Benny Z,
nice, got mr-2 with 8" extension, and one beckett, some have notice better performance with one beckett rather than two becketts with the pcx-55,
I would try it both ways and decide for yourself,
In my opinion the pcx-55 is only good for one beckett head, two will be too much and performance will decrease too much, you need something a long the lines of a ps200 (panworld) or BL55 (blueline), iwaki 70, ect for two becketts,
anyway good luck,
sam