Best speaker cable specs

[Ingenieur]

Music is MORE transient in nature than a power transient
A fault may be 10-20 x SS
Transient 2-3 x that
Subtransient 1.5 x

Music?
25-30 dB or more, 20-30x

 

[CinDyment]

TL reduces to lumped in the limit of line length/wavelength -> 0. Which is absolutely valid at audio. I can use relativity to describe a pitched baseball, but that would be silly- Newton does it just as accurately.

Exactly, so calculating an impedance ignoring the dominant lumped value (Resistance) at 100Hz and 1KHz is flawed as is calculating a reflection using a high frequency asymptotic formula for Zo.

 

[Ingenieur]

IT IS NOT DC. Transient. Do I have to get a definition? .... it is an instantaneous change from 0 to some value that is not 0.

The acknowledged expert in the field drew a simplified circuit and named his book Electrical TRANSIENTS in Power Systems. The author is not the issue. The person reading who does not comprehend the difference between a step function and something that is not a step function is the issue.

Audio is not all transient as your quoted book defines transient. In fact, if we look at digital audio or practical analog audio, anything approaching what most EEs would consider a transient literally cannot exist. Everything is constrained to limited rates of changes which changes the effective characteristic of the wavefront in the cable.

Real speakers are resistive and reactive loads. Real speakers have coil resistance, cross-over resistance, etc. and they are substantial. Whatever model you used for a speaker, just like your model for the cable, is wrong at 100Hz and 1KHz. If you are so sure you are right, then show your work and let the other EEs validate it.

Look at the picture
The source is DC

Word salad

Transient, by an EE
MUSIC

 

[AudiOhm]

With all this math, it looks like a Flat Earth debate...

Ohms

 

[CinDyment]

Music is MORE transient in nature than a power transient
A fault may be 10-20 x SS
Transient 2-3 x that
Subtransient 1.5 x

Music?
25-30 dB or more, 20-30x

The size of the fault is meaningless. How fast it transitions from the low state to the high state is.

 

[Ingenieur]

The size of the fault is meaningless. How fast it transitions from the low state to the high state is.

A power line fault?
1/4 x 1/60 = 4 mSec

A 1000 Hz note, 0.3 mS

 

[CinDyment]

Look at the picture
The source is DC

Word salad

Transient, by an EE
MUSIC

The source may be "DC", but the switch causes an instantaneous voltage change on one end of the cable from 0 to the DC level ..... instantly. That is quite difference from being connected to say an AC generator and the switch closing at the zero crossing ... i.e. audio.

 

[Ingenieur]

Exactly, so calculating an impedance ignoring the dominant lumped value (Resistance) at 100Hz and 1KHz is flawed as is calculating a reflection using a high frequency asymptotic formula for Zo.

It is not the dominant as it relates to speaker L sand amp C.
We do not care about energy converted to work.

 

[CinDyment]

A power line fault?
1/4 x 1/60 = 4 mSec

A 1000 Hz note, 0.3 mS

Huh? 4msec? Mechanical switch closure. The transient is a near instantaneous transition unless the voltages are perfectly matched or the switching happens at a zero crossing.

 

[Ingenieur]

The source may be "DC", but the switch causes an instantaneous voltage change on one end of the cable from 0 to the DC level ..... instantly. That is quite difference from being connected to say an AC generator and the switch closing at the zero crossing ... i.e. audio.

So now it's DC, lol
You said it wasn't instantaneous before?

Quote
looks like an non-ideal transmission line where the input is not a rapid change but frequency constrained voltage change?

 

[CinDyment]

It is not the dominant as it relates to speaker L sand amp C.
We do not care about energy converted to work.

You calculated a Zo for the cable, however, as SIY noted, at audio frequencies, you can just use a bulk model. However, you ignored the dominant bulk element in a cable at audio frequencies, resistance. Your Zo below, 26.3 ohms is wrong and meaningless for an analog audio application.

 

[Ingenieur]

Huh? 4msec? Mechanical switch closure. The transient is a near instantaneous transition unless the voltages are perfectly matched or the switching happens at a zero crossing.

What is 'near instantaneous'
0.004 sec on a 60 Hz grid seems close?

 

[Ingenieur]

You calculated a Zo for the cable, however, as SIY noted, at audio frequencies, you can just use a bulk model. However, you ignored the dominant bulk element in a cable at audio frequencies, resistance. Your Zo below, 26.3 ohms is wrong and meaningless for an analog audio application.

View attachment 198409

Incorrect
It has nothing to do with transient response.

The 28.3 is applicable for this analysis

 

[CinDyment]

So now it's DC, lol
You said it wasn't instantaneous before?

Quote
looks like an non-ideal transmission line where the input is not a rapid change but frequency constrained voltage change?

The UNCONNECTED voltage source is some high voltage, lets call it 10,000. One side of the unconnected transmission line is 0 as is the other before the switch closes (parasitics -- I will take license). When you close the switch, that side that is not grounded goes from 0 to 10,000 instantly. There is no situation in analog audio that remotely operates like that.

 

[Ingenieur]

So now it's DC, lol
You said it wasn't instantaneous before?

Quote
looks like an non-ideal transmission line where the input is not a rapid change but frequency constrained voltage change?

Lol

DC, no 'freq constraint'
Not a rapid change
Now instantaneous but 4 mS is not instantaneous enough.
Lol

 

[Ingenieur]

The UNCONNECTED voltage source is some high voltage, lets call it 10,000. One side of the unconnected transmission line is 0 as is the other before the switch closes (parasitics -- I will take license). When you close the switch, that side that is not grounded goes from 0 to 10,000 instantly. There is no situation in analog audio that remotely operates like that.

What is instantaneous?
No time constant or frequency of oscillation or propagation velocity?

ALL audio operates like that
A 20 kHz will rise to peak in 12 uSec
Faster than ANY power line transient

 

[CinDyment]

Incorrect
It has nothing to do with transient response.

The 28.3 is applicable for this analysis

I get it. You have no idea what characteristic impedance is, what Zo is (at all frequencies), or the difference between what a step function is, and well, not a step function.

The 26.3 is ONLY applicable if there is a step function (or close to it). It would be important if you were using the cable say for SPDIF. For analog audio, no.

 

[Ingenieur]

I get it. You have no idea what characteristic impedance is, what Zo is (at all frequencies), or the difference between what a step function is, and well, not a step function.

The 26.3 is ONLY applicable if there is a step function (or close to it). It would be important if you were using the cable say for SPDIF. For analog audio, no.

No, it applies to ANY reactive power waveform regardless of frequency (within the audio domain)

Only an R is instantaneous

V = L di/dt
I = C dv/dt
Both involve dt, time rate of change
If 0 undefined

 

[monkeyboy]

With regard to the L and C, it's a linear system so the wire can just be represented by a frequency dependent gain and phase shift...both of which are negligible for audio signals, just keep the R ie voltage drop small...

 

[CinDyment]

No, it applies to ANY reactive power waveform regardless of frequency (within the audio domain)

Use it in an equation, a full one, say at 1Khz .....