It's called a subsonic filter (as I'm sure you know), but I certainly would not do this with passive components. You'd need something like a 50 mh inductor just to do a passive 1st order high pass at 25 Hz. That *will* degrade sound big time.

Every component in the signal path degrades the quality. Subsonic filters should be done activally only.

I included a chart of power input vs frequency in typical musical material.