Paul McGowan writes:
One of my readers asked a very legitimate question: one that is asked on an ongoing basis and it refers to my post about cables. “Help me here. I do believe a roadblock to a broader appreciation of our hobby is the perception that the high-end audio industry is lubricated with snake oil. Cables are often mentioned.
I read an editorial awhile back in, I think, Stereophile that speculated that if PT Barnum were come back to earth it would likely be as an audio cable salesman.
My own strategy for immunization again snake oil is to insist at a bare minimum that there should be a SCIENTIFICALLY PLAUSIBLE explanation for why an audio product could offer superior performance. If I see audio cables with arrows in the connector for directionality, I run. Maybe I’m naive, but it seems all I should care about is low values of R, C, and L across the audio band. If any of these aren’t low, that cable might sound different. I get that. But I’ve got to think any well-made audio cable will have low values for R, C, and L.
So here’s where I need help: what physics could be responsible for the dramatic differences you and others observe?”
Well, certainly that’s the $64,000 question isn’t it? And, as an engineer, it frankly offends me that if we use a cable with proper values of L, R and C (and I’d add shielding and decent connectors to that) that it wouldn’t just work the way we expect – and in large part it does – but if we make an A/B of two cables with similar characteristics they sound quite different. And yes, they sound different turned one way or the other and to add insult to injury, the signal is AC! This means it is traveling back and forth through the wire so it shouldn’t matter. But it does. And I don’t know why.
In my case it was a blind test, since I had forgotten I even made the change. I went into the listening session with a mental picture of exactly what the system “should” sound like – and my only hope was that nothing had changed. Things changed dramatically – fortunately for the better – but in a reference system, it’s important to know just what has changed if it does and I couldn’t rest until I figured it out. The cables between the turntable and the phono preamplifier were the only changes. Going back and forth proved that to me quickly.
What exotic test equipment do I use? Just my own personal reference system in my head.
If you’ve read this series for any time you’ll know that the method I (and others) use to “measure” and reference the sound is based on memory. It takes a lot of time and I spend literally weeks listening to many, many known reference CD’s, vinyl and stored music on the system to get an image in my head of what to expect, how it sounds and how I react to it. Any student of human behavior will verify that this is something we all do in one way or another – children memorize the sounds and patterns of their parents as well as their environments and can instantly tell when even the smallest sound has changed – I do the same at home. I unconsciously memorize the sound of every stinking detail in my home from the sound of the water running through the pipes when a toilet flushes to when the sprinklers are on – it doesn’t take me too long to recognize a change in the pitch, the pressure, the length and related events that should cause these to take place. I am not unusual, we all do it. Amazing how many people know something’s amiss with their cars, their environments, etc. all based on sensory memory.
So with those facts in mind, it’s the way I can tell when something’s changed even if I don’t know what caused it. Some people I know, like my friends Arnie Nudell and Bascom King, have memorized the sound of acoustic instruments so well (from a listeners position) that they can translate those memorized patterns into right or wrong on stereo systems they aren’t that familiar with.
I bring all this to your attention for a couple of reasons: first, it’s important to understand HOW this is done and secondly, because it shows why the silly double blind tests don’t work for most of us. Our “test equipment” is based on sensory memory that is developed over a long period of time – and that only happens when we are receptive and not under pressure. Double blind tests plunk the listener down in a foreign environment, put the listener under pressure and asked to “choose”. It doesn’t work that way.
As to the physics of it – I am not an expert – and I don’t know that one exists. The guys that designed the cables I mentioned must know a lot better than I of what works, but as to the physics? Maybe Bill or one of his folks will chime in and help.
If you ask me the physics behind taste, I can tell you what I sense and my taste memory is really quite good – as a wanna be chef – and I can pick out very minute details and differences I sense for flavors that perhaps I haven’t had for years. In the same way, I can generally hear whether a car has a 4-cylinder, 6 or 8-cylinder engine – I can also still hear the difference between a Carter AFB carburetor or a Holly progressive 4-barrel on a car going down the street – so good is my sensed memory of such sounds. I believe all of us have experienced a familiar smell, sound or taste we instantly recognize despite the fact it may have been years since we experienced it. I cannot tell you the physics behind it, but I know from personal experience it is true.
The question being asked is an extremely valid one. That we hear these differences is irrefutable – that few if any of us understand the physics of why is a shame – but it doesn’t diminish the facts.
I respect you wanting to run away as quickly as you can – for you’re right, there’s a lot of expensive oil being sold – heck, my daughter in law paid $25 for a bottle of organic baby shampoo that no doubt started life out in a tanker truck – and most of us were raised on a bar of soap – but despite the amount of oil you’re running from, my advice to you is to help the industry discover the why of the physics if you can add to our understanding.