[mike1127]

I have a new idea for testing the audibility of premium cables.

I have a personal theory that a key factor of quality is a system's impulse response, and more specifically its ability to present musical meaning by clarifying patterns of transients. And it's possible that the most important property of a cable is its effect on transients.

So I had the idea to use a test signal rather than music. I want to use an impulse train.

Yes! Me! Using signals instead of music!

Okay, here's the idea. I create two versions of a test signal. One of them is an impulse train with the impulses occurring ever 50 ms. The second is a modification of this. It's modified by moving some of the impulses slightly in time. For example, it might become

<impulse> (47 ms delay) <impulse> (53 ms delay) <impulse> .... pattern repeated

That is, every other impulse comes 3 ms earlier.

What's neat about this test is that I can write software that creates a series of signals A or B, without telling me. Then I can listen and try to guess each one, and compare it to a file that the software saved with the right answers.

So far I've tried this experiment with a shift of 4 ms, and a shift of 3ms. I burn a CD and play it through my good CD player and cables. With 4ms I get almost every trial right. With 3ms I usually get about 7/8 right. What I want to do is find the smallest shift that is audible with the good cables. Then see if it's still audible with the cheap cables.

Initially I can do this test without any help---I'll know which cables are hooked up. Note that the identity of each test signal, A or B, is unknown to me while I am listening. So that part of it is blind. However, later I can do it "blind" both to the identity of the cable and the specific test signal.

If I tend to do much better identifying A/B with the good cables, that's good evidence. Now, analyzing this mathematically to determine the confidence level is going to be a little tricky. It's no longer a simple, standard function.

 

[Steve Eddy]

Instead of going through all of that, why not just look to see if any of the cables shift the impulses in the first place?

k

 

[mike1127]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif Instead of going through all of that, why not just look to see if any of the cables shift the impulses in the first place? k

The test is about what I can hear. Are you talking about measuring the cables?

 

[Steve Eddy]

Quote:

Originally Posted by mike1127 /img/forum/go_quote.gif The test is about what I can hear. Are you talking about measuring the cables?

It looked to me like what you were wanting to do was determine the cable's effects on transients.

k

 

[71877]

Signals could work, at least its easier for the subject (the brain will interpret it as sound and not as music with all the reactions that come with it). Problem ofcourse is that you're stepping away from a 'real life' situation and people will claim that any result would probably be different with music. I doubt that. What you're doing here is finding both the treshold of both the component and human (what is the smallest difference you can hear on the tested component?).
You dont even have to go ABX in theory, just find the limits on the tested component, do it for as well for the other and compare.

You can seperatly test the human as well.

Another 'problem' is that you have to test with other signals as wel. How big the problem is, depends on how many different signals you find is enough to properly test the human and component.

 

[mike1127]

Quote:

Originally Posted by Koyaan I. Sqatsi /img/forum/go_quote.gif It looked to me like what you were wanting to do was determine the cable's effects on transients. k

I want to determine its audible effect, if any, on a signal made from several impulses (repeating). I won't be able to say how it affects the transients, only that it does (assuming I demonstrate some significant difference).