u mean i need a cable which have coaxial in [plug in speakers] to sd SPDIF Coaxial output [plug in Tata Sky box] . if yes then its a true 5.1 ? and plz any link of cable , thankx alwaysajuravi007 said:For optical in HTS need not buy converter but you have to buy optical out and in cable....which would cost around 300 - 400....