honk that the 7300 has stock.

results are... mixed i guess. on-air reports are better in the sense that people say i sound less nasal, which was the goal. but now im getting complaints that im too bassy on SSB and my ALC is behaving weirdly, like it's hitting harder than before on peaks even though my drive level hasn't changed. i think the impedance mismatch between the new capsule and the mic input might be doing something funky. either that or i messed with the TX equalizer settings in the menu and forgot to document what i changed before i started which was really dumb of me.

anyone done similar mods on the 7300 or even the 7100 for that matter? curious if there's a sweet spot for the internal TX EQ settings or if i should just add an external in-line EQ between the mic and the radio. also not sure if the ALC thing is related or totally seperate issue.

yeah the ALC behavior change is almost certainly the capsule impedance thing. the 7300 mic input is expecting somewhere around 600 ohms for the electret and if you threw a low-impedance dynamic in there without a proper impedance matching transformer or preamp stage you're going to get weird gain staging. the radio's input amp is probably working harder than it was designed to which would explain the ALC going nuts on transients.

i did something similar on my 7100 about two years ago, ended up putting a little inline preamp/impedance matcher between the mic and the radio and it sorted everything out. there's a schematic floating around on the icom reflector that someone designed specifically for this. before you go messing with more internal settings i'd try fixing the impedance problem first because right now you're basically trying to EQ around a fundamental mismatch and that never ends well. document your menu settings this time lol

not to go off on a tangent but this is why i just run everything through a behringer mixer before it hits the radio. yeah its a bit of extra desk clutter but you get way more control over the audio chain without ever touching the inside of the rig. my audio reports went from mediocre to genuinely good just by having real EQ and compression before the mic input. zero voiding of warranty too which matters to me since my 7300 is still under extended coverage.

the internal TX EQ on the 7300 is honestly pretty limited once you start pushing it, only so much you can do with those few bands. if you do want to keep going the internal route though i'd reset to defaults first and start fresh rather than trying to figure out what changed