Observations of a controlled Cable Test - Page 13

So the time factor is ONLY interesting when the test is blindly? The same time, changing the cables, in the OPEN test was good enough, so why not good enough in the blindtest??

The switch box can be proven to be transparent at the frequencies of interest by well established scientific testing.

However the cable advocates denounce the scientific measurments. Well they don't exactly dismiss them as it's pretty hard to argue with the laws of physics. They rather claim the testing fails to measure "something" that is unknown which is in turn making the audiable difference.

Why not use the preamps A/B switch? You've got the same amps with different cables hooked up. Most speakers are designed to be bi-amped so each cable could be hooked up to the speaker at the exact same time. Of course if your preamp puts A & B on at the same time you might lose your speakers.

This is funny because it's true. When you read a review the differences are night and day, even though they may have spent an hour switching out cables. On a blind test, 30 seconds is too long to remember what they just heard.

You'll have to ensure that the levels don't change when using the A/B switch with respect to L/R and absolute.

NIN74
Quote:
"So the time factor is ONLY interesting when the test is blindly? The same time, changing the cables, in the OPEN test was good enough, so why not good enough in the blindtest??"

No, no, I am saying in both blind and open. I am complaining only about the time factor. I think in tests with a time delay, the supposed differences heard are entirely imagined. Probably would be so with a "perfect" switch, in a perfect test as well. I would completely prefer removing the subjective and using measurements alone and using "best case" audibility findings to weight the results.
An Examplehttp://www.audioxpress.com/reviews/m...hansen1203.pdf
This tells me I should not be able to hear a difference, the differences should be too small.
Skip the listening tests.

the point i keep making is this... if one thing sounds different than another, then they sound different. if they are different, then we can measure that. play a passage of music with one cable, then with another, use the state of the art measurement stuff, cranked up past audibility for resolution, then compare passages on a computer. easy to do a differential measurement. If they are different, within 20-25K and within .1dB, then i could concede that there was a difference. but at 40K with a .003 dB difference... give me a break.

I am not proposing measuring the cables, but the sound that comes out. it would be easy to show electrical differences in the cable, but in the audible spectrum... not so much.

The argument I've heard against measurements is that their is something the human ear can hear that a microphone can't.

Yes, stuff that's not there.

It's true that a single microphone can't capture 3D spatial information -- a single ear has a tough time with too. But an array of microphones can.

And microphones can CERTAINLY be designed to capture frequencies that ears utterly cannot detect.

So just what are these mysterious properties of sound waves that microphones can't yet 'hear'? I'd like someone to describe them.

Well, they only work well if the diaphragm is at least gold plated, but pure gold would be even better. Silver sounds bright, and copper can be too warm and slow.

I think this conversation is kind of going far afield. Discussions that we can measure the impact of a cable or a switchbox on the signal, and thereby verify its audible transparency, aren't particularly productive in this context. And what context is this? It's the context of an argument between people who believe in that science, and those who do not. So for the purposes of the debate, then, talking about a priori measurements is assuming the premise.

Let's face it, it's the same old discussion! It is simultaneously preaching to the choir of objectivists and tired old nonsense to the subjectivists. Kind of boring for both, actually.

So if we're trying to actually accomplish something new, we objectivists have to find ways to meet subjectivists on their turf. Give them as much reason to be comfortable with the testing conditions as possible. Give them as much rope as possible---to hang themselves with, of course.

This is the part of the approach of the James Randi foundation's $1MM challenge that I liked so much. They worked to hammer out a protocol that was acceptable to both parties, and they bent over backwards to accommodate the challenger's requests, as long as they didn't compromise the validity of the test. Granted, most of the challengers still figured out a way to bail out and accuse JREF of cheating. But the ones that went through with the test, as their video documentation shows, were treated well.

One of the ideas they promote is requiring the challenger to pass a non-blinded version of the test being proposed before they proceed to the full blinded test. That is, every aspect of the test protocol is put in place except for the blinding, and the challenger has to demonstrate they can perform under those conditions. If they can't, the test doesn't move forward.

Relating that to audio... so we need a switchbox? Fine. Put one in place. Sure, it might affect the sound (objectivists roll their eyes). But maybe the subjectivist will still hear differences between cables with it in place anyway. Maybe the differences will be made more subtle (still rolling). So give the subjectivist as much time as he wants to train to these new conditions, to find material that does the best job of exposing the differences that are left.

If he is confident that he is able to resolve differences, great! Put the blinds on and go for it!

If not---well, the tests ends before it starts. Yeah, you may not have been able to prove what you'd hoped to prove, but at least you have demonstrated that a an extremely-electrically-benign switchbox can obliterate all of the perceived improvement of a $30K pair of wires.

It's not the definitive smackdown an objectivist would love to see---but then, it's more than you'll get by boring a subjectivist to sleep with talk about frequency responses and impedance so that they lose interest in doing anything.

Michael, that's always been my tack. Test existing claims of audible difference, don't go 'looking' for new ones (which would be basic research, not claim-testing). That means the difference has to be 'heard' under the sighted portion of the test, and it means we should let the listener use whatever gear and timeframe he wants, then add the double-blinding when he's ready to be tested.

Although more laborious, one could first put the switchbox through a sighted and blind test to assure the audience it has little or no effect. If I remember correctly Noussaine has used that initial step in the past.

Well, if a passive switchbox causes cables to be inaudible, then everyone is screwed since all preamps have an even lossier switchbox in them. Therefore, buying fancy cables makes no sense.

To put a switchbox through a DBT , using a recommended low-latency method, you have to use another switch to put the switchbox in and out of the circuit -- e.g., the one in the preamp.

If passive switches are so heinous, it's a wonder anti-DBT skeptics tolerate listening to any gear at all.

I completely agree with Michael about doing the open test with "positive" results before moving to dbt. I do think it might be possible that replacing the memory of the observation with a very immediate switch would change the landscape of the argument to a larger degree than we think. But you have to get "serious names" to submit to testing to have the subjective audience to listen. Not holding my breath.

test gear cannot tell us if it is better, more airy, whatever. but it can tell us if it is different. and that is the heart of the discussion

Test gear will almost always show things to be different. But that's because generally the differences we can measure with instruments are far smaller than ones we can perceive. So two lines of independent evidence -- from test gear, and from bias-controlled listening -- are the ideal (their results should be in accord).

agreed, but we can change sensitivities to remove some of that from the equation, and we can set accepted deviances in our analysis.

if we are talking about cables though, where nothing else has changed in the equation, then i am willing to lay money that differences will be minuscule at best for the test gear. mainly because i do not believe that cables can change the sound in the audible band.

but i do agree that testing shows us what to listen for, and then we confirm with our ears. the only real difference is that by and large, we can trust test gear.

OK, I wrote my first post, only to find out I have to have two more, for it to ever see the light of day. So, here is a little more of where I am coming from.

About 15 years ago, my brother sent me home with two turntables he didn't really want. He wanted me to pick on of the two, and give the other one back. I realize that it is much easier to distinguish between turntables than CD players, let alone cables, but this story may add an element to blind testing that may not be discussed that much. That would be getting to know the gear really well, prior to the blind test. Anyway, I wanted to pick the best one, so here is what I did.

Oops, I guess my wife NEEDS to get on the computer, so I will call this my second post and continue this later.

Blind testing does not preclude "getting to know" equipment, and abx testing allows the user to listen to the piece for as long as he or she wishes. Just two things you might consider in your posts.

Buy another PC or assert your authority!