Weight reduction of 90% sounds great ... but like most press-release statistics mean not a lot .... saving 90% of the weight of a pair of modern car speakers is probably less than having a pee before going for a drive ... sounds a bit like a solution looking for a problem
I have no idea how Sennheiser get their 90% reduction, but in the world of guitar cabinets the move to neodymium magnets is helping to get weights down to manageable levels, which helps when lugging kit around for gigs and such. My living room amp is a Victory V40 Combo and although it sounds absolutely fantastic, it weighs 50lbs so you really don't want to be carrying it any distance. I'm sure the Sennheisers wouldn't weigh that much anyway, but a speaker can be a fairly chunky bit of kit.
