I use the Kenwood TS870, and it has numerous settings for the audio. I find that using 2.8 Khz or 3.0 Khz on a dx contact has worked rather well, especially since I just operate without an amplifier. I have received many unasked for compliments on the audio of the transmission. I have tried various settings such as 2.4 KHz or 2.5 Khz , the results vary depending on who is using what to hear me. That ALC level has a lot to do with having a decent signal versus a distorted signal. Occasionally when on 80 meters I can hear a group of operators just above the Extra portion around 3803 that splatter the hell out of every radio I have. They must be using gear set to 5 or 10 kHz like Radio Habana Cuba and their crappy modulation. However , advising them of the interference is about useless since their excuse is your radio is junk. So I just avoid the morons and try to prevent myself from representing an oxymoron.