Scott,
It wasn’t a double blind test nor did both types of wire have the same gauge. The twists were similar but not identical and both variables (conductor and insulation) were changed at the same time. Both conductor materials were solid core. This comparison fell far short of being scientific however the scale of the difference was such that it didn’t need to be. Repeated comparisons were carried out as I don’t trust first impressions but the results were similar every time.
Thylantyr said golden ears never carry out properly controlled ABX double blind tests. Golden ears – I don’t know about that but I am sure ABX tests have their uses, but I can reliably determine whether the music I am listening to is at A=440Hz or at A=444Hz pitch without reference to anything, so at least in this respect I have a reliable ‘memory’ - just for the record. Whether this is relevant is another matter though.
Tim.
It wasn’t a double blind test nor did both types of wire have the same gauge. The twists were similar but not identical and both variables (conductor and insulation) were changed at the same time. Both conductor materials were solid core. This comparison fell far short of being scientific however the scale of the difference was such that it didn’t need to be. Repeated comparisons were carried out as I don’t trust first impressions but the results were similar every time.
Thylantyr said golden ears never carry out properly controlled ABX double blind tests. Golden ears – I don’t know about that but I am sure ABX tests have their uses, but I can reliably determine whether the music I am listening to is at A=440Hz or at A=444Hz pitch without reference to anything, so at least in this respect I have a reliable ‘memory’ - just for the record. Whether this is relevant is another matter though.
Tim.
Oh yes, there are people around with absolute hearing that will tell you the difference between music played in 440 or 444. But they won't tell you the difference between pvc and ptfe in and abx test. Those are 2 very different tests.
Having measured cat5 cable for more than 4 years as a job, I can tell you that under 1MHz they are no better than zip wire. the impedance is all over the place. and those Hf rejection things are going down from from 30MHz and up. So at audio...
Measured as in making sure there's 100m in each box ?
Yust kidding.
That the impedance varies as much as zip-wire doesnt mean they are no good for audio.
And theres still alot of crap below 30mhz that you dont want on your cables.
Yust out of curiosity, what were all the parameters you had to check on the cat's?
Regards,
Coolin
Yust kidding.
That the impedance varies as much as zip-wire doesnt mean they are no good for audio.
And theres still alot of crap below 30mhz that you dont want on your cables.
Yust out of curiosity, what were all the parameters you had to check on the cat's?
Regards,
Coolin
Sanity check.
For example, Belden a manufacturer of cable/wire sells 'plenum'
versions of their cables {telfon}, not because teflon sounds better,
rather because;
http://www.webopedia.com/TERM/P/plenum_cable.html
What is Plenum Cable ?
Cable that is run in the plenum spaces of buildings. In building construction, the plenum (pronounced PLEH-nuhm) is the space that is used for air circulation in heating and air conditioning systems, typically between the structural ceiling and the suspended ceiling or under a raised floor. The plenum space is typically used to house the communication cables for the buildings computer and telephone network(s). However, use of plenum areas for cable storage poses a serious hazard in the event of a fire as once the fire reaches the plenum space there are few barriers to contain the smoke and flames. Plenum cable is coated with a fire-retardant coating (usually Teflon) so that in case of a fire it does not give off toxic gasses and smoke as it burns. Twisted-pair and coaxial versions of cable are made in plenum versions.
For example, Belden a manufacturer of cable/wire sells 'plenum'
versions of their cables {telfon}, not because teflon sounds better,
rather because;
http://www.webopedia.com/TERM/P/plenum_cable.html
What is Plenum Cable ?
Cable that is run in the plenum spaces of buildings. In building construction, the plenum (pronounced PLEH-nuhm) is the space that is used for air circulation in heating and air conditioning systems, typically between the structural ceiling and the suspended ceiling or under a raised floor. The plenum space is typically used to house the communication cables for the buildings computer and telephone network(s). However, use of plenum areas for cable storage poses a serious hazard in the event of a fire as once the fire reaches the plenum space there are few barriers to contain the smoke and flames. Plenum cable is coated with a fire-retardant coating (usually Teflon) so that in case of a fire it does not give off toxic gasses and smoke as it burns. Twisted-pair and coaxial versions of cable are made in plenum versions.
TimA said:
I wish I could. Still, I see no reason to doubt that you can -several of my friends are professional musicians / opera singers with hyper-acute accuracy in both listening and especially, performing, though this is a staggeringly small difference well outside the most sensitive region of our hearing, especially if they are not steady-state tones, but within a musical structure. (I take it that it was throw out as a general example though, and not to be taken quite literally) Then again, a cable is not going to change a 440Hz note into a 444Hz note.
As I said in my previous post, I'm sure you did hear some form of minor difference, but now you have confirmed what I suspected: namely that the cables were completely different in proportions (solid-core silver? OUCH! My wallet is trembling!), twist et al, I think I can safely suggest that the minor differences you heard are entirely down to the different properties of resistance, capacitance and inductance of the two cables, not the conductor material, and still less its dilectric.
thylantyr said:
Aha! So that's what the 'no smoke zero Halogen' business means then! You know, I thought it had something to do with having been rubbed on the thighs of large-breasted blonde virgin nymphets after being imersed for 24 hours in triple-refined oil of snake.
The magazine for those of monster wallet and greater gullibility -specifically Hifi+ actually ran a series of blind 'listening tests' on different commercial cables a while back (issue 34), ranging from a set of relatively inexpensive QED types up to the knee-tremblingly expensive Nordost Valhalla. No measurements were taken of course (electrical performance of a cable is clearly irrelevant bacause it carries a musical signal, not electricity)
To be fair to them, although these were not ABX tests, they were at least done blind.
The results were not particularly interesting, showing very little variation / listener preference within the points scoring framework devised for the test, with one exception I'll mention in a minute. A brief glance at the utterly different designs of the cables tested shows that the minor differences (and they undeniably were according to their own method of rating cable performance [spare me!]) that existed can clearly be attributed to the different aforementioned electrical properties of these pieces of wire rather than any mystical nonsense.
What I found more interesting was the fact that in the subsequent write-up and 'analysis' (Ha!) they went to great lengths to stress the invalidity and uselessness of blind testing, because it takes away from the reviewer all his points of reference, and the biggest intagible is, in fact, the listener. Hmm. Odd that. I could have sworn that's what it is supposed to do.
My favourite part of this 'test' for its entertainment value was the final 'table of results' where a cable (Siltech SQ-110 interconect at the bargin price of £1430 1m pair and LS-188 speaker wire for a mere £6300 for 5m pair), recieved an 'adjusted' score, putting it second on the list, on the arbitary basis that it didn't suit the system
Despite claiming that they had proved the invalidity of blind testing, their own very close results from blind-testing actually did the opposite, clearly displaying that human psychology will exagerate minor percieved gains through the roof unless kept firmly in check by a proper scientific test. Sigh.
Best
Scott
I mentioned absolute pitch solely because it may or may not - I don’t know - have an effect on how and what I hear. I can say that the audible differences between the cables were not minor for me, also that I was aware of the slightly altered speaker bass alignment caused by the smaller diameter of the silver wire, this was later compensated for via a small change to the reflex port length. More recently, but listening through ESLs this time, I have compared a twisted stranded copper wire in ptfe with the twisted solid silver in ptfe, both cables were of almost identical cross sectional area and twist. The differences between them were subtle and to my mind fairly insignificant, the silver sounding a tad more focussed.
Tim.
Tim.
Nope, teflon is certainly not halogen-free. Mostly these are jackets are loaded with salts that have a lot of bonded in water. This water gets released at high temperatures, retarding the spread of flames. These jackets do not have the strenght of ordinary jackets.
Of the cable coming in we measured impedance of each pair and crosstalk over the 1-100MHz range between each pair. This was for cable on drum/box.
Impedance is a function of the geometry, so if this one is fixed, it is rather predictable. The impedance is well defined above 10MHz, but below it is rather erratic. Even in the HF region, it goes +/-20% easily. Also, you need enough lenght or good terminations to measure it, 1km is fine.
Crosstalk is also geometry related, so very dependent on stability. If you are going to open the jacket, you ruin it. Just putting on a connector is enough to drop the rejection 10's of dB's.
Of the cable coming in we measured impedance of each pair and crosstalk over the 1-100MHz range between each pair. This was for cable on drum/box.
Impedance is a function of the geometry, so if this one is fixed, it is rather predictable. The impedance is well defined above 10MHz, but below it is rather erratic. Even in the HF region, it goes +/-20% easily. Also, you need enough lenght or good terminations to measure it, 1km is fine.
Crosstalk is also geometry related, so very dependent on stability. If you are going to open the jacket, you ruin it. Just putting on a connector is enough to drop the rejection 10's of dB's.
That's why I advocate a ferrite clamp if RFI pickup is a problem.
I tend to stick to zip cord as a rule now as it's ultimately cheaper and less hassle: the best performing varients of Cat5 speaker leads are a) very bulky -6 runs or a minmum of 4 is required for a reasonable performance in my view, and b) need a considerable amount of time and effort in twisting and braiding, which i would prefer to spend doing other things.
BTW, my use of the phrase 'zero halogen' was purely that of a product name available here at Maplin and elsewhere -RS components for e.g.: http://www.maplin.co.uk/Module.aspx?ModuleNo=19868&doy=5m9D
Cheers
Scott
I tend to stick to zip cord as a rule now as it's ultimately cheaper and less hassle: the best performing varients of Cat5 speaker leads are a) very bulky -6 runs or a minmum of 4 is required for a reasonable performance in my view, and b) need a considerable amount of time and effort in twisting and braiding, which i would prefer to spend doing other things.
BTW, my use of the phrase 'zero halogen' was purely that of a product name available here at Maplin and elsewhere -RS components for e.g.: http://www.maplin.co.uk/Module.aspx?ModuleNo=19868&doy=5m9D
Cheers
Scott
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