The cones on my 4 year old Sony XS-MP1621 speakers seem to be falling apart. Surprised as they are mounted on the underside of my hardtop and are never directly exposed to water. Looking for replacement recommendations. I don't have an amp and I don't attempt to listen to the stereo while underway. Just some easy low volume listening to classic rock while waiting for the fish to bite or motoring around the ICW. Current speakers are 6.5" diameter in a 5" cutout, so I would hope to find a similar size for easy replacement. Looking for something in the $100-$150 per pair.