[Split]Technical split from: Pear Cable CEO Calls James Randi's $1 Million Offer a Ho

[Paulhoff]

So you have a poorly designed amp and dodo happens.

Paul

 

[Paulhoff]

Did you check out this link? http://sound.westhost.com/cable-z.htm I posted it back on page 6 of this thread.

Apparently instability is a major concern for high end audio equipment. They blame it on high capacitance cables and solve it with zobel networks which add (guess what) more capacitance.

Please there is tons more capacitance in the speaker itself for one thing, and the capacitance in normal wire lowwwwwwwwwwwwwwwwwwww.

Paul

 

[Dan O.]

If you don't want to follow that link, Randi posted one in the Dec 10, 2004 SWIFT.

And despite your opinion of the quality of such an amp, do you admit that it is possible to build an amp that displays such characteristics?

 

[Paulhoff]

If you don't want to follow that link, Randi posted one in the Dec 10, 2004 SWIFT.

And despite your opinion of the quality of such an amp, do you admit that it is possible to build an amp that displays such characteristics?

It is possible to build an amp with many characteristics, like making a solid state amp sound like a tube amp etc. It is not a true quality amp if one has to play games with it.

Paul



Quality is not always equal to money.

 

[Dan O.]

We aren't talking about the quality of the amp. This is only in response to the RAH-E challenge.

The rest of the system (source, amplifier, speakers and listening
room) is at the choice of the test subject, as is the selection of
music, and the duration of the individual trials.

I claimed only that that challenge could be easily won. I also posted how and posted supporting evidence.

 

[krabapple]

Interesting. You can post links without waiting by leaving spaces in them.

Thanks. MIT and Transparent are two of several 'high end' cable makers that employ 'network boxes' on their products (and interestingly, the two used to be partners). These network boxes appear to be passive(?) compenents that alter frequency response. Read about them starting int eh 700's on this AVSforum thread, which is more in-depth (and up to date) than the Usenet threads

www.avsforum.com/ avs-vb/ showthread.php?t=918365

 

[krabapple]

We aren't talking about the quality of the amp. This is only in response to the RAH-E challenge.


I claimed only that that challenge could be easily won. I also posted how and posted supporting evidence.

So, the distortions introduced wouldn't be measurable at the speaker terminals?

 

[Paulhoff]

We aren't talking about the quality of the amp. This is only in response to the RAH-E challenge.


I claimed only that that challenge could be easily won. I also posted how and posted supporting evidence.

That would only be the case if poorly designed equipments was used.

Paul



I may come as a big shock to you, but audio equipment has no need to work in the mhz range.

 

[Dan O.]

So, the distortions introduced wouldn't be measurable at the speaker terminals?

If the distortion is only a differential phase shift between the right and left channels, the cables could measure flat over the entire audio range 20-20k but the difference would be detectable as certain sounds apparent origin shift spatially. Even smaller changed may be necessary to alter the 3D soundscape. (The 3D soundscape we hear is a result of micro-echos from the structure of the outer ear. Since these structures are on the order of 1-2cm, that could correspond to frequencies in excess of 20kHz. I'm still looking for details on this.)

Wether these differences would be visible on an oscilloscope or computer connected to the speaker terminals is uncertain. You would have to filter out the noise from the system including the room echos feeding back into the speakers to make the A/B comparison.

 

[Paulhoff]

If the distortion is only a differential phase shift between the right and left channels, the cables could measure flat over the entire audio range 20-20k but the difference would be detectable as certain sounds apparent origin shift spatially. Even smaller changed may be necessary to alter the 3D soundscape. (The 3D soundscape we hear is a result of micro-echos from the structure of the outer ear. Since these structures are on the order of 1-2cm, that could correspond to frequencies in excess of 20kHz. I'm still looking for details on this.)

Wether these differences would be visible on an oscilloscope or computer connected to the speaker terminals is uncertain. You would have to filter out the noise from the system including the room echos feeding back into the speakers to make the A/B comparison.

Phase shift would be the same for both channels for the same frequency so to the one listening nothing would change for the 3d soundfield.

Paul

 

[Dan O.]

Phase shift would be the same for both channels for the same frequency so to the one listening nothing would change for the 3d soundfield.

Could you post a reference to back that up?

If there is a sound source directly in front of you, the wave form reaching each ear will be identical. If that sound source is raised, the sound waves reaching each ear will still be identical but slightly changed. These changes allow you to perceive the elevation of the source.

 

[Paulhoff]

Could you post a reference to back that up?

If there is a sound source directly in front of you, the wave form reaching each ear will be identical. If that sound source is raised, the sound waves reaching each ear will still be identical but slightly changed. These changes allow you to perceive the elevation of the source.

If one does not know the original sound, how can one know that they have changed?

Paul

 

[Dan O.]

If one does not know the original sound, how can one know that they have changed?

If you hear a bird singing, will you be able to tell if that bird is above you in a tree or below you on the ground? How is this possible if you had not previously heard this bird before?

[gratuitous statement added to keep this post on topic...]
The RAH-E challenge is poorly constructed and I'm sure can be easily beat. If JREF were to accept that protocol for the million I would take take it myself.

 

[Paulhoff]

If you hear a bird singing, will you be able to tell if that bird is above you in a tree or below you on the ground? How is this possible if you had not previously heard this bird before?

That is only because you can move your head, if I lock your head in only one position and it could not be moved, you would not know if it was up in a tree or not.

Paul



Head movement is very important.

 

[Paulhoff]

It is the old horse and water and drink thing, but with water and drink changed to knowledge and think.

• Triboelectric effect
• Movement relative to an electric field
• Movement relative to a magnetic field

It is important to realize that there are two separate energy sources for this vibration.


The first energy source comes from the loudspeakers themselves. As music is played, the vibrations in the air (sound) vibrate “hairs” in your ears (so you hear the sound), as well as everything else in the room. This vibration includes your audio cables. This mechanical vibration, induced by the sound itself, is a major enemy of cable producers. Unfortunately, this problem is rarely talked about, and frequently overlooked.


The second energy source comes from the current running through the audio cables. As mentioned previously, the current will produce a magnetic field. Since all of the wires in our audio systems have current running in opposing directions (+ and – lead, this applies to AC as well) opposing magnetic fields are set up in the conductors. These opposing magnetic fields mechanically push the conductors apart, thus causing mechanical vibration. This is a major design consideration for loudspeaker cables. However, in audio interconnects, the current is so small, that this effect can truly be neglected, so we will not elaborate on this second mechanism for now.

This is the snake-oil Pear Cable sales.

Paul



Makes one want to throw-up.

 

[Steve Eddy]

This is the snake-oil Pear Cable sales.

Well, for what it's worth, while it's arguable whether any of that is something to lose sleep over or whether it's significant enough to produce any actual audible differences, there's nothing technically incorrect in what you quoted.

se

 

[Paulhoff]

Well, for what it's worth, while it's arguable whether any of that is something to lose sleep over or whether it's significant enough to produce any actual audible differences, there's nothing technically incorrect in what you quoted.

se

YES THERE IS, it is way out of context, it is many, many orders of magnitude below the signal coming from the amp to the speakers. IT MEANS ABSOLUTILY NOTHING. They are ripping people off. Next they will be talking about ants walking over your wires and the need for their $1,000 ant traps.

$7,000 plus for wire, BS.

How about the gravity affect from your body on the speaker cables as you walk around the room.

Paul

 

[Steve Eddy]

YES THERE IS, it is way out of context, it is many, many orders of magnitude below the signal coming from the amp to the speakers. IT MEANS ABSOLUTILY NOTHING.

As I said, you can argue whether or not it's significant enough to be audible. And just because something may be orders of magnitude below the signal doesn't necessarily mean it means absolutely nothing.

I mean, dither in digital audio recording and processing systems is also orders of magnitude below full signal levels, but if I'm not mistaken, actual audible differences have been established when it comes to different dithering algorithms.

That's not to say that this is the case in this instance. It's only to say that it hasn't been shown not to be the case any more than it has been shown to be the case. I was simply pointing out that there wasn't anything technically incorrect in what was said. And again, you can argue whether or not it's meaningful.

$7,000 plus for wire, BS.

Don't know what the asking price has to do with anything in particular. What difference would it make if they were $700? Or $70?

se

 

[Paulhoff]

As I said, you can argue whether or not it's significant enough to be audible.

It is not audible, geeeeeeeeeeeeeeeeeeeeee.

Paul

 

[sol invictus]

Well, for what it's worth, while it's arguable whether any of that is something to lose sleep over or whether it's significant enough to produce any actual audible differences, there's nothing technically incorrect in what you quoted.

Yes there is.

As mentioned previously, the current will produce a magnetic field. Since all of the wires in our audio systems have current running in opposing directions (+ and – lead, this applies to AC as well) opposing magnetic fields are set up in the conductors. These opposing magnetic fields mechanically push the conductors apart, thus causing mechanical vibration. This is a major design consideration for loudspeaker cables

This is incorrect. Two wires with opposing currents, connected to a constant current source such as an amplifier, attract, not repel.

This is an elementary mistake (which, in fairness, is made in many places). It comes from a naive application of the Lorentz force law. That the correct answer must be an attractive force is obvious from the fact that when the wires are very close the magnetic field is zero, which means that configuration has lower energy than when they are far apart.