Folded Horn speakers work like a trumpet in that the sound comes out of an expanding tube/box. To make it fit into small spaces the tube can be folded. As long as the fold continues to get wider then it has a chance of working.
The rubber surround had split in a number of places. So I repaired the splits by using a rubber/latex glue called Copydex together with a very thin but strong rubberised cloth cut from a cheap glasses drawstring case/bag.
This is a view of the gluing. Several layers were added, but not too much as to restrict the speaker moving. Its not very pretty but it works, it takes 110 watts RMS with ease.