I have a Hsu Research STF-2 which has worked fine for me with the Vandersteen 2ci. I have tune the sub where is seamlessly with the 2ci to a point where is like a house curve response. This usually a boost in the bass region and a downward slope to the high end region where usually around -3 to -6 db below reference. So to answer your question, you would need to do it once after you figure out the right placement. Find a well recorded music with a full spectrum response.