I agree with all of the above. Close-talking a mic will allow for the best signal/noise ratio from an audio point of view. It eliminates the background npise etc. 99.99% of the time an amplified mic is not required to fully modulate a radio and extra gain is almost never NEEDED if you talk close to the mic.
The best way to figure out mic level and distance is to listen to yourself through a monitor radio. I use a Cobra 148 with no antenna and headphones to check out radios with different mics. I also use it to check my station when I first power up for the day. Makes it so much easier than trying to get a radio check. If you have a second radio, this is the way to go.
If you could plug in some headphones, it would be perfect. Usually talking close to the mic will increase the bass response. This works great for a D104. I like to run a hot mic, so I can dial it into the sweet spot while listening to myself. I adjust it for "Loud without the Crunch". Also, I find that a lot of times the perfect settings for AM and SSB are different. SSB can often take more audio, but that level would be too much for AM. I just do a quick check when switching between modes, and then off I go into DX land.I use a HH uniden without the antenna too check how my radio sounds. I get feedback sometimes but turn down the volume on the HH. I mean an on air would be better but not that easy sometimes.
Plug an old set of headphones into the speaker jack on the monitor radio, makes it even easier to stay away from crunchy audio. I have tried it without the headphones and it kind of works ok, try some headphones and see what you think.I have a second antenna I set up just to monitor my transmit. Then I discovered that the 39inch Workman Saturn B100 makes a great scanner receiver only antenna for local counties VHF high band 155mhz dispatch channels. Its now my scanner antenna for police, EMS, fire. I took the radio off the mount that used to be hooked to it. I should just put is back as a monitor radio with no coax. I had an old JcPenney 6218 was hooked to it that I normally left on Channel 19 to monitor all day. The fancy simulated wood grain coating on the case covers caught my attention when I pick up the 6218. It was mounted far enough away from the other radios that I should not have a problem with squeal.
If you could plug in some headphones, it would be perfect. Usually talking close to the mic will increase the bass response. This works great for a D104. I like to run a hot mic, so I can dial it into the sweet spot while listening to myself. I adjust it for "Loud without the Crunch". Also, I find that a lot of times the perfect settings for AM and SSB are different. SSB can often take more audio, but that level would be too much for AM. I just do a quick check when switching between modes, and then off I go into DX land.