Finolex electrical wire 4.0 sq mm dual core. works out closer to 11 gauge. i previously had doubled up 16 gauge acoustic research speaker cable. the reason i changed it was that it was looking shabby. from a change in SQ, i cant really say for sure, but i did feel some improvement in the tightness of the bass and also slightly brighter in the mids and highs. again, i wont say that it has moved from neutral to brighter, perhaps more towards neutral. to reiterate, the SQ difference is very minimal, if at all.
cost was about 60 rupees per meter. 99.97 pure copper. really thick wire - found it difficult to fit into the speakers. you also get 2.5 sq mm dual core wire which is closer to 13 gauge