Thoughts on Bi-Wiring on the XPA-1

[TKO]

Sept 12, 2013 19:28:46 GMT -5 audiosyndrome said:

Looks like it's time for my semi-annual bi-wiring spiel. I'm re-posting from a much earlier bi-wire (flame) thread. I've said many times, and observed, that bi-wiring may work, but the effects are subtle so your system has to be up to the task.

From Physics, an electrical current flowing in a conductor produces a magnetic field (the FBI rule where F is force, B is magnetic field strength in Gauss, and I is current). Therefore, the current flowing in our speaker cables produces a magnetic field.

This magnetic field varies in accordance with the signal being delivered to the speakers. In particular, the magnetic field of the slightly stronger bass frequencies interacts with the magnetic field of the slightly weaker high frequencies (known as intermodulation distortion IM). Bi-wiring can eliminate this distortion.

How you might ask? By physically separating the magnetic fields of the high and low frequency current. This separation is done in two steps.

1- removing the links between the two pairs of speaker binding posts, thereby totally separating the mid/woofer crossover from the tweeter crossover. Since I=E/R, or more correctly E/Z, and since Z is different for each leg of the crossover, a different current flows in each speaker cable.

2- running two sets of speaker cables to the (now separated) binding posts. The two sets of cables should be separated by an inch or two minimum.

Step 1 directs the low frequencies to the mid/woofer crossover and directs the high frequencies to the tweeter crossover (electrical separation).

Step 2 prevents the magnetic fields from modulating each other as they are physically separated.

Note that Step 2 is just as important as Step 1. If the cables are not physically separated bi-wiring will not work. Two cables in one bundle will not work.

Bi-wiring has nothing to do with skin effect, wire gauge, current in/ current out, etc., only IM distortion due to the magnetic field effect.

Note that Audioquest in their advertising for their Gibraltar (bi-wire) cable state that "it provides almost ideal isolation between the magnetic fields of the bass and treble current". Almost ideal because both conductors are not separated from each other.

Also note that Mapleshade and Insound recommend speaker cables be eight-feet or longer to eliminate the back EMF problem; a real problem.

Russ

Others disagree scientifically -- Superposition principle.  The first paragraph explains it rather eloquently.

Cheers.

[mpow3r]

So, all this being said... I guess I will order another set of Emotiva cables and bi-wire for the heck of it. Worst case scenario is that it will just look cool.... hahah!

[bulldozer]

I would do the same, it certainly will not do any harm .