Mundorf Silver Gold Hook up wire

I tried Mundorf Silver/Gold hookup wire in a preamp and found it to be too lean in the bass; however, this was the 24g version and you would probably be using 18g or 15.5g for the internal speaker wiring.  The thicker wire might very well sound better balanced.  At the price of these thicker Mundorfs ($15.75 and 27.00 per foot respectively according to PCX), I would recommend trying Audio Note Lexus instead.  This is a copper Litz cable that I have found to work exceedingly well as internal speaker wiring.  It's available from Hifi Collective in the UK which has a good website for placing orders and fast shipping.  You do need to use a solder pot for the proper tinning of the ends of the enameled wires.  

I used a double run of the 18 gauge in my amp and really loved the sound. Nice warmth and richness along with the details. 

I used the 24g to make a usb cable that also turned out fantastic. Sounded better than my favorite Curious usb cable. Wonderful rich tone.  

It will get costly to use the 18 gauge, but I think salectric is correct and the heavier gauge will give improved tone and weight. 

I have not tried the Audio Note Lexus, but am now looking at it. 

I appreciate the feedback gentleman.