Transparent vs Shunyata

[LL21]

Wow! Thank you! Very interesting!!

 

[GuillaumeB]

Wow! Thank you! Very interesting!!

+1 brilliant post

Guillaume

 

[audio.bill]

A square wave tests signal integrity in both the frequency and time domain, and only up to the test frequency. Ie. a 12k Hz square wave will require all frequencies up to and including 12k Hz to be both equal in magnitude and arrive at the same time.

I respectfully believe the statement above that square waves only require signal integrity of frequencies up to and including the test frequency is factually incorrect. A square wave is mathematically equivalent to the sum of a sine wave at that same frequency, plus an infinite series of odd-multiple frequency sine waves of diminishing amplitudes. That is what makes its reproduction such a demanding test, since accurate recreation requires signal integrity of a bandwidth that far exceeds that of the test signal's frequency.

 

[Speedskater]

Hopefully the 'signal integrity of frequencies up to and including the test frequency' is a typo.
But anyway a 12 kHz square wave, when examined through an audio frequency bandpass filter is the same a a 12 kHz sine wave.
The only things that are at extremely high frequencies (I'll let you pick that number) are noise, interference and oscillation.

 

[MadFloyd]

The basics of TA are that their cables are designed to roll off the frequencies above the audible range. In order to do this, the single most important factor for them to know is the output impedance of whatever equipment they are connecting to. And just like speaker crossover complexity, the steeper you want that roll-off to be, the more complex the network must be.

TA seem to roll off well below the audible upper limit - do you suppose that is because a slope is needed? They also roll off deep bass too, is the same thing going on in the lower frequencies?

 

[still-one]

TA seem to roll off well below the audible upper limit - do you suppose that is because a slope is needed? They also roll off deep bass too, is the same thing going on in the lower frequencies?

I disagree that Transparent cables roll off the deep bass frequencies.

 

[MadFloyd]

I disagree that Transparent cables roll off the deep bass frequencies.

Let me try to qualify that statement then: To my ears and in my system, the TA Reference XL seris (speaker cables and interconnects) do not produce as much deep bass as MIT or Shunyata cables that I have auditioned. The difference was not subtle.

 

[Champ04]

I respectfully believe the statement above that square waves only require signal integrity of frequencies up to and including the test frequency is factually incorrect. A square wave is mathematically equivalent to the sum of a sine wave at that same frequency, plus an infinite series of odd-multiple frequency sine waves of diminishing amplitudes. That is what makes its reproduction such a demanding test, since accurate recreation requires signal integrity of a bandwidth that far exceeds that of the test signal's frequency.

Hopefully the 'signal integrity of frequencies up to and including the test frequency' is a typo.
But anyway a 12 kHz square wave, when examined through an audio frequency bandpass filter is the same a a 12 kHz sine wave.
The only things that are at extremely high frequencies (I'll let you pick that number) are noise, interference and oscillation.

Yes. Though the concept of a square wave is only an ideal anyway, as no system can actually reproduce one perfectly, since neither rise time nor fall time time is ever 0, etc.
I apologize for the confusion. Was mixing elements in my head, thinking more of the practicalities of speaker response to square waves and what not. An original intent was to point out that the number of speakers that can reproduce a square wave can be counted (almost) on one hand. And even they can be separated into how high in frequency of square wave can be reproduced. So whats the point of a cable that can? But that part got left out.
Anyway, the point was not the specific frequency. It was the combination of amplitude and time.

TA seem to roll off well below the audible upper limit - do you suppose that is because a slope is needed? They also roll off deep bass too, is the same thing going on in the lower frequencies?

I've seen nothing to suggest that TA intentionally rolls off bass. And as far as rolling off at the upper limit before the limits of audibility, well, a lot of that depends on matching the output impedance of the electronics with the network. Perhaps not an ideal match? I don't know.
My feeling is that it is inevitable that ANY network parts (regardless of being in parallel) will absorb signal energy. (Nothing works "ideally".) I would expect that this would result, not so much in the rolling off of deep bass, but softening it by virtue of that energy lost in the network. But that's just a guess.
I think the idea that TA has, eliminating noise above the audible frequency range by using a low pass filter, is a clever one. I just think it falls under the category of trying to scratch your left ear with your right hand. Yes, it's possible and it works to some extent. But is it ideal or even advisable?

 

[CGabriel]

Square waves and why we care about them

A square wave test is a very commonly used test for amplifiers. It indicates how fast an amplifier can respond to a change in the signal - sometimes referred to by the listener as transient speed. A square wave test is not a pass/fail test. One cannot simply say that component-X can pass a square wave. Component-X may be able to pass a 1Khz square wave with little visible distortion while at 10Khz the leading and falling edge of the square wave may be visibly rounded.

How to interpret a square wave test:
Look at the vertical rising and falling lines of the square wave. Are they 90 degrees to the horizontal portion of the waveform. Is there a slant so the vertical line. At the top and bottom of the waveform - look for a rounding of the vertical as it approaches the horizontal line. A rounded waveform on the rising vertical edge and the falling vertical edge indicate that high-frequency energy is either being rejected or absorbed by the component.

To properly interpret a square wave response you would want to know the frequency and the duty cycle of the test signal. You cannot compare a 1Khz square wave to a 10Khz square wave. You also need to know the settings of the oscilloscope when the test was taken. Changing the time-base of the scope will dramatically affect the appearance of the waveform. All the settings should be identical for a valid comparison.

I have seem some claims about cable square wave response where the diagram looks like it was drawn and there is no information given about signal specifications.

Why Shunyata Research uses a square wave test:
We use the square wave test to demonstrate the technical superiority of the ?TRON technology. We publish the screen captures from the oscilloscope and we have a video on our website that demonstrates the actual test. This test has also been demonstrated at several trade shows to live audiences where the members can come up and examine the cables and the test equipment.

This test demonstrates that ?TRON technology can actually improve bandwidth and square wave response compared to the exact same cable without the technology. This technology actually improves the response time to the signal by the wire itself. If you are interested in the technical aspects you can refer to the patent application:

https://www.google.com/patents/US20120080212?dq=caelin+gabriel&hl=en&sa=X&ei=vgvxU5K_E9HvoASwn4CgAw&ved=0CEYQ6AEwBg