John. Ear height sitting is pretty close to the 4' level. Certainly closer than when standing. I have a deep narrow null at 71ish Hz. at ear height in my room, but it is not that audible.

I am wondering if there is a combination of things going on to create a wider null. Reflections from the front/back of the room maybe??

Fred

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Blujays1: Spending Fred's money one bottle at a time, no two... Oh crap!