[malldian]

How many of you would be interested in purchasing a DIY switchbox that could be used to conduct your own testing of cables without having to actually switch them yourself? Could a DIYer make these at a reasonable price? If I were into cables right now, I would certainly be interested..

 

[Lapwing]

Quote:

Originally Posted by malldian /img/forum/go_quote.gif How many of you would be interested in purchasing a DIY switchbox that could be used to conduct your own testing of cables without having to actually switch them yourself? Could a DIYer make these at a reasonable price? If I were into cables right now, I would certainly be interested..

The problem is the pro-cable loonies would claim the quality of the switch is the bottleneck and not their precious cables. A much better method for testing cables would be to simply attach a ammeter in series between source and destination and monitor the current over a time period.

 

[nick_charles]

Quote:

Originally Posted by Lapwing /img/forum/go_quote.gif The problem is the pro-cable loonies would claim the quality of the switch is the bottleneck and not their precious cables. A much better method for testing cables would be to simply attach a ammeter in series between source and destination and monitor the current over a time period.

Um, if the objectivist camp wants to maintain credibility or even some kind of scientific high ground then labelling those with differing world views as loonies is not the way to go about it, I humbly suggest...

In fact it is trivial to find measurable differences between cables, a change in cable gauge will lead to certain changes in resistance and a big enough difference will lead to audible signal loss, Monster do this in their demos - whether this signal loss is accompanied by a fundamental audible change in the FR is tougher to determine. However signal loss is signal loss and to compensate requires increasing gain and thus noise whether the extra noise is audible is of course open to question.

Even Pear can show that their cables have less high freq roll-off than generic speaker cable, but is this audible ? only proper listening tests would determine this.

 

[Lapwing]

Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif Um, if the objectivist camp wants to maintain credibility or even some kind of scientific high ground then labelling those with differing world views as loonies is not the way to go about it, I humbly suggest... In fact it is trivial to find measurable differences between cables, a change in cable gauge will lead to certain changes in resistance and a big enough difference will lead to audible signal loss, Monster do this in their demos - whether this signal loss is accompanied by a fundamental audible change in the FR is tougher to determine. However signal loss is signal loss and to compensate requires increasing gain and thus noise whether the extra noise is audible is of course open to question. Even Pear can show that their cables have less high freq roll-off than generic speaker cable, but is this audible ? only proper listening tests would determine this.

If it's not detectable via objective scientific instruments I will not believe it. I do not trust my ears nor anyone else's.
It wouldn't even be that hard to conduct such an experiment and I'd be completely shocked if it hasnt been done before. I want to see data which shows definitively that high quality cable allows for a significantly cleaner, more linearly flat frequency spectrum for signal transfer. We're talking about cables which are only a couple of meters long! come on!...

 

[nick_charles]

Quote:

Originally Posted by Lapwing /img/forum/go_quote.gif If it's not detectable via objective scientific instruments I will not believe it. I do not trust my ears nor anyone else's. It wouldn't even be that hard to conduct such an experiment and I'd be completely shocked if it hasnt been done before. I want to see data which shows definitively that high quality cable allows for a significantly cleaner, more linearly flat frequency spectrum for signal transfer. We're talking about cables which are only a couple of meters long! come on!...

I think you have misinterpreted some of my post. Differences between cables have been measured in terms of inductance, resistance and capacitance. Cardas have done this so have Pear. Pear boast improbably large differences and do not cite their comparator cables while Cardas show differences that are much more realistic and are in the small fractions of an ohm range - for instance in their comparison the signal loss over 10ft for their cable is 0.0033v while the comparator drops 0.007v from a 1V starting signal.

For a better tech comparisopn see

Speaker Cable Faceoff 2 - Measurements Part 1 — Reviews and News from Audioholics

You raise a valid point when you introduce the word significantly. A 0.0037v difference may well be statistically significant but it may not be detectable and as long as the difference is constant across the audible spectrum utterly unimportant.

One confounding factor neeeds to be introduced. It is possible to nobble the high end response deliberately, this would certainly give rise to audible differences , possibly pleasing ones but would it still represent high fidelity ?

 

[malldian]

Personally I am interested in what I hear in a blind test. I want to see two cables that look the same but, for example, have copper in one and silver in the other (all else equal) and be able to see if I can hear a difference at a push of a button. Maybe this belongs in the DIY forum but I feel like something like this would be used at meets a lot.

 

[upstateguy]

Quote:

Originally Posted by malldian /img/forum/go_quote.gif How many of you would be interested in purchasing a DIY switchbox that could be used to conduct your own testing of cables without having to actually switch them yourself? Could a DIYer make these at a reasonable price? If I were into cables right now, I would certainly be interested..

We certainly could use a high quality ABX box for use at meets.... it shouldn't be so hard to build or cost very much.

USG

 

[Lapwing]

Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif I think you have misinterpreted some of my post. Differences between cables have been measured in terms of inductance, resistance and capacitance. Cardas have done this so have Pear. Pear boast improbably large differences and do not cite their comparator cables while Cardas show differences that are much more realistic and are in the small fractions of an ohm range - for instance in their comparison the signal loss over 10ft for their cable is 0.0033v while the comparator drops 0.007v from a 1V starting signal. For a better tech comparisopn see Speaker Cable Faceoff 2 - Measurements Part 1 — Reviews and News from Audioholics You raise a valid point when you introduce the word significantly. A 0.0037v difference may well be statistically significant but it may not be detectable and as long as the difference is constant across the audible spectrum utterly unimportant. One confounding factor neeeds to be introduced. It is possible to nobble the high end response deliberately, this would certainly give rise to audible differences , possibly pleasing ones but would it still represent high fidelity ?

I fail to see how voltage drop as a result of the resistivity of cable material would cause sound quality degradation. The real question at hand is whether changing the cable material can affect different frequencies at varying degrees, in which case the cable would color the sound.

The article you linked does exactly this, and the graphs at the bottom of that page are very revealing. Particularly the resistance vs. frequency graph: Notice how nearly linear every cable is compared to each other up until a critical point around 20khz, above this it trivial since the human ear cannot hear. This is important, a flat linear plot of this graph indicates an uncolored audio. With the slight exception of one cable (the River Cable which diverges sooner around 10khz) all of the models fit relatively very well against each other. The only significant difference I see is a linear change in conductance, this was to be expected of course since some of these cables are made from materials with varying resistivity levels. So, sure there are some cables which more efficiently transfer the signal, but this does not mean that the sound is colored, or will sound any different to the human ear at equalized volume levels.

 

[wnmnkh]

Btw I am currently making switch/distribution box for some tests...

 

[Lapwing]

Quote:

Originally Posted by wnmnkh /img/forum/go_quote.gif Btw I am currently making switch/distribution box for some tests...

That was your six hundred and sixty sixth post! You must be up to no good!

 

[wnmnkh]

Hahahahaha.... such a post in science forum.....

 

[nick_charles]

Quote:

Originally Posted by Lapwing /img/forum/go_quote.gif So, sure there are some cables which more efficiently transfer the signal, but this does not mean that the sound is colored, or will sound any different to the human ear at equalized volume levels.

If you look at the Pear product info this is exactly what they claim for their Anjou series speaker cable - they show a graph (albeit rather laughable) suggesting that the high frequency loss from 10K onwards on their cable is far less than on an unnamed "leading competitor".

Sadly although they had the opportunity to empirically test this against a suitable competitor in a $1m challenge they opted to pull out, thus we will never know...

 

[stewtheking]

I have a switch box of sorts. I made it as an input selector, for when I had a speaker amp with only one input.

The box, and bits, cost me less than $40, and it wouldn't be all that much more money to make a slightly different design (of slightly higher quality components) which would be designed to act as an ABX test box.

You'd probably want the box to sit connected between the source and amplifier, with both sets of cables connected to it at both ends, and a toggle switch, so the signal was only going through one pair at a time. For this, all you'd need was an enclosure, a suitable switch, 4 pairs of RCA sockets, and some hook-up wire (suitably high quality of course, so that it's integrity was not called into too much question ).

You could also do it cannibalising an RCA lead, and having two short "pigtail" sections, that went towards amp and source, so that the distance of "non-test" cable was kept as short as possible...

 

[Edwood]

I built a headphone amp switch box so I can A/B compare amps. Tricky part is making sure you feed the same signal to both amps. Just make sure you match everything. So that way the nay sayers can nay all they want, but you are at least "degrading" the signal equally in both instances. With ABX, that is trickier, as the control is not "degraded" so to speak.

-Ed

 

[Lapwing]

Edwood is right... The hardest part of this experiment will be equalizing the current across the different cables. We know for a fact that every cable has a different resistivity (especially when you compare silver to copper) and thus if you run power through both of them using the same amp with the same gain setting they will of course have varying amounts of current.

You can get around this a couple of ways. First you'll definitely need a high quality oscilloscope (which can be quite costly itself), and two identical amplifiers.

Send a clean sine wave through cable-A and then record a reference amplitude level using the oscilloscope to measure the average current and a set point on the gain control. Then swap cable-A for cable-B and conduct the same procedure, recording a new set point on the gain control at the exact same reference amplitude. You can then use two identical amplifiers, one with the gain setting for cable-A, the other with the gain setting for cable-B. Connect Cable-A and Cable-B to a common (highest quality possible) switch.