Actually, I think that this whole thing started as a misunderstanding.
The speakers were initially reviewed without feet, leaving four small holes in the cabinet bottom and the tester said that he saw an anomoly in the impedience curve. I don’t know that he originally shared his curve, but what it was was a tiny lump in a portion of the curve where it really doesn’t even matter.
He reported the anomoly and the mfg suggested that he needed to put the feet on to get rid of the shift in the curve.
BUT, I think that they were talking about two completely different thngs!
The feet were installed and the reviewer did infact notice a shift in the impedience curve, just as the mfg said there should be. But, this was not the same shift of which the reviewer was commenting on, and infact, he never even noted this shift due to the lack of feet. Also, the reviewer and mfg never did agree on what frequency the shift was occuring at.
The reviewer attributed this miniscule bump to an enclosure resonance to which the mfg took offence.
The reviewer then retested the speakers this time also turning them upside down and noted that when turned over, the miniscule bump was now gone, and this is evidence of the top panel being resonant because the weight of the speaker dampened the panel resonance.
But when I look at his data, even upside down, I still see the bump, though it is slightly flatter and broader.
If the reviewer really thought it was a cabinet resonance on the top panel, he should have laid a towel on it and put a cinder block on top of that to dampen this resonance and checked again. For all we know, an interior piece of insulation hangs in a different orientation in the upside down test causing this slight difference.
