With much... patience! It has to stay in place just by its own elasticity. You have to cut two straight pieces of tubing slightly longer than the circumference, and then fit them in place, one below the diaphragm, another above. The join of the outer gasket is usually placed behind the needlebar in order to conceal it (but if you do a good work it would be almost invisible anyway), the join of the inner gasket is usually placed at the opposite side, so in case there is a small air leak, the air will have to take the long way to escape.gokenyon wrote:How do you fix it in place?
Refer to any soundbox rebuild tutorial, it will show this with pictures. This one shows the steps on an Exhibition soundbox which has a design very similar to yours.