HELIX Spec's

Its More Than Just Numbers - Isn't It?

This post addresses the electrical measurements of the three Helix Cables - Interconnect, Speaker and Power cables.

Having said that, the table below is simply a “guide”, since the values depicted are specific to the cables measured.

Minor differences can be expected due to variations in winding the helix, cable length, wire used and sleeving used.
e.g, one person has measured the capacitance of a 0.75 meter interconnect to be around 34 pF

The cables YOU build may not have identical numbers, but they will be fairly close, provided you use similar techniques, parts and wires.

Also - the numbers below are for cables of a specific length. So you will have to estimate the numbers for your cables if their length differs from those in the table

e.g. if YOUR speakers cables are 2 meters long then the numbers can be estimated as follows...

Capacitance: 181 / 3 x 2 = 120pf
Inductance: 3.2 / 3 x 2 = 2.13 uH
X
L @ 20 kHz: 0.402 / 3 x 2 = .268 Ohms


Specifications

Loop Inductance - is measured across the cable at one end, while shorting cable at the other end,


If you really want to get into the science take a look at this link...
http://www.epanorama.net/documents/wiring/cable_impedance.html


So - what do all those numbers (metrics) actually mean?

Rather than delve into complex formulas, I thought that comparing the Helix numbers to other well known commercial brands of cables might be easier for readers to understand, e.g...

  • The 60 pF/meter capacitance of the Helix Speaker Cable is significantly lower than some cables from Kimber Kable and TOTL Cardas cables which often exceed 300pF/Meter. This is important if connecting to a high current solid state design amplifier.
  • The 1.1 uF/meter inductance of the Helix Speaker Cable is higher than some other brands, but NAIM NAC A5 cable is rated at 1.0 uH/meter (highly recommended by NAIM). I own a NAIM amp and the cables appear to work very well with it and also with some other brands that adopt a high current design philosophy
  • One of the few companies that seem to have been able to keep both Capacitance and Inductance to very low levels is Nordost - however, a fellow DIYer’s that tried the Helix promptly sold off their Nordost cables in favour of the Helix - go figure Happy

The Helix “numbers” are Middle-of-the-road for each cable type, but based on feedback from others who have tried them, they appear be a good match to a lot of audio components. (see “
IMPORTANT:” below) and will minimize many of the effects that conventional geometries suffer from.

The Loop Inductance of the Helix Speaker Cable,
may be higher than other cables out there, and some people may believe this to be an issue.

However, I believe that this does not present any problems, when you consider the frequency range of a person’s “normal” hearing abilities lies between
20Hz and 12kHz over the age of 50.

As opposed to the generally accepted audio industry standard of
20Hz and 20kHz

Of course - if you are a teenager with excellent hearing you may be able to hear as high as 17kHz, (and perhaps a little higher) at which point you may observe a very small decrease in volume in the
15kHz-20Khz range

And if you are an engineer in one of the many companies out there that promotes frequency response of their components to be 0Hz to 100kHz - then these cables may NOT be for you.

There is some debate as to whether the additional 5% (of the speaker impedance) on top of the actual speaker’s impedance would be noticeable. e.g.,
  • my speakers have an impedance of 6 Ohms
  • 5% of 6 is 0.3 ohms
  • if I look at the impedance of the my 3 meter Helix cables from the table above = 0.402 Ohms @ 20kHz
  • So - If I could hear a 20kHz signal I “might” detect a tiny drop in volume
  • BUT - my hearing ability has diminished over the years, so taking the 12kHz value of 0.241 Ohms
  • I am well within the 5% margin
  • BUT AGAIN - this is not a hard and fast rule, simply because the crossover employed in the speaker may have a significant impact on whether any cable will sound good - OR NOT!
  • I have not heard of any negative feedback from any of the people that have tried Helix cables in systems ranging from sub $1000 systems, to systems exceeding $70,000

I have posted the Helix numbers above - because I have been asked for them many times, however...

Cable metrics should be used ONLY as a guide!

They ARE NOT a substitute for actually - LISTENING!


IMPORTANT:- electrostatic speakers is an area I have NO experience of, so I would strongly recommend anyone looking at using the Helix Speaker Cables with electrostatic speakers to look at the statistics above and assessing their possible impact before building or connecting Helix Speaker Cables

OTHER STUFF:

I have also observed that the Helix design actually enhances the operation of the components they are connected to.

e.g. most of my components run a few degrees cooler than with other cables


So right about now you might be thinking that these issues only apply to areas where the voltage and current is of significance, as in power and speaker cables, but regardless of cable type...

ALL CABLES ARE AFFECTED !