So I posted this over at AVS as well, and I got two replies from non Axiom sub owners experiencing the same thing, so I am pretty sure it is not the DSP chip. This is just a guess on my part, but I wonder if there are different things at play at the different peaks and nulls, and when I turn the volume up or down, these differences are affected differently. I also wonder if I could possibly use the word different any more times in one sentence. Any other thoughts would be great.

BTW, I am really sorry Dennis for jumping in on your thread like this. I am realizing now I should have started a new thread for this. Hopefully it is not a big deal