[written by Jeff with some revisions by Bob Howard]
Cable design engineer Galen Gareis has been testing and analyzing, parallel speaker cable wiring. Essentially this uses two cables in parallel for each channel to reduce inductance and resistance.
Galen had me build several assemblies that he then tested for actual comparisons.
This testing was at first based on several of the speaker cables available as both BAV and Iconoclast branded products.
One assembly that I sent was Belden 1310A. Some may recognize this as a “star quad,” four conductor 14 AWG that in some ways is similar to other “branded” product. In particular I had been working with this cable targeting certain REL subwoofer applications but I soon saw and recognized the potential for other speaker assemblies. The REL subwoofer cables are now offered on our site representing a great enhancement over the OEM cables and with a significant saving in cost.
Galen then had two regular assemblies connected together to a single set of bananas as a sort of adapter. I figured that wouldn’t be very practical for most folks who would want a clean assembly with as few connection points as possible and may not be able to ‘stack’ spades onto single posts.
When the results were revealed, we were all very pleased to see how well the 1310A performed in a star-quad configuration as a single when compared to 1313A but in particular in “parallel.” On June 23rd Galen published a technical bulletin that presents the procedures, parameters and results of his work. This data was presented on the PS Audio Iconoclast by Belden thread and is available to anyone who asks. Science and math, no snake oil here.
Galen’s review and testing revealed that 1310A in single or “parallel/dual” is measurable and quantitatively a significant improvement over Belden 1313A. The Belden 1310A product offers a number of application specific and performance enhancement options.
Consider the double/parallel application as the ultimate “tweak” for performance in speaker cable. The application of Galen’s test data applies to all speaker cables and not just to BAV and Iconoclast. Is not for everyone but the data is impressive. Listening tests from customers is unanimous.
Iconoclast tech Andrew suggested it be called ‘Octo-Quad,’ which we like very much. To me, this invokes images of a giant octopus living in Puget Sound. The name stuck, and going forward this special cable assembly will be referred to as such. We now offer the Octo-Quad assembly as a new addition to the BAV product line.
Here I would like to show you the step-by-step on how I built this beast.
First is measurement- I am going with 5 foot for this set. Lengths should not be too long for this assembly as the capacitance can get quite high. I am measuring right at 5 feet feet so the electricals are as close to 5 foot as possible. Two cables for each channel of course!
The next step is the techflex weave. I like this because it keeps everything together and gives it a nicer look. I’m going for 5 inch leads on each end, with a little bit of overlap between the edge of the jacket cut and the techflex ends. A hot knife keeps the cut on the Techflex looking nice and clean.
Now, I remove 5 inches of outer jacket from each end, exposing the insulated conductors.
For this cable we have four wires, color coded red, green, black, and white. To get the star quad configuration, it is necessary to pair up the wires that are across from each other rather than adjacent. Here would be black and white combined for the negative, and red and green for the positive. I’m going to heatshrink it over anyway, but this color coding is easy for me to remember so I can be consistent all around. I have also stripped the ends to expose the copper. Since I have to fit it inside a banana, I need a long strip length- 7/8″. If I was terminating with spades 5/16″ would do.
Now for the crazy part- I need to combine the two cables in parallel, so the two black/white pairs need to get wound together- same with the two red/green pairs. Each leg is now made up of four 14AWG conductors- that’s an 8AWG aggregate!
Each leg is bound together with heat shrink. Because of the way the individual wires come from different points the heat shrink can’t go all the way to the outer jacket cut, but since I left a little extra techflex that gap can be covered. The heat shrink needs to go a bit over the copper to make a smooth taper into the back of the banana. That’s a lot of material to fit in one connector!
Now I can cover the jacket transition area with a larger piece of heat shrink. Since Techflex is sensitive to heat I am covering the exposed part with a rag. Underneath the little bit of melt will make a nice finished look without too many bumps.
Finally I weld on the banana. Because I have stripped the wires back more, but covered a bit of them with shrink, there is plenty of copper to weld leaving no gap at the back of the banana. Took some trial and error to get that just right! I wasn’t sure how much weld energy it would take but it turned out to be very close to the amount we use for 10AWG, so that made it easier.
And here is the final result! It’s on the heavy side but more flexible than I would have expected. Electrical tests show a capacitance of 86 pF/ft, .06uH/ft, and .01mOhm. See Galen’s paper for more on the electrical theory. This set will go home for some listening tests.
It’s always stimulating to do work like this, and having been doing cable assembly for almost 17 years at Blue Jeans, any challenge is welcome!