If you are hearing a 'room' effect (often a certain boxy or reflected sound), then room treatments may help.
Even then, experiment first.
While recording my daughter and a friend one night in her room I picked up on this.
I moved the mic from the room it was in and put it in the hallway outside instead (which opens to a stairwell).

The issue was instantly resolved .. plus I discovered that if I open the other doors beside where the mic sat I got an even clearer signal. These were likely direct side reflections.

Anyway, if this is the case I suggest experimenting a little first, as I found a nice spot for the mic just 8 feet away. And less effort. I've recorded many other tracks there since discovering this.

/The wife needs to be notified in some instances, as answering her phone could ruin a take!
Otherwise if it is actually just 'crispness', a compressor and EQ may indeed help quite a bit.

I do not work here, but the benefits are still awesome
Make your sound your own!