InstallGear 16 Gauge Speaker Wire OFC Oxygen-Free Copper, 100-feet

Rewired my vehicle with this. Good thick wire, flexible jacket, easy to work with. Nice stuff, looks and feels like good quality.

Used this to connect my speakers together, and it works PERFECTLY. I love it. Used about 13ft and the sound didn't even diminish in quality at all.

Cable de muy buena calidad

Maybe you can get better, but you won't need better wire unless you're planning on putting together a competition-worthy aftermarket system. This wire is handling 4x door speakers and 2x amps powering those speakers plus two shallow mount subwoofers. I don't think there is any loss in performance - not that I could tell because everything gets more than loud enough so I never run my system beyond ~66% volume anyways. 16 gauge is plenty for both subs and smaller speakers as long as you're not running the lines really long (say, 25' or more). If you need to run really high powered systems (well over 100W RMS per channel) or have a long cable run to deal with then maybe step up to 14 gauge, but this is plenty good for my system that totals ~900W RMS at the moment (I'm making some swaps that will actually drive the total system power right up to 1000W RMS and expect there to be no issues using this wire). I have no complaints here - get this wire if you're OK with the price (I think it is competitively priced). Don't cheap out and get aluminum braided/composite stuff. That's no good at longer runs and can't handle higher power needs.

Good product.