Tom,
I used the Belden 5000 series Cable, 10-guage, from Blue Jeans cables:
https://www.bluejeanscable.com/store/speaker/index.htmThough I've been a high-end audio nut much of my life, I'm not big on spending money for high end boutique cables, which makes me a bit unusual I guess in forums like these. (Even though through my friends and contacts I have access to, and have listened to, some of the the most expensive cables in the world from Nordost and many others).
I like Blue Jeans cable because they are a no b.s. company, you can find measurement specs for the cable, etc.
I located my source equipment down the hall from my listening room so I had to run speaker cables under the floor to my speakers - about a 25 foot run or so. The Blue-Jeans cables have excellent specs for long runs and I went with 10-guage, which is probably over-kill. But what the heck.
As I said: I've heard some speakers I own with with these cables, and with the highest end Nordost, and...well...even for a super picky listener like me I'm happy where I spent my money :-)
As I've written about earlier in the thread I have to sell my 3.7s because they are just big enough to impede traffic flow in and out of my listening room. Despite auditioning the newest-thing speakers out there, the 3.7s have been sooooo hard to replace because they just seem to effortlessly "do it all."