Are there any acoustic treatments in the room? Was the room designed with acoustics in mind? I'm thinking not, it was designed for sleeping in.

I can't answer if moving to a room with vaulted ceilings would help because you specify nothing at all, or post any examples for help with equalisation.

In reality, I don't think anyone could give a really meaningful answer. Accept maybe the vaulted ceilings will help.

Can you expand with some room dimensions and maybe an example?

Small rooms (technically, anything smaller than 3000 cu ft) generally always suffer from excessive low frequency build up.

Vaulted ceilings may, or may not, help your issue. Again, it is more related to the size, volume and L:W:H ratio of the room as to modal and nodal issues. Those numbers, in turn relate to the overall need for acoustic treatment; absorbtion and diffusion.

Yes, you can possibly eq the problem away, but with ANY eq solution, you will introduce phase problems. Sometimes the phase issues are minimal, sometimes they are quite significant.

You can also combat LF issues by using a microphone's LF roll off switch, and optionally, the LF roll off on your console or DAW channel strip.

Generally, it's best to reduce the low frequency build up by installing broadband bass trapping in the corners of the room... wall:wall and ceiling:wall.

Could be mic placement, too. Do you hear the bass build-up when you're not recording? If you don't, try backing up off of the microphone: even if it does mean picking up more room sound, you'll counter proximity effect (especially with the HPF on) and you'll probably pick up the entire sound of the instrument rather than just the soundhole's emissions (dirty) or summat.

I often record in a room (my apartment bedroom) with ceilings just as low and without treatment and my recordings turn out swell.

"I moved my entire studio into a bedroom that has really low wood ceilings (7-8 feet)"

Which one is it?

Carpet on the floor and hard surfaces all around? Square room?