sold a pair of tannoy's dual concentrics to a cutomer who moved over to the uk to live, this was on a saturday, monday first thing monday he came back in a rage complained that the speakers were broken, so i took the covers of and tried hard to comunicate as to why there was 5 holes round the voice cone, he then "ater a while" explained thet he used them at his party and "as natural" the cones were moving to and fro, so he tried to stop them moving by holding them with his fingers, i give up..!!!!!!!??? nando