Best furniture to act as bass trap

cloth might 'trap' high freq.s a bit better than leather due to the surface roughness

I will bet on no difference for bass, AND double down on neither having much if any effect on bass

I think the above poster is thinking of a Tuned Membrane Bass Trap.  This is, of course, tuned.  The couch is not.

Why do you think here's some element of more efficient bass absorption when you place a flexible reflective material in front of a highly absorptive material??

I agree with shadorne

measure first of course

DSP may be in your future...