Quote:

My room is irrelevant. ...



When you are mixing using monitors your room is very much relevant. ... and mixing using headphones has all the problems that have been discussed numerous times before (I mix using headphones -- ha, ha -- and monitors).

Quote:

...foam lined enclosure that is completely anechoic ...



Foam usually absorbs mid and high frequencies, so you probably have real bass issues in recording your vocals.

The reason you have too much bass and then not enough bass is most likely due to your room and your monitors in your room (and the headphones are not solving that issue for you).

Just my relatively "acoustic treatment" novice opinion here.


Now at bandcamp: Crows Say Vee-Eh @ bandcamp or soundcloud: Kevin @ soundcloud