so ive been going back and forth on this for a while now and figured id ask here because theres a lot of conflicting advice out there, especially on youtube where everyone seems to have a different opinion on what makes SSB audio sound good on HF.

my current setup is a 7300 with a Heil PR-40 through a cheap interface i built myself, running into about 50 ohms. on my end it sounds great in the headphones but ive had a couple guys tell me my audio is a little bassy and one guy said i sounded slightly processed, which i definitely dont want. im running the TX bandwidth at like 2.4 kHz which i thought was pretty standard. compression is set to maybe 3-4 on the radio's built in thing.

so my actual question is - what settings do people actually mess with that make a real audible difference to the other station? like is mic gain the main thing, or is the TX filter cutoff worth playing with, or is this one of those things where 90% of it just comes down to the mic and the room you're in. ive read so much about this that i feel like ive gone around in circles and dont know what to actually trust anymore.

the bassy thing is almost certainly your mic placement or the PR-40's proximity effect - that mic has a LOT of low end when you're close to it. try rolling off below 150 or even 200Hz on the TX filter and see if that clears it up. on the 7300 you can set the low cut in the TX bandwidth screen pretty easily. the difference is actually huge and most people never touch it because they assume 100Hz to 2.8k is just the right setting out of the box.

compression is a whole other thing. 3-4 might be fine or it might be killing you depending on how your mic gain is set going in. the general rule i follow is set your mic gain so you're just hitting ALC on voice peaks with zero compression, then bring compression in after that. if you have to crank the mic gain to get any ALC movement at all, something else is wrong upstream. the 7300's built in compressor isnt bad but it responds differently to different input levels so the order of operations matters a lot. honestly the single biggest thing after mic placement is probably just monitoring yourself on a second receiver or having someone you trust give you honest audio reports.

yeah what he said about the low end. i had the same issue with a different mic and just cutting that low shelf made people say my audio suddenly sounded cleaner even though it felt thinner to me on my end. you kind of have to trust what the other guys are hearing not what you hear in your cans.

one thing i'll add - USB vs the built in sound card on the 7300 matters way less than people argue about online. the room you're in honestly matters more. i set up in a spare bedroom with a bunch of bookshelves and blankets on one wall and it made a noticeable difference vs operating at my desk in a hard-walled office. maybe not the sexy answer but its true.