How important are speaker cables to the sound emanating from the speakers?

IMO if your system isn't capable of resolving the tiniest differences it is unlikely you will hear any difference in cables below a certain price point although copper & silver/silver over copper comparisons may yield results.Of all the cables I have tried(several Audioquest mid level,Nordost entry level,Signal & Marrow)The Zero Crystal Copper Zen Acoustics got my $.

Freediver, I will politely disagree with your conclusion regarding the nature of components and benefit of cables. I have built many systems in the $2-5K range, and every one has been as sensitive to cable changes as the "big boy" rigs. No, you cannot expect precisely the same result as with better systems, but the cables do effect significantly - by that I mean easily heard and repeatable changes - even modest systems. 

Two incidents to consider. The first system I tried to test cabling on was what would be a solid MidFi rig. It was nowhere in sight performance wise to what I can build now. My first cable test was some extremely thick cables purchased from a home improvement store, with such gauge that when I twisted all the individual conductors together I could barely fit them into the posts of the amp! Instantly I heard the difference between it and lamp cord, and I knew at that moment the wires are critical. That was a revelation which occurred on a system with compromised performance and with very average cable, but with large AWG.

My second "I don't believe it," moment occurred a few years ago when I had a boom box which took a C7 plug. I had just upgraded my power cord for Sonos to an aftermarket one, an Audioquest. I wondered if the difference in a power cord to a boom box could be heard. I knew enough not to discount the possibility altogether. Yup, it did make the boom box sound different, another evidence that cables matter no matter what the electronics.  :) 

I'm with Doug - I had the same experience with a $350 mini system where upgraded power and speaker cables made significant improvements in SQ. And the cable used was not that expensive.

Regards

As with most things in audio the effect of speaker cables will be very system dependent.  Case in point, my experience has been the opposite of 69pete's in that in my system interconnects produce very noticeable differences whereas with speaker cables the differences are much more subtle.  But to one of Al's fine points, my speakers are an easy load and impedance stays relatively high across the frequency spectrum.  I use Acoustic Zen Satori shotgun biwire and find them to be an excellent all-around cable, but obviously YMMV.  

You opened up a Pandora's box of opinions here ... so let me stoke it a little further. Go ahead and Google [ speaker cable blind listening tests ].

Or better yet, get a friend and some cables and try it yourself.

Those who don't like what they read will say that blind listening doesn't work. That you need to live with the component to learn all of its true nuances. Funny how we enjoy the only products on earth where blind testing isn't useful!! Yes it's true for example that a loudspeaker may reveal itself to have certain spikes or dips or anomalies only after listening to many different performances over time. But I immediately know if a speaker that I haven't heard before is great or not after 30 seconds of listening, and then further listening will reveal to me all of its strengths or weaknesses.

I myself have a handful of musical references that I have been using for 20+ years, and so when I listen to a new piece of gear using these references I know almost everything that I need to know immediately. But more often than not, I do know everything I need to know and further listening proves no help. And I work in an industry that requires me to do a lot of blind audio testing on a daily basis.

So of course blind listening is useful in audio, that is self-evident, but it does sometimes require further time and repeated listening.

That being said, go ahead ...  Google speaker cable blind listening tests ...

Happy arguing!