Why do you think Bi-Wiring improves the sound ?

Here we go again with insecurity of. The audiophile 
This remind me of the series of Tarzan and the witch doctor does the electrician are certified?does he pass
the board?come on this is the kind of person of the bunch that think his ability is unquestionable with no knowledge what is doing and the worse is trust your
gear to them to perform barbaric repair enough lets get to the point first the dedicated ac circuits from the
rest of the of your home is to cancel noise from the appliance from your house like frog air cond microwave is audible and that you could hear in your
hi end gear take an oscilloscope and test your ac outlets and detect for noise in the line of voltage and see the wave is with noises in different Fq that one 
number two copper and silver and gold are the best conductor and have their advantage in the spectrum 
I use Siemens breaker and ac outlets and solid core
copper and a separate Ground rod isolated for protection and keep safe your gear and also improve 
your sound quality of your system if you have an apéndice remove you go to the surgeon not to the witch doctor unless your electrician use trump desinfectant to clear your your ac anomalies go ahead I am a electrical eng with 50 years experience 
and also an audiophile when you hire somebody be sure is a certified profesional not a street barber

Well tabonuco  could you reword that in English please? 

danvignau

No I did not add speaker posts , have not modified the cross over boards .
 The question was does bi-wiring inprove the sound ?
I should have asked if bi-cabling or 2 seperate runs of cable sound better ? especially if you used one cable for the positive and the other for the negative posts  ( have any of you tried this set up ? )

My speakers have 2 crossover boards ,
one for the bass and the mid/tweeter is seperated on one board ,
sharing the speaker wire input , easy splitting for bi-wiring .

If it is easy, do it. What can it hurt to find out and know for yourself? If it were a PITA to do, then I would have the same concerns your OP had. But since it would be an easy experiment, do it and report back. You know that further contributions to this thread will continue in the same vein with those advocating one or the other side. (as usual). Have you EVER seen a subject when it comes to our hobby where there is a reliable and absolute consensus? At best these questions are an academic exercise. At worst they are contentious arguments.

I have come to realize that all the opinions, reviews, theories, experiments, discussions in the world do not trump my own experiences. I am the only person who knows what I like and want. And it is EXPENSIVE and time consuming to go through this journey. But your particular situation here is not all that expensive nor time consuming to try. In fact, it could have been done in the time it took this thread to peter out. 

And my reading reviews has done more harm than good for me in the outlay of money department.  I really have not improved the sound of my stereo since 1984, even though I have been through over a hundred components. I have circled back to a very similar system I had back in 1984 much to my satisfaction. If only I had just left it alone. 

A technically good amplifier is like an ideal voltage source with a low output series resistance and able to supply whatever current a load (wire, crossover, drivers) require. The problem is that the long wire presents a series resistance and inductive load with some shunting capacitance which causes the signal at the loudspeaker end to be different from that at the amplifier end, depending on the current being drawn. Even this is a gross simplification. Engineers model elements of a system to be good enough. Enough for what?  Enough for realization of basic function and requirements.  This doesn't mean that a power amp with a DC supply that can deliver 5A at 50V is perfect even though that supply meets its' specifications. In your computer chip, to ensure that a logic gate triggers when expected.  As those systems get smaller and faster, the models have become more and more sophisticated to satisfy basic functional needs.  
Separating the upper and lower sections of the loudspeaker crossover from each other (requires separate terminals) will allow parallel runs from the amp to the speaker. The most basic factor is that, all things being equal two sets of cables will halve the series contribution of the wire to the system signal disturbance. This can also be achieved with a shorter run of wire.
The bi-wire improvement will mostly come about because the high current woofer load distortions will no longer generate a voltage disturbance signal at the tweeter since they will not be present at the high terminals or at the amp terminals (assuming the amp is not a tube type with high output impedence). I could beat this to death but a simple circuit analysis using non-ideal elements will show this. So much for the assertion that there is no science, or more accurately, technical basis. Many people learn basic I=E/R and think they understand everything. A loudspeaker is not a simple 8 ohm resistor, a cable is not equivalent to a small resistance, and I=E/R are not frequency independent.  
Years ago, I used to argue vehemently, as an arrogant, self-assured electrical engineer, that power cords couldn't make a difference because the amp converted (rectified and filtered) AC into DC.  My model must have been too simple since after finally trying different power cords and conditioners my reaction was: "No freaking way!". I've since come to see that the amount of benefit of a power cord depends on the application. I've found the biggest improvements with high power class A amps which are always generating large current pulses, and for relatively noisy components like DACs etc. My preamp was not very sensitive to the power cord since it utilized a sophisticated DC bus followed by a 400 Hz AC system which was then reconverted to DC.