I did a quick test on each of the speakers in my 1960 A Vintage Quad box. I tried to get the mic in the same position on each speaker (right in the middle straight at the dust cap) There was a big difference between the four speakers. There is about seven seconds of each speaker at the start here. I chose the best two to record and as you see I couldn't help myself again. Before I finished doing anything properly I was off recording, playing around as usual.