Batboard

Would I be better off disabling all the pre-emphasis and de-emphasis on a CDM UHF when I am on the ham bands as some people are complaining about the audio, I have changed the mics, trying an older Hmn1035a, to an Hmn1035c which sounded better to an hmn4072a which sounded best of all three. my mic settings are the default and would really like to use the 1035a as I like the feel of it best.
Thanks for any information in advance.

Short answer - no.

You should find a way to listen to your mobile to determine in what way your audio sounds "bad". It could always be their receiver too. Or their ears. Audio quality is a very subjective thing.

Is the default mic level settings the best or should they be lowered a bit? What settings is everone using?

Never heard complaints on CDM's audio. They are sound great with all mics!

Leave De-emphasis and Pre-emphasis turned on. Turn aff compression and expansion (if you communicate with hams or your radio network do not use compression/expansion).

And when you communicate with hams, check channel spacing - most of ham rigs have only 25 kHz IF filter (but have no very narrow 12.5 kHz IF filter) and you always will get reports about low voice level. And if you set up for 12.5 kHz spacing, you can hear some clicks/rustling (especially on loud phrases anb pops) when you receive transmissions from ham rigs. And some radios, like is Alinco, have very wide deviation (up to 25-30 kHz).

Also turn off APF (Audios Processing Filter). It distort sound (but effects on RX only).