MEASUREMENTS: Nordost-like flat silver-plated copper speaker cables. And, comments of a "high-end" cable insider compared with an apologist?

Cables are fun to play with! They look different, there are all kinds of brands available, and for some audiophiles, there's a sense that the sound has been "changed" if not "improved" when trying products at different price points. All without lugging big and heavy speakers or amplifiers around which makes the upgrade easy especially if one believes that the change can be equivalent to such component swaps! Speaker cables in particular would be the most interesting because they carry complex musical signals of potentially high current and voltage for longer lengths. (Digital and power cables are least interesting for me for obvious reasons - here's my summary post of cable measurements over the years.)

I've already talked about a number of different speaker cables in the past; most recently here, here, and here. Notice that morphologically, all of them have been "roundish" cables so I thought it would be fun to try something flat and measure to demonstrate the LCR changes that this kind of design provides.

Looking around AliExpress, I found the cables above - China-made Nordost-like speaker cables - I bought the 2.5m pair with locking gold-plated banana plugs for less than US$100. There are similar products found on Amazon but you'll need to shop around for a good price.

I think the design of these are probably most similar to the Nordost Heimdall 2 cables which currently retail for about US$2,500, 2m pair.

Before running any measurement, let's have a closer look at this design...

As you can see, each +/- run of the cable consists of 9 strands of claimed silver-plated OFC wires. Each solid-core wire is specified as "0.7mm" in diameter or around 21AWG which adds up to about 12AWG combined. However, because they're silver-plated, this should conduct a bit better than typical multi-strand 12AWG copper cables. I believe the Nordost Valhalla 1 (from 2001) has 10 strands of silver-plated OFC for each run so that's a little thicker overall AWG-wise. The Nordost Heimdall 2 has 9 strands but 22AWG (0.64mm diameter) so the effective gauge is around 13AWG and might be of lower gauge comparatively.

In the picture above, you can see that there's a single threaded reddish Teflon "mono-filament" ribbon that's wrapped around each wire strand and supposedly provides a bit of airspace between the conductor and the polyethylene plastic shield. Within audiophile lore, there's belief that short of a vacuum, air is the best dielectric and thus "sounds better" for audio cables.

Here's a picture from Nordost's brochure of how this looks internally with that Teflon ribbon spacer:

There have also been discussions on forums about which material is better for anti-oxidation for connector plating: gold vs. rhodium. As discussed previously, while rhodium looks great and is a harder substance than gold (harder to scrape off), it is more expensive and less conductive (rhodium is ~50% as conductive as copper, ~70% of gold, gold in turn ~70% of copper). Since I'm not plugging and unplugging speaker cables all the time, my choice is to stick with gold plating for superior electrical conductivity.

I like locking banana connectors:

Loosening the screw-in piece allows you to put the banana plug into your speaker/amp without any metal scraping and then you can tighten the screw to improve contact. Some audiophiles advocate using spades or bare wires which are great; I think these locking banana plugs are almost just as good and I have had no issues with maintaining excellent contact over time.

So, how does it measure? Using the Reed R5001 LCR Meter, here are some results normalized per foot:

Very good consistency between the two cables which speaks to at least good manufacturing tolerances with this pair I bought.

Using the resistance/impedance at 10kHz, insertion loss across 10' of this cable (round trip, 20') into a 4Ω load would be a little less than -0.05dB. As usual with thicker gauge cables at normal lengths, this is simply insignificant.

So, what do we see from the data above?

1. Compared to a standard 12AWG copper cable like the KnuKonceptz Kord Cable (~2.5-3mΩ/ft across the tested frequencies), this silver plated cable does show significantly better impedance/resistance. This is a good sign indicating that the locking banana plugs, wire-to-connector soldering, gauge of the conductors, and silver plating are all performing to expectations.

2. No skin effect up to 100kHz. Notice that Rs does not significantly increase from 10kHz to 100kHz unlike a standard zip cord. For example, the KnuKonceptz jumped from 3mΩ to 9.4mΩ whereas this remained around 1mΩ/ft across the full range.

3. In a flat design like this, capacitance is nicely subdued at <10pF/ft. Conductors are kept apart unlike cables with closely woven architecture like the Kimber 12TC with capacitance of >100pF/ft which we can see in the knock-off version (and here) as well, previously measured.

4. As basically a straight wire, inductance remains well controlled. Some self and parallel-wire inductance is to be expected.

5. Due to the construction, it's possible that this cable is more prone to interference. This should not be an issue though because speaker cables carry higher voltage signals than analog interconnects or phono wires. If you're worried about this, check out cables like the Canare 4S11 star quad (inexpensive from sources like Blue Jeans).

Here are the Bode plots for 10' of this cable connected to a 4Ω load, plugging parameters above to model the filter network:

With mitigation of the skin effect, frequency response extends out nicely. At 20kHz, we're not even seeing -0.01dB reduction, and phase change is just beyond -2° in the simulation. This is literally smaller than microscopic; an audiophile will appreciate the insignificance of this if they've ever measured speakers!

Let's compare the results above with published Nordost Valhalla, Valhalla 2, and Heimdall 2 speaker wires:

Compared to the China-made "generic", the values are about in the same ballpark with low capacitance and even lower inductance reported by Nordost. I'm not sure if the Nordost values were obtained as a complete cable with connectors or not, and whether measured flat or with some natural twists and turns allowed as in my measurements. For even more fun, I also threw in the Odin 2 speaker cables' data - a mere $30k/m pair asking price.

It's unfortunate that we don't have any resistance/impedance values for the Valhalla 2, Heimdall 2, and Odin 2. Arguably, this is the most important measurement! Too bad because we can then get a sense of the total wire gauge. Instead, Nordost seems to think propagation velocity like "96%" of the speed of light (or 287.8 million m/s) is meaningful for some reason when it comes to transmitting audio signals in our rooms. 🤣

Flat cables in room with Topping PA5 Mk II+ amplifier, Paradigm Signature S8v3 mains and subs. Notice the tiny Class D amplifier in comparison to these wires!

"So how does it sound, Arch?"

It sounds totally awesome, friends. 😁

I mean, seriously, these cables conduct the signal well with basically no effect within the audible spectrum and octaves beyond. What is there to say other than this is "transparent" to the output from one's amplifier?!

Bass hits deep. Treble hits high. Transients tight. With impedance/resistance better than typical 12AWG copper speaker cables, these will easily handle reasonably demanding loads (should have no problems handling 20+A of current).

What is most noticeable however is that these will look unique compared to most other cables out there. And that esthetic difference might be worth having in your system. Your visitors will ask why your speaker cables look like that and you can bedazzle them with explanations about how you want to keep capacitance at a minimum because you desire resolution without risk of amplifier oscillation and the skin effect from thick round cables reduce ultra-high-frequency reproduction so you went with a silver-plated thin solid-core design. Voilà! Scientific rationalizations for hi-fi performance. Other great hardware audiophile discussion topics will naturally flow after that exposition of your knowledge in cable performance... 🤓

"But Arch, there are all those people on forums and Golden Ears in magazines and on YouTube saying they hear amazing differences between speaker cables! Can they all be wrong?"

Yes, of course they could all be wrong! There are literally millions of people holding extreme political and bizarre religious views out there who are wrong. While there might be strength in numbers, truth does not necessarily correlate with the number of believers. Some believe in "facts" without evidence. Other times, they claim to perceive things they hold true such as their deity whispering to them ideas they already were probably predisposed to believe. Our culture obviously plays a big part in how we're predisposed to think, including this nebulous "audiophile culture" we as hobbyists immerse ourselves in.

Does a rational individual need to consider every possible claim? Or engage in ceaseless debates? No, one just has to hold his ground and try to explain things as clearly as possible while pointing to evidence, without getting too emotional.

Here's one more bit of evidence that within reason, speaker cables do not change the sound in amazing ways. Here's a sine sweep of my left speaker (+ sub) connected to the Topping PA5 Mk II+ either to the DIY "Colorful Speaker Cable" (9') vs. this Nordost-like (8.2') flat cable. My usual room correction DSP turned off, measurement details preserved using only 1/24-octave smoothing:

We see slight inter-measurement variations as expected. However, it would be ridiculous to argue that the change caused by speaker cables being swapped out would have affected the frequency, distortion, or time-domain in these results to the point of obvious audibility! Certainly nothing here that should cause anyone to mistaken the sound of that same speaker in the same room or believe that I somehow replaced an important component. This is despite the very different construction between the two cables and measurable variations in resistance, inductance, and capacitance. Compare this to the effect that amplifiers can make even in just the frequency domain.

Even though these Nordost-like cables are silver plated solid-core strands, and we see the lack of skin effect, notice that there is no change in the frequency response. There are audiophiles who claim that silver makes cables sound "bright", sometimes even to the point of being "harsh". I don't know what cables or amps or speakers they're using, but I certainly have not come across that issue! The electrical difference between silver and copper is just 7% difference in conductivity with silver being better and more expensive. (A few years ago I measured the Slinkylinks pure silver cables as well and did not notice any frequency "harshness" there either.)

Electrons conveying higher audio frequencies are not able to go significantly faster or stronger than lower frequency signal electrons through the silver conductor, apparently. 😉

As you can see, these cables are missing the directionality arrows! I'm sure you can figure it out without the company telling you. 🤔

In summary...

I must say that I was actually quite impressed by these inexpensive cables from China. Often we won't really know the performance of things we buy off AliExpress so the ability to test is important to ensure that performance is as expected. For these flat cables, while I can't check on the copper purity (supposedly 7N/99.99999%), silver content, or whether the inner mono-filament ribbon is in fact Teflon, I'm certainly happy with the electrical performance I found. If you have never tried cables of this geometry and just want to listen without spending much money, these could be worth it (again, this is the link I bought from although I know there are others selling the same item, also monitor Amazon).

If you really want a fake Nordost, I see that there are expensive variants complete with wooden(?) spacers that might or might not be equivalent to the real thing. I'll leave it to you to decide on the morality of purchasing such items - in my mind, the whole hi-end cable industry including the asking price, and their claims of sonic benefits are already morally complex to begin with!

[As a company, Nordost also wants us to believe various questionable things like this blog post about Cable Burn-In. Even the idea that if a cable is unused for awhile, one might want to refresh the burn-in effect! Of course, companies are happy to sell you their burn-in service for close to $100. More here on the Nordost Vidar burn-in machine.]

You see, I'm not a cable "denier"! Cables are important, they obviously can be shown to have different objective performance depending on their construction, and without cables, one would have no sound. 😁

I can't deny anything when there's simply no evidence to reject, but I can certainly disagree with people who have strong subjective opinions about the effect of cables on sound quality. My recommendation is just make sure to curb one's enthusiasm around what you're expecting to hear between inexpensive and astronomically priced wires, that's all.

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To end, here's a fascinating comment from "Tim" back in 2015 on Steve Huff's article "Nordost Valhalla 2. The Importance of cables in High End Audio" (we talked about Huff's review of the Daniel Hertz products recently). Since this comment has been out there for awhile, let's quote it here for completeness in the event that the message gets lost in the future:

Tim says:

DECEMBER 22, 2015 AT 8:24 AM

Steve you’ve been sucked in. I make expensive cable. For a company you know. Here is the truth for any who will believe it over ego. Cable does make a difference. In all kinds of applications from power transformers to guitar pickups to interconnects we know there are strange things that happen with electricity. BUT we have no scientific understanding to explain “why”. Many theories exist and some truly long winded sales pitches. However science is science and in order for any theory to be valid it much be tested and verified. This is where every last person like me making cable and every company selling it falls short.

The truth of the matter is, the most honest efforts are shots in the dark. We just try stuff. I cant explain why this way sounds cleaner than that way … but I have experienced results for myself. However NONE of these results are that grand nor life changing. In fact all are small enough that the wax in my ears or level of sleep could change things more. The reason I got into cables was I am very experienced making high end product. I understand that unique is crucial to the high end tactile response on the buyers end. So when a certain company approached me I did a whole line. It went on from there because the profit margins are massive. Honestly – no one cares what the cable does. They only care how it will be perceived in hand.

This sounds very dishonest doesn’t it? It used to bother me. The truth is its a business like all others coined “Luxury”. Everyone in the chain gets a massive markup so everyone participates in the pitch. I used to lose sleep and even stopped doing it until I realized that the ego will make decisions with or without me. See, that is the only science of it any of us really know or understand. The human EGO will be satiated by cables. The force of the ego will create solid results in the mind. Like religion, its a powerful near unbeatable force. For many customers its their existence. We have a fanboy who has spent many thousand dollars on our stuff. He brings people in all the time. Simple civil servant, non descript, single, middle aged and this “golden ear” thing is his identity. Sad? I once said yes. But then Tiffany does the same with jewelry, Jaguar with cars etc. People like to obtain self worth via things. I can tell you that we have a line going up up up in price for a reason. Profits. None of it is about quality level. Its about once we get you on that train, we have seats for you until you want to stop. We don’t care where you end, we simply have that seat waiting. From $200 to $20,000 … there is some cosmetic costs due to unique manufacturing process but its all about tactile response. We don’t actually consider sound as we design upstream. Any change is accidental and we don't understand it any more than you do. Our design is about the mind. Perceive and you shall receive.

I can write this without issue because I know that people will choose their own path anyway. I could clobber the believer with a bat and they would believe. On the flipside the cheap cable guy isn't going to buy my stuff unless the mental process begins from within. That’s why cables are always available to demo from a dealer and then large discounts when you return. Its all profit. Cables do indeed sound different, but the value per $ spent is generally all BS based with accidental sound differences being up to chance.

This is long enough, I wont even go into the science of why our claims are mostly BS due to equipment cable is plugged into.

Tim, if you're around these days, leave a note!

That's one of the most well-written, self-aware posts I have seen from anyone purported to be related to high-end audio or the audiophile cable manufacturing business. Fascinating stuff. The cable industry given the prices they charge must be ridiculously lucrative if they're able to sell cables like the Nordost Valhalla 1 at MSRP (something like US$7,350 for 8' pair back in 2001). The writer is well aware of the power of consumer psychology/behavior that can be exploited.

I see Steve Huff responded to that comment with this (emphasis in caps his):

Steve Huff says:

DECEMBER 22, 2015 AT 8:42 AM

Doesn’t matter. I’ve done BLIND tests in my room with 5 others. ALL chose my Nordost Heimdall II (and these are mid level) over the $100 cable I had. IT WAS HUGE, and not just to me, but to all in the room. They had no idea what was what, but I asked them what they preferred. EVERY ONE chose my Heimdall II cable (speaker and IC) over the cheap brand, and it is night and day. If I remove these cables I do not even care to listen. Stage falls flat, details diminish, bass gets sloppy. It is what it is, and it’s easily noticeable. Each cable brings different characters to the sound, and what I have now I adore and wouldn’t change. I could care less if you guys experimented when making your cable, as I would as well. There is NO science with cable making, at all. As you said, it “let’s do this and see what happens” but sometimes that works out and delivers amazing results. Cable are just as important as some compnet upgrades. I experienced this MANY times. I wish my $100 cable sounded better or as good as I could save money but it is not even close. There will always be ANTI cable people like yourself and that is OK, a blessing actually. That just means you can save some money.

Compared to the thoughts expressed by Tim, that IMO is an unbelievable response that doesn't correlate to the world of controlled observations. This dramatic response is telling of Huff's character, who obviously is very biased towards industry claims. This is the kind of response one would expect from a "believer" rather than one who is capable of sober judgment - to me, his message sounds like it was meant to be in defense of the Industry, aligning himself as an apologist rather than one interested in truthful inquiry. It's hard to imagine that this comment is for the betterment of the consumer who is looking to explore the value of products.

Notice that Huff does not engage in any recognition that human psychological factors are important in the production and marketing of these kinds of products. I do not for a moment believe this man actually conducted a proper blind listening test because anyone who has, I bet, would show some humility at his own limitations rather than those ALL-CAPS dramatic and extreme claims ("Cable [sic] are just as important as some compnet [sic] upgrades." Which ones? Demonstrate even one example). Also, it doesn't help that he's obviously incapable of running measurements to confirm what he believes despite those cliché comments of "night and day" differences! In my opinion, false testimony is the greatest failing of any reviewer who desires for even a modicum of journalistic integrity.

Whether it's bit-perfect streaming that makes no difference, or the extreme luxury of expensive computers with no real possibility of meaningful effect, the "high end" audio industry indeed does have many "seats for you until you want to stop" with stratospheric price tags. My hope is that the truly rational audiophile can appreciate his/her own psychological drives and how this can be harnessed by companies in advertising (not just in audiophilia of course).

I think being smarter and wiser will lead to better decision-making. Your money. Your ears. Your beliefs. Your choices. 

Alright everyone, I have quite a busy schedule ahead so disruptions in regularity of posts might be notable through the summer months.

Hope you're all enjoying the music!

Addendum: June 19, 2024

LOL. Just came upon this Steve Huff video dated May 29, 2024 and it looks like he's recommending these $40/12' 14AWG Amazon zip cord cables now for "99.8%" of his viewers. Man, what happened to cables being as important as component upgrades? Or the idea that differences are "HUGE"?

If cables made a big difference in 2015, why now about a decade later with presumably even more advanced speakers and amplifiers, have the Nordost Valhalla become less important?! I thought the idea was that with even better, higher fidelity products, one could hear the effects of the cables even more? Guess not. Alternatively, it's possible that a decade later, maybe his ears aren't as attuned to the cable differences, a bit of tarnish on those Golden Ears? 🤔

Seriously folks, this is the ridiculousness of pure subjectivism with absolutely nothing concrete, just vague auditory memories and "feelings". His understanding of cables has gone nowhere in a decade because there simply was nothing there to begin with. No surprise.

If audiophiles felt encouraged by recommendations to spend thousands on Nordost products based on testimonies such as Huff's over the years, with expectations of large audible improvements, how should they feel now when all along, US$40 would have been adequate for a 12' pair!?