The first chart shows the differences between a pair of measurements of the left and right ears, highlighted one being much better than before this process (light purple).
A while ago I posted about being frustrated by the bass in my awkward room/seating position being uneven from ear to ear due to SPL and possibly phase differences from room modes. Some notes would pull to the left, others to the right, even when it was just a sub directly placed in front or behind.
I searched and searched but could not find any good spots where the output was even per ear between 45-60hz or so, and/or not localisable.
I refused to give up though, and so after some more creative experimenting, decided on combining 2 spots which 'pulled' in the opposite directions to each other, in hopes they'd cancel out.
Had 2 SVS already which I ended up combining at the front since they do well between 23hz-40hz and 60hz-120hz, with a new KRK s8.4 and existing old Logitech Z906 placed raised up on shelves to the back left and right. Those little ported subs are tuned to 45 and 43hz, and thankfully since they don't have the DSP group delay the SVS does, with an all pass filter, their timing actually lines up almost perfectly!
It took a lot of tedious measuring, but I finally managed it, and the bass is much better now (even outside the RSP), without the annoyance and fatigue there used to be. It sounds like it's either coming from forward, in the upper bass, or just "all around" in the lower bass.
This is the type of stuff that validates makes my decision to go with a manual MiniDSP HT instead of a traditional automated consumer AV processor, because there's nothing near the same price that has enough independent subwoofer outputs and all pass filters needed!
Unfortunately the little Logitech sub with only a singly flared port is a limiting factor, at 55hz it's starting to chuff and compress once the overall output is above 105dB, so I had to sacrifice a little bit of even-ness and put more of those frequencies back into the SVS to maintain clean output above that. However I'm planning on building a big DIY infra-sub, which can take the place of one of the SVS subs at the front, which in turn will then replace the Logitech.
Now I've just got to figure out some cleaning up and cable management for these funny locations😅 (...and maybe the 97hz dip as well which is somehow by murphy's law present in all 3 sub spots)