Speaker cable geometry question


First of all, I'm sure this has been asked somewhere but I couldn't find it.  I have been out of the loop for a while and have just gotten back into the hobby and am looking for an answer on this (because I am just curious).  
Most speaker cables consist of any number of geometries in a single run from amp to each speaker in a single sheath.    Some however have single runs of + and - to each speaker.  Such examples include certain Purist cables such as Dominus and Neptune, Jena Labs and Nordost.  I am sure there are more but these are the ones that came to mind.
What is the advantage or disadvantage of doing a cable run in this manner.  These are very expensive brands and I've been rekindling my interest and this is one area in which I have developed a particular curiosity. 
nutella

Showing 1 response by drblank

A cable is an LRC filter or "network" as the resistance is from the wires, the Inductance is from how the wires are twisted, and the C is from from dielectrics used.   LRC measurements do change when the cable is loaded vs unloaded.  But a cable, if you think about, is a filter much like a EQ is a filter.  The only problem is to change how the cable filters the signal you have to change the cable geometries and materials. But MIT adds additional LRC networks wired in parallel to improve how the cable is filtered to achieve a more linear cable that gives proper texture, note and instrument separation, detail without fatigue, etc. etc.

If you read and watch various interviews and explanation of what MIT Cables has found out is that when they do their "articulation" measurements which is looking at the rise time (attack), settling time (decay) and amplitude of various frequencies in audio, the differences in the cable will yield a different "articulation" curve.  They also look at phase angles, noise, etc.  They are adapting articulation measurements developed by Bells Labs and applying it to audio cables.   So depending on the cable, it will produce a different tonal quality and some cables sound bright, edgy, etc., some sound more neutral, some sound more bass heavy. So it's just a matter of picking the right cable geometries, along with using a variety of different gauge strands of wire, shape of the wire (some use flat, some use thin round, etc.) and they are just playing around with cables to sound a certain way.  The thing to realize is that people prefer a different type of sound and everyone's equipment is different and it's a matter of matching the cables to one's equipment to one's preference.  Some people are very sensitive to high frequencies and they don't want an edgy sounding cable, but some people do.

MIT and others like Transparent, for example, simply design LCR networks, they wire in parallel to achieve a more flat "articulation" curve with as much texture.  They can achieve it a lot easier in that they have more control over the design of the LCR circuits, how many to add, and what frequencies to tailor them around.  But some people don't like the boxes as they can be a little difficult to deal with. 

But those that don't use those network boxes have to achieve a desired sound by changing the cable geometries, and materials.

If you watch the video from MIT, called What's inside the box, it talks about this as it applies to cables in general and then they explain what they do.  So it's a part marketing and part technical explanation for the average consumer to learn from. I think it's also used in their dealership training.


I hope this helps.