Why do you think Bi-Wiring improves the sound ?

The terminals were fitted for one reason and one reason only: to give the user choice. Have I ever used them at exhibitions? No. Have I ever used them for critical listening? No. Have I ever used them during the design of the speaker? No. When we were offering the biwire terminals, right at the end of the design process (which has all been with single wire) I took a saw to the prototype PCB, cut in in half to isolate the bass and tweeter sections and then made a pretty PCB layout based on that. Did I listen to the biwired crossover before authorising production? No. Do I believe that even 0.00000001% of enhanced performance can be gained? No. 

This sure sounds like hard science. Lots and lots of "I believe" in there. He couldn't even be bothered to listen to it. It is no more authoritative than Vandersteen's anecdotal evidence. Is there any evidence that Richard Vandersteen does not use science in his designs? I would say that quite the opposite is true. In fact, he would say that designers that choose to not pay attention to phase in their speakers are absolutely wrong. He does back that with measurements. I am not saying either is right or wrong. I am just pointing out that many people here love to pick out the expert that they want to believe. You know, appeal to authority.

@vair68robert
See http://www.ielogical.com/Audio/CableSnakeOil.php. Jump down to Bi-Wiring if you don’t want to read the whole screed.

Bi-Wiring is provable and measurable. Audible depends on myriad factors.

Too many with zero technical skill or training hear phantasms, some chemically induced. Their posts are not worth the bits to transmit.

As far as millercarbons nonsense, after repairing, recapping & Bi-Wring my 35 year old Spica TC-50, and verifying I liked what I'd done with lesser cables, I spent 8x their original cost on Kimber BiFocalXL. Worth every penny.

YMMV depending on hardware and acuity.

Violating my own promise, I will make a few very simple observations:
For reference my system is quite extensive and has been tuned (e.g.: room, TT setup) pretty darned well, although i am not a maniac about it.
1. I have heard small, but meaningful differences between interconnect cables, and much smaller ones for speaker cables. real, but generally small.
2. I mostly heard difference vs cables that we would all agree are crap.  That's a technical term, but think generic, 40 year old, from some box somewhere int eh attic
3. I have seen myriad cases, in my system and elsewhere of cables that are basically broken.  Corrosion. loose terminations, poor contact etc.

I speculate that sometimes changing wires fixes these issues and is heard, but the reason is sim-attributed.
4. Want to improve wire gauge?  Make the wires shorter.  Now, to be honest, with an 8-ohm speaker impedance, or 30,000 ohm amp input resistance, does the difference between 0.05 and 0.03 ohms matter?  I'll leave that up to you.
5. Construction - e.g. dialectic material, is much more important than many other esoteric factors. I do go out of my way to use interconnects with expanded polyethelene or foam teflon or something similar. Its nto all that expensive anyway.
6. Many cables are so think and stuff that they place significant strain on connections.  I have seen many, many examples of bad connections because someone is using $500 cables that that thicker than my thumb and stuff as a garden hose. Oh wait, they were garden hoses, scratch that. In fact i have had to service equipment that was actually damaged by the strains (like expensive [brand omitted] terminals breaking... think about that)
And as MC said, in most cases the money and or time could likely have made a much bigger difference elsewhere.
having had too many Vandys to count, staring in the very early 80s, i never benefited from bi wiring BTW. Of course, since my system is also a test bed, i really hat to have complicated connections, rinnign from lab ot system and spending 20 minuets fighting with wires is not my idea of productive use of time. SO like i said, i'm biased.
G

I do not hear a difference on my Vandersteen Model 5As but it has been a while since I did a comparison.

Here is the real question that I spoke to Audioquest about.  Would I be better buying a more expensive run of speaker cable and using a set of their jumpers or buying a lower priced run of their speaker wire already set-up for bi-wire.  They advised me that their new speaker cable bi-wire line was better then a higher priced single run.  I did not ask why but that was their advice. I never did try it though.

Happy Listening.

Thank You All

I mentioned that 3 people converted ( added 2d pair of speaker posts )
to bi-wiring and liked the results .  All three had already upgraded the crossovers with higher quality components ,
I just got to the speakers yesterday ( after having installed the same 9.5awg wire from the amp board to the new Cardas speaker posts,
the same 9.5awg wire I used to put together my speaker wires )
when I installed Cardas speaker posts with the next upgrade it will be the wiring to the crossovers ,
one step at a time to evaluated the effect , the bi-wiring if I go that route 
would be the last thing I do .

It seems the experiences , opinions and even the manufactures are 
on both sides of the benefits or lack of .

I just have to wait until social distancing over so I can go over to my friends house and listen to his newly bi-wired speakers .