Having recently upgraded my Marantz cd player and amp to a rather very good Roksan [MK III} coupling I'm beginning to wonder that although it sounds awesone through my old Tannoy M15 speakers which were quite expensive 20 years ago; has speaker technology changed that much that it would be worth lashing out more money on a pair of mid-range speakers or would the difference be minimal. Ive been wrestling with this problem for a while now. I would be gratefull for any advice at all! Thanks.