U r recording in a very small space, covered with materials which absorb the same fq spectrum all over.

The sound is bound 2 b colored.

However I m not sure what U mean by "flange".

Flange IS delay driven, however the delay needs 2 vary 4 the flange 2 occur.

U could b hearing phase cancelations or a short nasty slap reflection, colored reverb or all 2gether.

Try this:
While singing and recording, move the mic around, and notice the change in tone.

Then tell us what happened, or better still upload a clip somewhere.

Peace,

Zooot