Recently upgraded to General and just got my first HF rig (IC-7300). I've been getting reports that my audio sounds muffled and hard to copy on 20m SSB. I'm using the stock mic with default settings. What are the key audio adjustments I should focus on first? I see lots of menu options for TX EQ, compression, bandwidth settings but don't want to make things worse. Any guidance for a newcomer to HF phone operation would be appreciated.

Start with transmit bandwidth - set it to 400-2600 Hz for DX work, and roll off bass below 300Hz while keeping the important speech frequencies between 300-1500Hz. That alone will make a huge difference in clarity.

Your average power should only show about 30W while speaking with proper mic gain - if you're trying to see 100W on average reading, you're overdriving everything. Set high pass to 100Hz to avoid muddy bass that wastes power and makes you harder to understand.

On the 7300, go to Menu > Set > Tone Control > TX > SSB. Set Bass to -2 for starters and Treble to +5. When using compression, aim for about 5 dB on voice peaks. Listen to yourself on monitor and adjust from there.