By impedance matching the HF energy on the cable is lost into the load.

What value do you assume for the load impedance?
A ribbon cable will have a fixed impedance/frequency profile, whereas the speaker impedance/frequency profile is dynamic. How then do you match impedances?

 

What value do you assume for the load impedance?
A ribbon cable will have a fixed impedance/frequency profile, whereas the speaker impedance/frequency profile is dynamic. How then do you match impedances?

Easy load, 5.2 ohm. Resistive. Wide bandwidth. Direct connection from amp to driver (system is triamplified), no caps or inductors.

 

 

I did too. The CAT5 is about half the impedance of twin lead. Still way too high a match for the load. Very little difference on the scope @ 100 kHz.

How can one cable be "superior" then if at the speaker terminals the signal is identical using either cable?

 

Easy load, 5.2 ohm. Resistive.

That may well be a rated or DC impedance, but a speaker's actual impedance isn't purely resistive and isn't constant, as shown in the figure in Ron's post above! Your cable may be ok for impedance matching to a 5.2 Ohm resistor, but you won't get much sound out of that .

 

That may well be a rated or DC impedance, but a speaker's actual impedance isn't purely resistive and isn't constant, as shown in the figure in Ron's post above! Your cable may be ok for impedance matching to a 5.2 Ohm resistor, but you won't get much sound out of that .

These are not coil speakers. They are ribbon planar speakers. The resistance is ruler flat through the spectrum.

 

Resistance is the same of course, but not impedance. Think about it.. It's a coil. A coil has inductance so Z=2 pie F*L +R.
At audio frequencies and the low source impedance of the amp, the only thing your wire can influence is resistance. So if you like really loud music use thick cable.

 

How can one cable be "superior" then if at the speaker terminals the signal is identical using either cable?

You cited two cables, twin lead and CAT5. I replied to your examples only. We both hooked up both, those two being similar. This thread is about trace pair ribbons. The scope photos clearly show considerable differences at the speaker terminals between this family of cables and the ribbon construction.

Superiority is a non-issue. Minimal signal alteration is the issue.

 

Resistance is the same of course, but not impedance. Think about it.. It's a coil. A coil has inductance so Z=2 pie F*L +R.
At audio frequencies and the low source impedance of the amp, the only thing your wire can influence is resistance. So if you like really loud music use thick cable.

My mistake. I meant impedance. These are magneto-planar, no coils. Although being more like a straight wire, I'm sure there is some self inductance somewhere.

 

Don't they usually have an impedance matching transformer?

 

True. Also valid with most (99%+) audio systems. Then there are the snake oil audio vendors out there, very frustrating. The audio boards are very bad. By impedance matching the HF energy on the cable is lost into the load. This minimizes repeated reflected waves which gradually erode audio frequency transients. It works. I understand your algebra point, but if after measuring Cp, Ls and DC, the math (for example velocity) should be in the ballpark and generally agree. That's all. I discovered my ur resultant to be too low I think. It took months to iron out other problems, this ur remains. What is a reasonable value for these diamagnetic materials? Just under 1? Thanks for any input.
Pete

wtf does THAT mean.

iron erodes under the action of oxygen.
stone erodes under the action of wind and rain
how the #%& does one erode an 'audio frequency transient' ? (why with repeated reflected waves of course)

I smell a sales pitch disguised as a question. Wrong place to try that gag bub.

 

Don't they usually have an impedance matching transformer?

Don't they usually have an impedance matching transformer?

Not at 5.2 ohms.

 

Why not?
I guess you will have to tell us which one you spent your life savings on.

 

Want to know what's funnier than an audiophile?

A guitarist. $100 "tone" cables, $50 vintage "tone" capacitors, "True Bypass" pedals, lacquer finishes, etc. It's simply baffling the myths some of my brethren believe.

 

Although being more like a straight wire, I'm sure there is some self inductance somewhere.

Indeed there is. A straight wire has inductance. Hence its reactive impedance will change with frequency. The planar conductor of the speaker also has parasitic capacitance, which will vary with the distance of the conductor from the magnet and again change the impedance.

 

Here's a sim you might find informative/convincing/amusing....
It models a 5 Ohm ribbon speaker when driven by a 1V amplitude 25kHz signal (deemed the maximum of interest in the real world) from a 0.5 Ohm source, via ~10 metres of (1) 'normal' cable with a 100 Ohm characteristic impedance and (2) ribbon cable with a 5 Ohm characteristic impedance. The transmission line model in each case is lossless.
As can be seen from the FFT plots, the 'normal' cable plot has a secondary peak at ~3MHZ, some 55dB below the main peak.
The ribbon cable FFT plot secondary peak is at ~2.5MHz, some 60dB below the main peak.
Arguably, the ribbon cable introduces slightly less distortion (obviously the trumpeted selling point ), but this is entirely academic because the 25kHz signal, and certainly any signal in the MHz region, is completely inaudible regardless of its level.

 

...but this is entirely academic because the 25kHz signal, and certainly any signal in the MHz region, is completely inaudible regardless of its level.
View attachment 80046

You are completely missing the point of this amplifier/cable/speaker system. Since there are no capacitors or other reactive elements, there is nothing to attenuate (filter) the ultrasonic to Rf signals which will cause oscillations in the speakers and lead to undesirable audible harmonics that are nearly as noticable as the sub-sonic oscillations caused when the neighbor's dog begins to wag his tail as he sees his owner return home.

If you check eBay and Amazon, I have a new product that covers windows to dampen sub-sonic-neighbor's-dog-tail-wagging oscillations in high-end listening rooms. I am working on a supersize version that can cover an entire exterior side of a house and should be available soon. This should be much better than the DIY tactic that many audiophiles are currently using - simply holding their heads up their own asses.

 

You are completely missing the point

LOL. There's a point to it?

 

Here's a sim you might find informative/convincing/amusing....
It models a 5 Ohm ribbon speaker when driven by a 1V amplitude 25kHz signal (deemed the maximum of interest in the real world) from a 0.5 Ohm source, via ~10 metres of (1) 'normal' cable with a 100 Ohm characteristic impedance and (2) ribbon cable with a 5 Ohm characteristic impedance. The transmission line model in each case is lossless.
As can be seen from the FFT plots, the 'normal' cable plot has a secondary peak at ~3MHZ, some 55dB below the main peak.
The ribbon cable FFT plot secondary peak is at ~2.5MHz, some 60dB below the main peak.
Arguably, the ribbon cable introduces slightly less distortion (obviously the trumpeted selling point ), but this is entirely academic because the 25kHz signal, and certainly any signal in the MHz region, is completely inaudible regardless of its level.
View attachment 80046

Thank you. I would like to try my hand at that program. Which sim program is that?

BTW I am not selling these. It is my hobby.
In my defense, I understand the views toward audiophiles, which I also share.
Perhaps if anyone is in the SW Virginia area, stop by and take a listen, if you love music.

 

Which sim program is that?

LTspice (a free download from Linear Technology). Additional spice model libraries are free from the Yahoo LTspice User Group.