I am using a 3rd order filter specifying a 39uF midrange circuit cap. I can parallel 2% tolerance caps to a value of 38.2uF. Will the deviation from specified value likely be audible?
Unless the circuit is critically tuned, that small of a deviation will not be audible.
That said, 38-39uF may not actually be the value needed for an acoustical 3rd order filter, having some other values to experiment with is always a good idea.
Well, I guess that would be a worst case of 37.44uF, which is a 4% difference from the specified value. More likely, something like 2.1%. I'm gonna say no.