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Cables: Measuring the differences

post #1 of 97
Thread Starter 

OK, here we go, the cable comparison, with measurement to back it up.

 

First, my subjective impressions. The silver cables are a smidge brighter/more forward sounding, cleaner, and have better controlled bass. Rhythm and pacing seem more right with the silver cables. The silver cables are more revealing as well. Overall, I prefer the silver cables to the stock cables for most listening.

 

I used REW to run the tests, and measured my HD650's using a SHURE WL93. I did not compensate for the mics FR so these images are for comparison purposes only and do not represent the true FR of the headphones.

 

Mic Setup:

I hung the headphones, placed the mic inside the ear piece by clipping it to a wire that slid up under the ear pad, then clipped the mic cable to the head band to ensure that any movement of the cable above the headphone would not push or pull on the mic rig. I also did a control measurement after conducting my two tests per cable to ensure that the stock cable still measured the same, and it did as shown in the mic control graph.

 

The volume chosen was a loud but still listenable volume.

 

The first graph compares the stock and silver cables unsmoothed:

 

stock_vs_silver_raw.png

 

The silver cables are dark green. There are clear differences here even with the unsmoothed data.

 

--

 

Here is a second comparison smoothed:

 

stock_vs_silver_smooth.png

 

The silver cables are dark blue here. It's easy to see the differences between the two in the upper mids/lower treble.

 

--

 

Mic Position Control Graph:

I measured the stock twice, then silver twice, then just to make sure the mic wasn't bumped in switching cables I created this control of the stock cables when I was finished:

 

StockRefCompare.png

 

The ref is in red compared to the stock trace from the test just above.

 

--

 

Here is a GD graph, (the sine waves are displayed on an axis):

 

stock_vs_silver_GD.png

 

What this tells me, and correct me if I'm wrong, is that the test tones are better controlled with the silver cables in dark green. The fringe of the dark green looks more even.

 

--

 

Last, here is a comparison of two sine waves around 300hz. The stock cable appears more jagged and the silver cables reproduce the sine wave more precisely:

stock_vs_silver_sineShape.png

 

The important thing to note is that while the absolute frequency response is basically the same here, the tone and control of bass is going to be better with the silver cables.

 

 

I hope that what I have shown here is that cables can affect the sound of a system. The important thing about this test is that the comparisons were done at listenable (still loud by my standards) volumes, further testing at higher volumes (deafening) indicates that the curves start to merge together as volume goes up. This is important to note for future testing. Objectively the approach to measuring and testing audio should be from a human perspective and not performance absolutes.

 

 


Edited by cheapskateaudio - 11/2/11 at 11:43pm
post #2 of 97

Well, this is certainly interesting - never seen measurements like this before.  It would be nice, however, to see tests done with more professional test equipment, as one positive test isn't enough to wave around as "proof," but this is certainly does suggest a very audible difference between stock and silver cables.

 

What sort of a setup did you use to test this, by the way?  Do you have any pictures of the rig?

 

Also - I think, to confirm this, someone else should do a similar test with the same gear but different testing equipment to see if it turns out the same.


Edited by DaBomb77766 - 11/1/11 at 12:54am
post #3 of 97
Thread Starter 


 

Quote:
Originally Posted by DaBomb77766 View Post

Well, this is certainly interesting - never seen measurements like this before.  It would be nice, however, to see tests done with more professional test equipment, as one positive test isn't enough to wave around as "proof," but this is certainly does suggest a very audible difference between stock and silver cables.

 

What sort of a setup did you use to test this, by the way?  Do you have any pictures of the rig?

 

Also - I think, to confirm this, someone else should do a similar test with the same gear but different testing equipment to see if it turns out the same.

 

How is this not proof of a difference? Look at the graph showing the StockREF and the first stock trace, they line up near perfect from about 200 hz up... That is a clear demonstration of the repeatability of the results. 

 

 

post #4 of 97
Quote:
Originally Posted by cheapskateaudio View Post


 

 

How is this not proof of a difference? Look at the graph showing the StockREF and the first stock trace, they line up near perfect from about 200 hz up... That is a clear demonstration of the repeatability of the results. 

 

 



This is the first time a measurement like this has ever been shown to be positive, from my understanding.  As such, I reserve a right to be skeptical - not to say that your measurements are faulty, but if this is in fact a positive result, it would be pretty much a big deal, to say the least.  The graphs do indeed look pretty conclusive, but again, as with any test like this, more measurements by third parties will be needed to come to a true conclusion.

 

Still though, it appears you have done an excellent job with your measurements, and I see little reason to doubt them, other than the fact that nothing like this has ever been demonstrated before.

post #5 of 97

Well done!! Apprecaite your effort to have your own intepretation and test to prove your point. Salute.

 

Subscribe and waiting for hot debate here lol... It would be interesting if you do this with silver coated copper, copper and stranded ... etc etc. New myth buster?


Edited by OneSec - 11/1/11 at 1:19am
post #6 of 97

Hi, as DaBomb says, this is an important result. You should not be worried by scrutiny. The best person to do this - in the first instance - is you. The favored approach in science is not to try to "prove" a hypothesis (in this case, that there's a difference between cables), but to try to disprove it. In other words, think of as many things as possible that might have interfered with your results. For everything you think of, what did you do or what can you do to discount ("control for") these possible interferences.

 

You already reported some you controlled for (e.g. testing whether the mic might have got bumped; measuring each cable twice in at least one instance; etc). Are there others? For example, changes in environmental sound during measuring, which might have been different for each cable? Anything else in the chain of steps you might accidentally have done differently? Any instability in your test equipment? That sort of thing.

 

It would be great if you could describe everything possible about your equipment and procedure to make it easier for others to duplicate. DaBomb is right about this too. For reasons connected with measurement error (equipment; procedure etc) and statistical sampling, no result in science is accepted based on one study, no matter how carefully done. It has to be repeated by others, both exactly ("direct replication") and with variations ("systematic replication") that help evaluate the relative importance of different factors and ultimately contribute to theory building and further theory testing.

 

BTW, I'm not trying to disprove your result. I'm just describing part of what I have to do in my own scientific work and in my part-time consulting work (I help medical researchers at a near-by hospital design their studies - or I review their designs when they've already done them - and advise them on effective statistical approaches and/or perform their analyses).

 

post #7 of 97

Really well done for a start. It would be nice to see different groups all in agreement, especially a group of non cable believers in agreement here. At higher volume maybe the results change due to signal distortion within the equipment. There really is so many variables still in this simple test and I wonder why this has never been shown in such a test? A test has been done in this same way many times before but maybe here there is a special clue that will lead to more information about cable signal changing properties.

 

If things are really the way I understand them around here, you should get numerous questions from folks who are interested in duplicating the events shown. What is truly an amazing discovery comes simply from seeing in graph form what cable character sound changes you hear. If this in turn ends up being true it would be a big deal so say the least. It would be very interesting if the same results could be graphed for many cables, as seeing the characteristics in graph form would open a whole new door in cable choosing. It would be interesting if the same cable sound from different cables could be seen in a graph as the same.

 

The question that I figure will be asked is if the graphs are still showing a result which can not be heard and that there were not enough cables tested to overcome the possibility of the graphs showing a result which just by luck seems to verify what you heard.


Edited by Redcarmoose - 11/1/11 at 5:54am
post #8 of 97

WAHAHAHA BEAUTIFUL!

 

I might ship my Blue Dragon / Silver Dragon to you if it's alright. It's time to prove a point. But like the DG graph explains (if I'm not mistaken.) It's really the control of the sine waves that a cable improves. Very similar to improving frame-rate in a videogame. 20-25 is nowhere near as enjoyable as 60-100. Case made! After that the nuances and intonations a very improved! And Silver just changes everything!

 

And also I find interesting... This was with a diy cable! I wonder the differences 'pro' cables might make. I might ship my cables to you just for kicks. We could even get the usb indirectly measured~! FANTASTIC!

 

Ohhhhhh measuring a recables Grado too... Lol. I have both stock cable and Blue Dragon direct soldered to the same Grado soldering just to tell the difference / enjoy a different sound every once in a while!

 

 

Very good job!


Edited by Hennyo - 11/1/11 at 8:56am
post #9 of 97

 

What's the resistance, inductance and capacitance of each of the two cables you used for comparison?

 

Also, why was this posted here, rather than Sound Science?

 

se

 

 

post #10 of 97

Great job and very interesting! It looks like there is a ~3 dB difference at 2k, odd. It should be reproducible by others though. Hopefully someone else will be able to measure some differences, otherwise it doesn't mean much. 

post #11 of 97
Thread Starter 

I did more tests today and differences continue to show across the frequency range. Surprisingly, I have not been able to duplicate the *exact* differences after moving the mic. The only thing that is predictable is that the cables *are* different, tend to be more different in certain frequency ranges, and that through multiple rounds of a single test one cable will have a very consistent curve and the other cable will have another consistent curve. 

 

So, obviously moving the mic modifies the measured response of the headphones. The thing to note is that moving the mic also modifies the measured differences. This would indicate that the cables change the dispersal pattern of the driver. If the cables do change the dispersal pattern, the only truly accurate way to measure the sound differences would be in some kind of echo chamber resembling the human ear canal.

 

In lieu of an echo chamber, the next step is to measure the dispersal pattern of the driver by positioning the mic in different areas and running the above series of tests for each position. Then, maybe it would pertinent to average the curves for each cable and compare the average? 

 

Anyone know how frequencies tend to disperse on the face of a driver? Do lows come off the edges more and highs from the center? 

 

post #12 of 97
Thread Starter 
Quote:
Originally Posted by Steve Eddy View Post

 

What's the resistance, inductance and capacitance of each of the two cables you used for comparison?

 

Also, why was this posted here, rather than Sound Science?

 

se

 

 


I'll have to get a MM to measure that.

 

I guess it could have gone in the science section. Feel free to move it if you want.

 

post #13 of 97

Interesting results. I'll be curious to see more - especially as you refine the experiment with better controls... 

 

It would also be interesting to see if there are differences between cables of the same conductor (e.g. inexpensive copper cables, vs. high-end copper cables) etc. 

post #14 of 97
Quote:
Originally Posted by cheapskateaudio View Post


 

 

How is this not proof of a difference? Look at the graph showing the StockREF and the first stock trace, they line up near perfect from about 200 hz up... That is a clear demonstration of the repeatability of the results. 

 

 


It is evidence of a difference, but like other forms of testing, it needs to be repeated and verified before we can really call it proof.

 

I am not up on iterpreting the graphs, so are the differences you have shown in a known audible range? I ask because so often cable makers show differences to 'prove' their point, but all they have done is show a difference between something inaudible and something else that is also inaudible.

 

post #15 of 97

Can we see various tests of the same cable layered on top of one another? Test the same cable five times in a row for example. Take it in and out every time, as if you were switching.

 

More graphs of both cables would help too.

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