I've noticed quite a few operators on 40m lately with overdriven audio that sounds absolutely terrible. The mistake many make is trying to see 100W output on their average-reading power meter by maxing mic gain, which results in horrible sounding audio and dirty signals that interfere with adjacent frequencies. With proper mic gain configuration, SSB should only show about 30W on an average power meter while speaking. Your ALC should barely flicker on voice peaks. Use a dummy load and second receiver to dial in proper settings - you'll be amazed at how much better you sound with conservative gain levels.

Great advice! My TS-590 mic gain is set at only 5% and still produces full 100W PEP with average around 35% where it should be. Too many hams think louder is better, but clean audio gets through much better than processed mush.

This explains why I can't seem to break pileups despite running 100 watts. I've been running my FT-991A with mic gain at 75% thinking more was better. Time to back it down and use the dummy load setup you described.

The FT-991 gets dirty fast with heavy ALC, while the IC-7300 handles it much better. Each radio has different IMD characteristics. Monitor yourself on a second receiver - there's a sweet spot where increasing gain doesn't make you any louder, just dirtier.