Have you considered that replacing the ratty old oxidized copper with ANY new cables would have made a big difference, and that star quad was not the only reason for the wondrous improvement in sound?

After changing two variables, you have chosen to embrace one, and discount the other.

Mark says,

“Replacing a 22-gauge twisted pair with two pairs of 24-gauge conductors connected in parallel produces the same DC resistance, but about half the series inductance.”

Uh, yeah, except that Star-quad cable has higher capacitance than standard twisted-pair cable, and higher capacitance leads to high-frequency rolloff, an effect that’s of course most noticeable as the cable length increases (at audio frequencies, this capacitance is a bulk effect). And this contradicts the next statement:

“This provides better clarity without the need for EQ to boost the highs.”

Oy.

Finally: “There’s also an improvement in phase shift at high frequencies, especially in complex waveforms.”

Please show me your work. Thanks.

Umm… You might also consider that some people might be plugging these wonderful 20’ mic cables into an everyday garden variety copper snake that’s hundreds of feet long.

I use starquad cable in preference to pair. It’s much better at rejecting magnetic interference. Well worth having if you do noise-critical events.

“With today’s growing RF transmissions, quad cables provide increased immunity to radio interference.”

Can you explain the above quote?
Surely it applies only if the cable happens to have better shielding, regardless of being quad.

Oh, and if your line drivers aren’t up to the job (very common) you will get less HF and a noticeable lack of brightness when replacing a long run of twisted pair with quad. It’s due to the much hgher capacitance.

Who’s marketing hype sneaked its way into your research, or did you forget to engage your filters?

“Most report clearer highs, less mud in the mid-lows, and a lift of the “haze” associated with previous mixes. Individual channels combine better, take EQ better, and compress better”

Wow, I read this in the print edition and was shocked that these kind of un-testable audiophile claims found their way into a Pro audio magazine.  In the future, please stick with testable, real measurements and let the audiophiles decide which $12,000 cable gives less “haze”.

John Huntington
http://www.controlgeek.net

The series inductance in mic cables is such a HUGE issue to be solved that Canare (originator of Star Quad)does not even list it in their cable specs.  They do, however, spec the capacitance, which is almost twice that of its comparable twisted pair alternative. More capacitance is highly unlikely to improve the HF transmission or decrease the phase shift.

Series inductance in a typical 10m 22 awg twisted pair creates 2 ohms resistance at 20 kHz (from Phil Giddings page 313). Do you think that’s going create “haze” at your 5k ohm console input?

Canare - Star-Quad is here =>
http://www.canare.com/ProductItemDisplay.aspx?productItemID=53

Canare twisted pair is here =>
http://www.canare.com/ProductItemDisplay.aspx?productItemID=57

The advantage of star-quad lies in EMI rejection by virtue of matching the centers of the pairs at the physical center of the cable (Giddings Page 318). That’s physics. More pairs = more capacitance- that’s physics, and that’s the tradeoff.

Less phase shift “especially on complex waveforms”?????? Is that because complex waveforms don’t fit inside the cable as easily?  At what point does a cable say…. geez this is just TOO COMPLEX, I am going to have to slow it down?

“Most report clearer highs….”  Please.

Well,
It’s an honor to have concentric circles painted on my back by such a noteworthy group of industry veterans. Let me make a few points that weren’t possible due to the limited space available in one page articles. First, all cables have some HF roll-off. Second, yes, the additional capacitance by doubling the conductors does induce some additional HF roll-off above 20 kHz, esp. in long runs, and is well documented. 100 meters produces 5dB attenuation at 50 kHz, so ten meters produces a half dB at 50 kHz. Third, Belden 8412 exhibits a similar HF roll-off to Canare Star-Quad due to its rubber insulation’s lower dielectric constant. Many modern systems today have their mic-pres on stage, shortening the length of cable runs significantly. The effects that I, and everyone on my tour in 1997, observed were as dramatic as I reported. My comments were also based on discussions with many others over the last dozen years. Are you objecting because you didn’t observe these effects, or do you simply object to my language? Tell you what; just keep using your 20 year-old Belden 8412. While you’re at it, keep using your 20 year-old 48-pair multi-core snake that’s been dragged across the parking lot 100 times a year and then stuffed back into the cable trunk by local stage hands dancing on it. I’m sure its Bel-foil shield is still working just fine. Not. Guess what; on the following tour we put our mic-pres on the stage.
  Let me try and help you: the average RF noise floor today is significant in comparison to microphone signals in the several millivolt range and improved EMI rejection does have an audible effect. Second, star quad cables cost more than regular two-conductor cables, about twice as much brand for brand - but not $12,000 - and there are less expensive brands, which use the same copper, polyethylene and geometry as the high-priced spread, and cost almost the same. Third, you’re right; some of these are untestable comments. So what? Does that change the fact that the sound performance is improved from a subjective standpoint? Here’s the point, which I think was lost on some of you: The least expensive improvement you can make to the performance of your sound system might be to buy a few dozen star-quad cables if you’re not already using them. That said, if the majority of your input list consists of wireless mics, playback and other line-level sources typical of modern ‘pop,’ ‘rock’ or ‘r&b’ events, it may not make any difference. Per the old chestnut, your mileage may vary. Good luck.
Now, where did I put my asbestos suit?

First, if you want to engage in an intellectual discourse, you should get rid of the attitude.  The condescension reflects poorly only on you.

“Third, you’re right; some of these are untestable comments. So what? Does that change the fact that the sound performance is improved from a subjective standpoint? “

You are apparently missing the entire point.  If what you heard 13 years ago was a real effect (certainly a possibility), then it should be testable, and verifiable using a double-blind test procedure, which would not be hard to do, especially for a mic cable.  Just close a curtain on stage, and have someone not involved in the experiment change the cable behind the curtain several times without any of the observers knowing which cable is being tested.  Then try comparing new 8412 (as you point out, older cables certainly could degrade performance) or whatever against the star quad.  If you can hear it, it’s real.  If you fail the test but still believe that the improvement was there based on faith, then you are an audiophile, not a sound engineer.

Not doing that and relying on testimonials is a sure path to self delusion.

And you should review logical fallacies here:
http://www.theskepticsguide.org/resources/logicalfallacies.aspx

John Huntington
http://www.controlgeek.net

Well Excuuuuseme,
Nothing like a good psw pile-on. Some of you seem to have extra time on your hands. Why don’t you take your favorite FFT program and measure a 50-foot XLR plugged into a 100-foot sub-snake, plugged into a 300-foot multi-core. Any observable roll-off? The effects I described in the article were not a complete double blind. However, we did three shows with 8142 and then replaced them all without telling the FOH engineer they were Star-Quad or the band that they were even switched. The FOH engineer noticed the difference, while the band all thought I had replaced the console. Your turn. Peace out.

“Well Excuuuuseme,
Nothing like a good psw pile-on.

One response is a “pile on”? 

“The effects I described in the article were not a complete double blind.”

There is no “incomplete” double blind.  Without such a test (or at least a single-blind test), either the effects don’t exist, or they do exist but you have no way to really know the true cause.  To wit:

“However, we did three shows with 8142 [sic] and then replaced them all without telling the FOH engineer they were Star-Quad or the band that they were even switched. The FOH engineer noticed the difference, while the band all thought I had replaced the console. Your turn. Peace out.”

Hmm, and NOTHING else changed from the third to fourth show?  Humidity, temperature, blood alcohol level of the band or crew?  Or, as you postulated previously, that the cables you replaced were worn out (with measurable effects, like old solder joints, degraded shield, etc)?

I never said that you didn’t hear something.  I never said that star quad cables might not be better.  But if we’re going to advance the science (and art) of sound reinforcement, then we need to do so based only on effects we can actually prove.  There’s enough faith-based practice out there in our field already, and a reputable trade magazine shouldn’t be putting more of it into the world. 

And, I’m working a gig (NY Philharmonic in central park) all week, but if you want to participate in a real double-blind experiment at my school, just let me know.  You bring the star quad, I have everything else we need.

But if you’re not willing to actually isolate real effects and deal with the actual results, or even admit that there is a possibility that you were wrong, then there’s certainly no point in continuing this discussion.  And that’s sad, because I’ve been reading your writings for years but have now lost respect for you. 

My crystal ball shows an ad hominem attacking coming…

John Huntington
http://www.controlgeek.net

Mark, to whatever extent that I contributed to a toxic atmosphere in this discussion, I apologize. My comments were not intended to be personal. I have long respected your work, and your writing.

That said I still feel that the article is below (what I believe) are your standards, which is what attracted me to comment.

Our professional audio industry has a noisy neighbor - amateur audio - AKA audiophiles. The consumers of that trade are willingly victimized by marketeers who make unquantified, unsubstantiated, unproven, undocumented claims, full of un-measureable made-up-terms that sound meaninigful. Their ad copy might read LIKE THIS:

The Retro-encabulator “can also improve sound quality. Most report clearer highs, less mud in the mid-lows, and a lift of the “haze” associated with previous mixes. Individual channels combine better, take EQ better, and compress better.”

No product receives more hyperbole in that industry (and bilks dentists, lawyers and doctors of more money) than CABLES.

Your article - not for what you left out because of article size limits - but for what you left IN - has a strong echo that sounds like audiophilia.

Statements such as
“There’s also an improvement in phase shift at high frequencies, especially in complex waveforms” are VERY hard to swallow for those of us that measure complex waveforms as a career, because we know that is not how waveforms behave. The claim sounds impressive - but is meaningless - and potentially misleading to readers.

The objections here are not disagreements over facts - they are the objections to unsubstantiatd CLAIMS. If we clearly delineate between the verifiable and the subjective then things will go down easier. Sometimes I think things sound better and I have no idea why. That’s fine, and until I find some verifiable cause, I will qualify my endorsement as subjective and unproven. That is all I would ask for in such an article as this.

Lastly, the fact that the band thought you had changed consoles sounds, at first, impressive. But is that the same band that asked us for more 2K, and then we reached down to the console and pretended to make a change? They thought that really improved things too.

I respect your work and look forward to reading more in the future. I hope that these comments will prove beneficial to the discussion.

PS: I have 800 ft of Canare Star-Quad that I use for my measurement mics. It measures just fine.

Well 6o6,
I’m sure you know I have enormous respect for your work and c.v. as well. The group I refered to was kd lang and her band, who I think you’ve met, which include Greg Liesz and Abe Laboriel, Jr. who is now Maca’s drummer and main backup singer. I kid you not when I say that without any prompting or exception, they asked me one at a time as they walked off stage before the encore if I had changed the console that day.
  Since you’re likely the best qualified to make these measurements, may I suggest you attach your 800 feet of Star-Quad and measure its response in comparison to a simple 10-foot jumper. I assume any effects are linear and will translate well to shorter runs. Several others complained about its HF roll off, which might be of concern to you and other measurement folks who are interested in HF absorbtion at very long distances and which you may may need to measure from time to time in large outdoor systems with those same cables.
  I’ll leave it to others to decide whether they replace the cables on their stage and see if it lifts a “haze.” No doubt it is too subtle for some ears. I’ve already proven it to myself. As recently as this past season with the Jacksonville Symphony Orchestra we were able to find the non-quad cables by listening for the SCR buzz. There are many professionals making daily multi-track recording who are in a good position to double mic their stage and use some scientific methodology to compare how 2- and 4-conductor wires affect their mix. Since quad mic cable adds less than a dollar to the cost of a 25-foot cable, it seems like a no brainer. Let me know, 6o6-san.

Part I (due to a character limit in comments I just discovered)

I don’t want to beat a dead horse, but I do want to clarify a couple things (I’ve been writing my postings after very long days out in the sun, and my brain’s a bit fried).  You may know this stuff already, but I’m writing this for the other readers of this thread too (if there are any

The kind of testing you have been discussing with Bob—real, technical measurement—is incredibly important, and is the way to test claims like “Star quad construction reduces the inductive reactance of mic cable”, or “...improvement in phase shift at high frequencies, especially in complex waveforms.” (although you would have to clarify a bit what an “improvement in phase shift” means—closer to 0 degrees?, and at what frequencies).  I do that kind of testing myself as much as possible up to the limits of my understanding (and then I call in experts like Bob! . 

But it’s also quite possible to do real, scientific testing with only the most important test equipment—your ears.  Its all about the process you use, and the claims you evaluate, and making judgements and moving forward based only on things we can actually prove.

For example, you have an excellent example in your followup—you talked about doing a line check and ID’ing cables (blindly, I would hope) based on the amount of buzz you heard in the PFL.  That’s an excellent test for two reasons: 1, it’s potentially at least single blind (assuming someone else set the cables and didn’t tell you which ones were star quad). And 2: you have a testable claim based on solid physics theories—“Star quad cables improve the ability of balanced microphone transmission lines to reject electro-magnetic interference”.  You don’t need a SIM machine to test that, just your ears. 

I don’t know the exact process you used for your test, but here’s a very simple experiment that would really nail down the truth, would cost only a bit of time, and could even be done while on tour.

1) While you’re not in the room (or in a position you can’t see the difference in the cables), have someone else set the stage, with 50% of the cables star quad, and 50% 8412 (or equivalent), all in similar condition, and tested and inspected for bad solder joints, etc.

2) Whoever set the stage goes out the back door (or to dinner, or to the bus or whatever), and you come in the front door (or have been at FOH while the stage was set and too far away to see what’s going on). You can’t even see or talk to the person who set the cables to prevent experimenter’s bias, see http://en.wikipedia.org/wiki/Experimenter’s_bias )

3) You go down the lines and attempt to identify the star quad cables using the method you described, and write down your answers.

4) You go to the stage and see how accurate your guesses were.

5) Repeat two or three nights on the tour to make sure that the cables are exposed to different EMI environments.  If you want to publish this, you might contact a statistician to make sure you have enough trials to be statistically valid.

That’s it, no test equipment, but if you can reliably identify the cables at significantly better than chance, then the effect is real (which seems very plausible to me).

This process—based on the scientific method—is what has gotten us to where we are today in the world, separating truth from delusion (both self and external). 

Continued in Part II!

Part II (continued from Part I—please read that first)

The test I was proposing to hold at my school would also produce real, challenge-able results with no test equipment.  I would have an instrument behind a scrim on stage, a good microphone, good PA, and a group (as large as possible) of listeners in the auditorium.  Ideally, I would use something like a yamaha disklavier since it’s an electronically-controlled acoustic instrument that can do highly repeatable performances.  One of my students would be behind the scrim, has been instructed to never speak during the test and has been shown how to change out the cables for the trials (quantity of trials determined by a statistician colleague—my stats are very rusty and I always sucked at math anyway). 

We start with lights up behind the scrim, and we listen to the 8412 micing the piano for a short performance.  We then switch to the star quad and listen to exactly the same performance. We switch back and forth as many times as people want, and people are free to discuss what they hear.  (Note: an alternative way to do this would be to record my friend’s disklavier in his house, with one recording on star quad and one on 8412 and then play them back in the theatre).

Next, the lights are brought up in front of the scrim and dimmed behind until we can’t see what the student is doing). We do this a number of (statistically valid) times, with the audience writing down their answers to questions.  The audience is not allowed to talk during this process so as not to influence each other.  At the end, we put the audience responses into a spreadsheet, and determine whether the audience was able to really hear anything.  If they did only as good as someone who flipped a coin would have done, then the effect is not real.

The important part I have left out here is which claims are we evaluating?  We could do an A/B/X test, asking the audience whether each trial was the star quad, or the 8412, based on what they heard in the non-blind part of the process.  If the audience can’t do better than chance at this test, then there is no effect.  If they can hear an audible improvement with star quad, then we could move on to test other claims, to try to get at the mechanism of what’s going on (that’s when we need Bob .

Now here’s the problem.  If I have 100 golden-eared sound designers in the room, would they all agree on what “haze” sounds like?  Or what something like “take EQ better” or “compress better” means?  You would have to narrow those claims down. I’d have to think of a more complex experimental design to test something like “Individual channels combine better”, but I’m sure it’s possible to test that too.  If we can’t test it, then we can’t ever know for sure if what we are (really) hearing is (really) caused by what we think is causing it.

In my opinion, as audio engineers, we should stay completely away from audiophile terms because they are meaningless.  And any time we use those kinds of terms we are supporting snake oil salesman (who may, in fact, believe their own hype) to rip people off (as Bob described), who specifically choose technical-sounding terms that can NOT be tested (Improved “soundstaging”, more “air”, etc.)

BTW, if anyone’s interested, we are doing some real double-blind testing this October at my school in conjunction with our Gravesend Inn haunted hotel.  Our experiment involves a bit of deception so I can’t fully explain the experiment until after it’s over (but I can say that after an exhaustive process, the experiment was cleared by my school’s institutional review board and that anyone reading this exchange would likely find the results interesting.)

Whew, that was long!

John

p.s. I coiled a whole lot of star quad on the NY Philharmonic stage last night

Oops, sorry, editing error! 

I wrote:
Next, the lights are brought up in front of the scrim and dimmed behind until we can’t see what the student is doing). We do this a number of (statistically valid) times,

Of course, by “this” I meant “trials”, not changing the lighting