Do Measurements Matter? Designers Speak Out.

[warpie]

I guess many of you have already read this but I just found it and I think it's quite interesting.

 

[sahib]

Comments from some credible personalities but I have not heard of TEF-20 test set and I am not sure about measuring the harmonic distortion in cables (if there is any). But if it was published in AES then perhaps the masters can comment on this.

The test equipment used for such test has to have a THD content lower than the wire can produce. and I don't think that TEF-20 is one of them. I don't even know if such test set is available off-the-shelf.

To be able to measure that sort of phenomena in conductors requires to go down to nitrogen level temperature and even then it is still not  easy to do.

And at that level you hear nothing. So why bother.

 

[JohnRoberts]

Comments from some credible personalities

I think that's a different Linkwitz ( than linkwitz-riley), but may be the same Thiel (as thiel-small)

but I have not heard of TEF-20 test set

I think TEF is early energy vs time test equipment...looking at signals wrt time allowed for measurements without anechoic chambers. where you can see and ignore early reflections from boundaries, or whatever. 

and I am not sure about measuring the harmonic distortion in cables (if there is any). But if it was published in AES then perhaps the masters can comment on this.

I am familiar with Jon Risch's paper on multi-tone IMD, (AFAIK he is still working at Peavey) I think I read that paper before he submitted it. I don't recall it having anything to do with cables, but basically it's an improved multiple tone IMD test where the tones are selected so modulation products do not interfere constructively or cancel. Jon is a rare golden ear with an engineering degree.  8)

I think that guy who mentioned Jon's paper is probably trying to sell wire using that as the hook. 

The test equipment used for such test has to have a THD content lower than the wire can produce. and I don't think that TEF-20 is one of them. I don't even know if such test set is available off-the-shelf.

To measure distortion in wire, context is important. Wire begins as very low impedance so for nonlinearities in that low impedance to matter, it need to be loaded by a low impedance and working hard... This is kind of like the whole capacitor boondogle. If the cap is just loafing along, it is not likely to express many non-linearities (a gross oversimplification on my part).

To be able to measure that sort of phenomena in conductors requires to go down to nitrogen level temperature and even then it is still not  easy to do.

And at that level you hear nothing. So why bother.

Searching for distortion in wire seems like pretty much a fool's mission.

I had many great discussions with Jon. Short of outright arguments, but we often differed by degree of some phenomenon's significance. I helped him use a more expensive (film) capacitor in a crossover design when his boss declined to approve the engineering change over several cents of added cost. It wasn't even my product or department. but my signature was good enough to get it done, and it was a no-brainer for me (passive crossover caps are doing heavy lifting so need to be decent). 

JR 

 

[sahib]

Thank you for the clarification John.  I have not really read the whole thing to the end. After those three bullet points I just scanned it quickly. It was obvious that the author of the article was trying to bring some credibility but still falling short.

 

[1954U1]

Yep,
the site owner is a cable seller.

Usual gems in product sections..

It is the dramatic silencing of the cables themselves and the completely unimaginable improvement in depth and clarity of sound that was the real reward.

But, as always, the winner IMO is an USB cable:

Cardas Clear USB is a musically neutral cable and sounds the same at any usable length, between all components.

 

[Andy Peters]

I guess many of you have already read this but I just found it and I think it's quite interesting.

Well, that was a waste of the thirty seconds I spent reading the article.

-a

 

[thermionic]

But, as always, the winner IMO is an USB cable:

Cardas Clear USB is a musically neutral cable and sounds the same at any usable length, between all components.

Crikey. Those kind of claims simply shouldn't be allowed by law. I get asked on a regular basis by friends and associates as to whether such cables will give an 'improvement'. It's not because they're audiophiles, it's because they're non-technical people and are looking for a solution to a separate problem, the origins of which they are unable to fathom. Marketing BS such as that quoted above can trick non-technical folk into parting with their cash, in the hope it'll provide some kind of solution. It's wrong.

J

 

[Speedskater]

It's the same Siegfried Linkwitz, now at:
http://www.linkwitzlab.com/

The TEF-20 is an older model,  Time Energy Frequency room acoustics analyzer.

The newer unit.

TEF25  USB Preamplifier
A Powerful New Tool For Acoustical Analysis
http://www.gold-line.com/tef/t-tefpre.htm

 

[buildafriend]

I stopped reading that article after I started to feel like it was glorifying manufacturers being very dishonest about their specs.

 

[JohnRoberts]

It's the same Siegfried Linkwitz, now at:
http://www.linkwitzlab.com/

The TEF-20 is an older model,  Time Energy Frequency room acoustics analyzer.

The newer unit.

TEF25  USB Preamplifier
A Powerful New Tool For Acoustical Analysis
http://www.gold-line.com/tef/t-tefpre.htm

My bad. I had a senior moment and confused Linkwitz with Lipshitz, whom I'd met at AES show years ago.

L-R crossover was notable achievement.

Still unsure about that article, (name dropping for effect?).

JR

 

[Speedskater]

I get the names confused all the time too.

But I think that SL was writing about loudspeakers.  That measurement measure differences, they don't decide preferences. With loudspeakers in rooms, there can be no perfect correct answer.  So a human has to decide which errors are important and which are less so.