Thankyou for your advice stein .It may be that the 8/9k Fralins are great for a Les Paul-335 ect but are too hot for the body chambers of an archtop where there is much more air born resonance.There is evidence that light potting can help. Too much potting can isolate the pups and damage the acoustic relationship between body and pickup.I think the answer is to fit lower output pups or ones designed specifically for an archtop. -regards -Neil