Elsdon Wonfor Audio LS-25 speaker cables

[ryder]

What i found was that almost all other cables, deviated from the reference, more so than even a standard zip cord. This suggested to me that the more complex the design, the more it deviated from the ideal. From that i concluded that zip cord would be more appropriate for most situations and that a lot of manufacturers do not address the areas of concern. Many of them claim to address skin effect errors but measurements show to be no better than standard and often was significantly worse.

LS-25 was of exception however, in which i could not reliably tell the difference between this and my reference. The engineering also agreed with my understanding of transmission line theory. So i merely keep it for physcological satisfaction. However i would still be happy with a standard cable if my hand was forced. I have always felt though that the high frequency does roll off a touch, which the LS-25 appears to fill in. Though i do admit i could be imagining this.

There is no argument on my part however that there are differences to be heard, its just that the differences are almost always worse.

May I ask what is your "reference". Thanks.

 

[DANOFDANGER]

May I ask what is your "reference". Thanks.

With audio cables, home testing is difficult. One cannot reliably compare cables and conclude which is technically superior. For myself i developed a high quality, engineered, application specific reference. This was costly and time consuming. It cost me $2 and under 10 minutes.
This was a standard zip cord cable cut to under 10cm. This provides a reference to use to compare other cables and show how close to transparency it is.

 

[ryder]

Missed that part. Why is it cut to under 10cm. I thought it should be speaker cable?

 

[DANOFDANGER]

I go over the reasoning here

 

[ryder]

My comparisons are not the typical cable vs cable which i believe is inferior and counterproductive. I always directly connect my amplifier to the speakers for an effectively no cable connection.
This provides an ideal reference to analyze the data and more reliably associate what differences are better or worse.

Danny.

Ahh right. Got it. That's the ideal case, though in most (or all cases) that's not possible in domestic applications as the cables would usually be in the 3m to 5m range, or more.

 

[ryder]

Perhaps compare your reference in the form or 4m pair to the LS25?

 

[DANOFDANGER]

Ahh right. Got it. That's the ideal case, though in most (or all cases) that's not possible as the cables would be usually in the 3m to 5m range, or more.

Thats right, its only a reference tool. If it were practical enough, then we would never have cable threads. But because of its qualitys as a reference, we can find that compromise with longer lengths. Which so far is 14 gauge zip cord or LS-25.

Perhaps compare your reference in the form or 4m pairs to the LS25?

I have compared longer lengths of zip cord, further down that page i linked is my comparison review.

 

[drummerman]

Good Litz wire is not cheap. That goes some way to account for cost. What material is the jacket? Also, is there some filtering before termination?

 

[Julf]

This has a significant impact on the results from blind test research. Unless you decide not to use random trial subjects, i fear results will always be inconclusive.

Are you familiar with ITU BS.1116?

 

[Julf]

The issue however i believe, is with time domain distortion. We can definitely measure it, we can definitely show differences.

Are you talking about the effects of cable inductance and capacitance, or something else? I would love to see some typical measurements...

 

[DANOFDANGER]

Are you familiar with ITU BS.1116?

No i will have a look at it.

Are you talking about the effects of cable inductance and capacitance, or something else? I would love to see some typical measurements...

Yes i am talking about reactance and its direct effect on phase shift. There are not a lot of measurements around showing phase shift of speaker cables, the ones few available do show that phase is non linear accross the audio band. Although current data suggests we should not hear it, i do propose that we underestimate the time domain sensitivity of human hearing.
There are plenty of standard electrical measurements of speaker cables, showing their reactive characteristics. They are typically all unique, with slightly varying inductive reactance between them. Now both capacitve and inductive reactance has an effect on phase. But i would assume its mostly inductive here.

However i do not think that simple inductance on its own is the problem, as i found concerning contradictions. Maybe if i had more data i could say for sure, but with kimber kable. Measurements show that inductance is fairly identicle between their 8PR, 4PR and 8TC. But when i had these in my possesion, there were differences. I do wonder if phase shift is directly proportional to impedance, or whether there is some other variable. Internal and external proximity effect come to mind.

 

[DANOFDANGER]

Are you familiar with ITU BS.1116?

If i am not mistaken, these look like parameters for audio trial systems. Has this been applied in anything significant? It seems to detail the rules for subject selection to rule out the variablility of a listeners capability. Interesting. Its very thorough, if applied i would have to seriously consider its results.

 

[Julf]

If i am not mistaken, these look like parameters for audio trial systems. Has this been applied in anything significant? It seems to detail the rules for subject selection to rule out the variablility of a listeners capability. Interesting. Its very thorough, if applied i would have to seriously consider its results.

It is the standard procedure for ITU/EBU to evaluate digital systems and codecs (especially lossy ones), so yes, it has been applied a fair bit when determining broadcast system standards.

 

[Julf]

Yes i am talking about reactance and its direct effect on phase shift. There are not a lot of measurements around showing phase shift of speaker cables, the ones few available do show that phase is non linear accross the audio band. Although current data suggests we should not hear it, i do propose that we underestimate the time domain sensitivity of human hearing.

On the other hand, the speakers and crossovers cause much more significant phase shifts.

 

[DANOFDANGER]

On the other hand, the speakers and crossovers cause much more significant phase shifts.

Yes i have seen you mention this before, but is it not realistic to assume that phase errors in crossovers is detrimental as well. This could be one of the major factors that separate speakers. Crossovers are of major concern in speaker technology, i would think that time domain errors are taken into consideration as well as frequency domain.

It is the standard procedure for ITU/EBU to evaluate digital systems and codecs (especially lossy ones), so yes, it has been applied a fair bit when determining broadcast system standards.

It would be very interesting if this was applied in other fields as well.

 

[Julf]

Yes i have seen you mention this before, but is it not realistic to assume that phase errors in crossovers is detrimental as well.

Not realistic to assume, but realistic to take into account. The crossover is not the only source of phase errors in loudspeakers. Have you ever measured the phase behavior of a loudspeaker? Here is a typical one:

It would be very interesting if this was applied in other fields as well.

It is. Broadcasting standards is just the area where it is actually mandated.

 

[DANOFDANGER]

Not realistic to assume, but realistic to take into account. The crossover is not the only source of phase errors in loudspeakers. Have you ever measured the phase behavior of a loudspeaker? Here is a typical one:

Yes of course, a speakers transducer is effectively an inductor and so it contributes to the phase deviation. The one you posted is a little less complex than im used to seing. Looks like a two way ported speaker.

Other measurements as far as i have seen make out the phase shift to be far more volatile. But i would think this has an impact on audio fidelity. I must read more into this.

One thing i have not tackled much is speaker acoustics, i have read vance dickinsons loudspeaker book. But i have pushed more of my time on signal processing, might need to move on now.

It is. Broadcasting standards is just the area where it is actually mandated.

Any relative studies with audio electronics, such as speaker cables, power amplifiers, digital to analog converters ?.

 

[Julf]

The one you posted is a little less complex than im used to seing. Looks like a two way ported speaker.

Indeed.

One thing i have not tackled much is speaker acoustics, i have read vance dickinsons loudspeaker book. But i have pushed more of my time on signal processing, might need to move on now.

I definitely recommend the Floyd E Toole book I linked to in the separate thread.

Any relative studies with audio electronics, such as speaker cables, power amplifiers, digital to analog converters ?.

I do know several of the research facilities (such as National Research Council of Canada) use the same methodologies.

 

[DANOFDANGER]

I definitely recommend the Floyd E Toole book I linked to in the separate thread.

Iv had that downloaded ready to go after you made the thread
I have seen toole used as a reference for current understanding and research on acoustics. So should be good read.

 

[CJ14]

Good Litz wire is not cheap. That goes some way to account for cost. What material is the jacket? Also, is there some filtering before termination?

No deliberate filtering at all, but due to construction the capacitance & inductance do act like a filter, on test the cable at 1Metre has a self resonance into no load of 1MHz and a roll of 10MHz @ 0.5db into 8 Ohm.
Sorry my writing skills are crap so I hope this helps.