AudioQuest FLX/DB 14/4 In-wall Speaker Cable
This stuff is great! But please use it only selectively. I believe this is rated for direct burial, and that's what it's great for-- I've used it for that in the past. But if you try to use it internally in a rack for example (like I just did) or send it through a wall you will find it unnecessarily thick and hard to work. Another pro tip: again, because it is direct burial the insulation is thick, but deceptively so. Strip it too aggressively and you will put a nice little notch in one or more of the conductors which is just about the perfect way to short the whole thing. I found that simply scoring the outside of the insulation with a basic pair of scissors, and then bending it until it came off was the best way to ensure no conductors got notched from more "enthusiastic" stripping. Docking one star for all of the above. Despite this, of course and generally, four conductor cable is EXTREMELY convenient, especially for multiroom audio, and will yield the cleanest possible install.