I have this exact same issue. I didn’t have it originally prior to updating the firmware so that might have been the culprit. But basically I had the exact same sequence of problems and eventually narrowed it down to being a bad mic (or so I thought) because like the OP, I used an old mic I had with a pioneer elite receiver and that seemed to work fine but obviously isn’t calibrated like the audyssey mic for the denon
so long story short I contacted denon and they sent me a new mic, unfortunately still having the same issue with the new mic
so I’m not sure what to do from here - OP please let me know if you end up figuring out how to resolve
if I could figure out how to reset the firmware to original that might be a good test
It seems from my enquiries that Denon/Marantz now have a slew of bad mics out there.
Basically those mics are the cheapest of junk.
I always thought that the mics were dynamic, as they have no battery and the the cable is two pair. Since I had trouble with my mic, I find they are in fact condenser mics. So they are powered though the signal cable in a two wire system. This is a totally appalling and unacceptable design. For proper and reliable phantom mic powering you need two cables carrying the signal AND a screen with a three pin connector not two pin as are on these perfectly horrid mics.
So the pro way, and not the mickey mouse way to do this, is to have the +ve voltage on BOTH of the the signal cables and the -ve on the screen. Both legs of the signal should be at identical voltage above ground. Any other way is NOT acceptable and fraught with troublesome issues.
If it works, these mics are good enough for speaker level and distance, but absolutely nothing else. Since my issues I have have learned more as to why Audyssey is a totally unacceptable system, and certainly not to be used for any critical equalization. It is a lousy misbegotten system from the ground up, and not anywhere near professional standards that those of us with advanced sophisticated systems require.
