highend64 I apologize for not being more helpful. While you moved the HSU slightly and it measured differently is not how to position a subwoofer.
The most effortless, quickest and practical way to find your rooms standing wave bass modes must be done with the -2dB HSU placed at your listening position because its the location you're actually trying to improve the subwoofers performance within the room. Think of it as a sort of reverse engineering.
Connect one or two long inexpensive RCA interconnect cables (from Blue Jeans or Monoprice cables) to the subwoofer.
Purchase or download a low frequency cadence tones that can be constantly repeated.
As the tones are being played slowly walk or crawl around your rooms boundaries listening for the strongest best sounding bass. Make a map of these locations within the room as you'll only have to do this once.
With the HSU positioned now in the most convenient mode location readjust the subs parameters while listening from the listening position first with the bass tones then with music, by ear. There is no right or wrong as to what you feel sounds best.
This method does not work with -6dB rated speakers since they simply do not play play low or loud enough to excite the rooms modes so there's nothing to integrate.
Room size has nothing to do with the delicate extra low bass. You can hear it in many headphones. So why give up on it with a -6dB sub bass speaker?
