Posted by John Vogt on November 30, 2002 at 08:03:17:
In Reply to: Re: Re: Membrane Heat-Treatment Instructions posted by Roy on November 29, 2002 at 09:45:13:
Roy---
That's right, I treated through the spandex. With the right heat gun you won't damage the grille. I've found the cores to be very flexible and w/ the frames of the U1's, my frames at least, not exactly lining up w/ the sides of the cores there is some amount of twisting causing the membrane tension to change.
I would check over the membranes of your speakers to see if any wrinkles have been introduced after reassembly. If not you should be in good shape.
BTW, thanks for posting the heat treatment instructions. While measuring mine I found the primary resonance to be 24hz but noted in Rogers directions that the membrane should be 30hz. I emailed him and he confirmed this, recommended I heat treat them again to raise the resonant point.
I'm going to do this but will wait until after the holidays so if I screw it up I won't be w/o music.;)
I hope this will tighten the membrane enough so it will be more resistant to hitting the stator during high level drum passages.