Why!? Please Tell Me Why!

[Sal1950]

3 minutes ago, mordante said:

 

So basically ever product ever made. Best looking, best tasting, fastest service, prettiest etc. Every subjective claim ever.

Better would be to remove religion and sports from education.

https://en.wikipedia.org/wiki/False_pretenses

[jabbr]

1 hour ago, mansr said:

should be noted that it need not be the source that expends energy.

 

Good point. Shannon’s concept of “information entropy” not physical entropy

[Summit]

On 2018-04-21 at 5:14 PM, gmgraves said:

I didn't say Martin-Logan' s ESL speakers had better dispersion than all speakers, I said they had better dispersion than many speakers and they do. I can sit pretty much off-axis in my listening room and still get a decent stereo image. But my point to Frank was that there are limits...  

 

Martin-Logan's ESL speakers doesn’t have better horizontal dispersion than many other speakers. The dispersion is lower than most other speakers. To have low horizontal and vertical dispersion is normally a good thing and result in less unwanted reflation from the sidewalls and ceiling.

[mav52]

23 hours ago, marce said:

Wrong its between 40-86% of C, depending on the dialectics involved and construction. As an average for signals on PCBs a rough rule of thumb is 150mm/ns (approx half that of C, light in a vacuum).

You have a link

 

[mansr]

5 minutes ago, mav52 said:

You have a link

For what, the speed of electrical signals in metal wires? I don't have a link handy, but it's easy enough to measure it.

[Summit]

15 hours ago, jabbr said:

 

Based on your poor poor understanding of the difference between signal and flow of electricity, my confidence in your ability to define anything is zero. I’m not being pedantic rather factual. 

 

Fine but signal could also be digital 

 

No no no no no no no no.

 

Im not being obtuse, you simply don’t understand. 

 

 

No, this is really basic. Really basic. Read Wikipedia or a textbook. Please. If you can’t understand why the direction of signal transmission is not the same as the direction of current flow, I’m afraid there’s no hope for you to understand electronics. 

 

How  can I state this more clearly?

 

Why are you saying No no no no no no no no. An audio signal is flow of electricity.

[mansr]

3 minutes ago, Summit said:

Why are you saying No no no no no no no no. An audio signal is flow of electricity.

Doesn't have to be. Are you saying the grooves on an LP aren't audio signals?

[Summit]

10 minutes ago, mansr said:

Doesn't have to be. Are you saying the grooves on an LP aren't audio signals?

 

It’s not until the pick-up converts the needles movement’s in the grooves in to a signal.

[mansr]

So smoke signals and semaphores aren't signals either then? You people have some weird definitions of words.

[marce]

17 minutes ago, mav52 said:

You have a link

 

Read my earlier post on Velocity factor...

Search signal velocity factor.

We have to know how fast a signal is travelling down a trace for length matching of high speed traces such as DDR memory interfaces... And to make it more fun signals travel faster on the outer layers of a PCB (microstrip) than they do on inner layers (stripline) as half the signal travels through air on the outer layers. Of course if you mix the core materials of a PCB then it can get really fun...

As said the rough rule of thumb that has been around for years and years is the 6" rule, a signal will travel approx 6" in 1ns on a PCB, you have to understand both electrical length and skew times for high speed analogue and digital, RF, microwave etc. so calculating the correct wavelength for a particular medium is important. and for that you have to know how fast the signal travels.

Vf=1/SQ root or Er.

A basic from Wiki

[marce]

https://en.wikipedia.org/wiki/Velocity_factor

Forgot the link...

[Summit]

21 minutes ago, mansr said:

So smoke signals and semaphores aren't signals either then? You people have some weird definitions of words.

 

Smoke signals is another type of signal, not related to the electrical signal that are transmitted with a speaker cables.  

[Solstice380]

1 hour ago, Sal1950 said:

Not me, but there are laws against embezzlement. 

 

And fraud. ?

[mansr]

30 minutes ago, marce said:

We have to know how fast a signal is travelling down a trace for length matching of high speed traces such as DDR memory interfaces... And to make it more fun signals travel faster on the outer layers of a PCB (microstrip) than they do on inner layers (stripline) as half the signal travels through air on the outer layers. Of course if you mix the core materials of a PCB then it can get really fun...

And sometimes the weave orientation matters. I don't recall seeing any audiophool products make a big deal out of this. Could there be a market opportunity here?

[Solstice380]

Ed Meitner (and maybe 1 or 2 others) use ceramic circuit boards.  

[jabbr]

1 hour ago, Summit said:

 

Why are you saying No no no no no no no no. An audio signal is flow of electricity.

 

An “electrical audio signal” uses current & voltage to represent/convey information — they are not the same.

 

To be specific, a flow is a vector with magnitude and direction. A signal represents a flow of information. The magnitude and direction of a signal is not the same nor in the same units as the magnitude and direction of the electricity used to carry the signal. 

 

An audio signal is not a flow of electricity it uses flows of electricity. 

 

In  the same way that you might use a pen to write a book — the ink is not the book. The book is not strokes of the pen but uses strokes of the pen to convey information.

[pkane2001]

27 minutes ago, Summit said:

 

Smoke signals is another type of signal, not related to the electrical signal that are transmitted with a speaker cables.  

 

Blowing smoke up customer's you-know-what is absolutely a signal related to certain speaker cables

 

[jabbr]

Why is this important in simple terms?

 

1: the signal travels from one box to the other

2: the cable connects one box to the other

3: an arrow on the cable may indicate the direction of signal flow 

4: electrical current does not simply flow from one box to the other

[Summit]

34 minutes ago, jabbr said:

 

An “electrical audio signal” uses current & voltage to represent/convey information — they are not the same.

 

To be specific, a flow is a vector with magnitude and direction. A signal represents a flow of information. The magnitude and direction of a signal is not the same nor in the same units as the magnitude and direction of the electricity used to carry the signal. 

 

An audio signal is not a flow of electricity it uses flows of electricity. 

 

In  the same way that you might use a pen to write a book — the ink is not the book. The book is not strokes of the pen but uses strokes of the pen to convey information.

 

An audio signal is a flow of electricity!!

 

What do you think the audio signal consist of if not a flows of electricity? Why use a bigger amp to drive insensitive speakers if not because they can output more power, current and voltage?

[Summit]

31 minutes ago, pkane2001 said:

 

Blowing smoke up customer's you-know-what is absolutely a signal related to certain speaker cables

 

 

Yes and we have signal and we also have a lot of noise..

[Solstice380]

9 minutes ago, Summit said:

 

Yes and we have signal and we also have a lot of noise..

 

That’s why S/N ratio is so widely, and appropriately, used. 

[jabbr]

28 minutes ago, Summit said:

 

An audio signal is a flow of electricity!!

 

What do you think the audio signal consist of if not a flows of electricity? Why use a bigger amp to drive insensitive speakers if not because they can output more power, current and voltage?

 

would you ever say that at any point in time the audio signal travels from the speaker to the amp?

 

would you ever say that at any point in time the audio signal travels from the amp to the DAC?

 

Answer yes or no.

[marce]

1 hour ago, mansr said:

And sometimes the weave orientation matters. I don't recall seeing any audiophool products make a big deal out of this. Could there be a market opportunity here?

LOL

Lets hope they never get hold of a document that shows the different weaves such as this:

https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature/an/an528.pdf

Though I have seen some use of more exotic materials in some audio products. But for most stuff up to approx 2GHz FR4 will suffice, though the higher the frequency the better quality FR4's are recommended. Just for general interest below shows the layer stack set up for a reasonably high speed design (ALL diff pairs, high speed analogue), it from a test board for wave front sensor. The same set up is required for any computer based design, with high speed interfaces, such as PC's, streamers etc. Again it goes back to signal integrity, length matching etc. Differential pairs (LVDS) are critical, keeping the signals coupled and in phase is critical to reduce common mode noise, if the signal cross zero at different times you get some CM noise on the ground plane. These details and others are more critical to the design than using fancy audiophile components on an audiophile streamer (or any high speed design) and whether the main supply is linear. It all helps keep the main source of digital noise down, simultaneous switching noise.

 

 

Forgot to say, in the background the Er, loss tangent and resistivity of the materials used for construction of the PCB are stored in a data base, for use by the 3D field solver for simulation, timing and skew parameters.

[Summit]

19 minutes ago, jabbr said:

 

would you ever say that at any point in time the audio signal travels from the speaker to the amp?

 

would you ever say that at any point in time the audio signal travels from the amp to the DAC?

 

Answer yes or no.

 

Not the audio signal. Back-EMF (Electro-Motive Force) yes. A speaker is sending back a lot of electricity because speakers work by pulling and pushing. But it’s not the audio signal it sending back to the amp it is this opposing power.

[marce]

1 hour ago, Solstice380 said:

Ed Meitner (and maybe 1 or 2 others) use ceramic circuit boards.  

I believe Mr N Pass has also used different materials. There are many types available, the problem with the ceramic based materials is manufacturing costs, they are harder to process and keep to the required tolerances. There are many factors to consider, thermal can be an issue in some high powered audio devices so the use of a better substrate, whilst not strictly necessary for signal fidelity can have benefits. Again there are high Tg FR4's available, but they like the BT laminates cost more than standard FR4's.

This is an interesting tome on laminates, the IPC also has a lot or relevant material such as IPC-4101E... The biggest stir up in the laminate world was the introduction of lead free soldering, the standard 130 deg Tg laminates were problematic at the higher re-flow temperatures so they had to improve the products, for most designs DIY or Commercial a good FR4 with a 170 Deg Tg is a good bet, not to expensive but better than the generic stuff you will get if you don't specify your required laminates.