More 'Audiophile' bullsh*t

More 'Audiophile' bullsh*t

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Discussion

Crackie

6,386 posts

241 months

Monday 20th October 2014
quotequote all
probedb said:
jmorgan said:
Don't you have to balance the way the cable is with respect up and down? Doesn't like long treks up and they speed up going down.
This is true and God help you if you put any sharp kinks in the cable, the electrons have a huge crash if they're going too fast into the corner and that ruins the sound.
The electrons are more prone to crash if there is an inductor before the kink because they become very dizzy having just been whizzing round in circles at the speed of light.

TonyRPH

Original Poster:

12,963 posts

167 months

Monday 20th October 2014
quotequote all
Mr2Mike said:
Zobel networks are used with speakers purely to make the speakers impedance more constant over the frequency range to improve stability, as seen by the amplifier. The impedance of a typical figure of 8 speaker cable is not going to change appreciably over the audio frequency range, certainly orders of magnitude less than the drivers and crossover networks, so a Zobel network isn't used to correct cable effects.


Edited by Mr2Mike on Monday 20th October 12:14
Yes, I'm aware of the purpose of a Zobel network.

However, in his book, Bob suggests using Zobel networks on interconnects too. I'll dig out the relevant text and post it later / tomorrow.


TonyRPH

Original Poster:

12,963 posts

167 months

Tuesday 21st October 2014
quotequote all
Mr2Mike said:
TonyRPH said:
I assume you're referring to my post about Bob Cordell's book. (the thread rolled over to the next page for me).

He explains how cables can act as an antenna, and how the effects of this can be minimised using a "Zobel" network at the speaker end (most amplifiers have a Zobel network on the output too).

He also illustrates a model of an average cable, showing all the predicted parameters and so on. Very techie.

It all makes sense (to me at least) in terms of how speaker cables can affect the sound.

It's a science. smile

I hope I haven't opened another can of worms in the great cable debate now.
Zobel networks are used with speakers purely to make the speakers impedance more constant over the frequency range to improve stability, as seen by the amplifier. The impedance of a typical figure of 8 speaker cable is not going to change appreciably over the audio frequency range, certainly orders of magnitude less than the drivers and crossover networks, so a Zobel network isn't used to correct cable effects.


Edited by Mr2Mike on Monday 20th October 12:14
To quote from the book:

BobCordell said:
EMI Ingress from the amplifier input

It is important to recognise that the interconnect cable is an unterminated transmission line. As such, it can exhibit unusual behaviour at frequencies that are related to it's quarter-wave frequency. As with the speaker cable, the quarter-wave frequency for a 10-foot length of interconnect cable will be about 18MHz. A transmission line that is terminated in its characteristic impedance at only one end will usually be quite benign in terms of this kind of behaviour. For this reason it is wise to terminate the interconnect cable at approximately its characteristic impedance Zo at high frequencies with a Zobel network at the amplifier input. Most interconnect cables will have a characteristic impedance Zo between 50 ohms and 100 ohms so a 75 ohm termination at high frequencies is a good compromise. The network should begin to look resistive at least one octave below the quarter-wave frequency, here 18MHz. A Zobel network consisting of a 75 Ohm resistor and a 220pF capacitor will satisfy this requirement.

98elise

26,376 posts

160 months

Wednesday 22nd October 2014
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TonyRPH said:
I should just add that I am aware of certain cables being manufactured as 'directional' - due to the placement of passive components in the cable, particularly those with LC / RC / RLC networks at one end (usually the speaker end).

I think the cables from MIT (amongst others) fit this criteria.

Apart from that, wire is wire, surely!
How can cable that carries a wave be directional? The electrons flow equally in both directions.

TonyRPH

Original Poster:

12,963 posts

167 months

Wednesday 22nd October 2014
quotequote all
98elise said:
TonyRPH said:
I should just add that I am aware of certain cables being manufactured as 'directional' - due to the placement of passive components in the cable, particularly those with LC / RC / RLC networks at one end (usually the speaker end).

I think the cables from MIT (amongst others) fit this criteria.

Apart from that, wire is wire, surely!
How can cable that carries a wave be directional? The electrons flow equally in both directions.
It's 'directional'* in the sense that there is a filter placed at one end of the cable. (You'll note I put 'directional')

  • 'directional' according to the manufacturer. I suppose it's not inconceivable that with some amplifier / speaker combinations, these cables could influence the sound, but the primary reason (as I understand it) is that passive RC/LC networks are placed in speaker cable to minimise EMI ingress, and that the thinking is that placement of said networks at the speaker side provides optimal resistance to EMI ingress - hence the cable being 'directional'.
Theoretically however, the cable should sound the same no matter which way round it's placed.

  • RC/LC network in this case being a derivative of a Zobel network as I highlighted in my post above this one.





Edited by TonyRPH on Wednesday 22 October 07:53

probedb

824 posts

218 months

Wednesday 22nd October 2014
quotequote all
TonyRPH said:
Theoretically however, the cable should sound the same no matter which way round it's placed.
Of course, otherwise please show some repeatable blind testing that shows that this isn't true.

Also can you provide some examples of these cables that have these networks in please. I mean pictures of them opened up to show what's inside. My Straightwire cable has direction arrows on it but it's meaningless, it's a normal cable, I've opened it up.

TonyRPH

Original Poster:

12,963 posts

167 months

Wednesday 22nd October 2014
quotequote all
probedb said:
TonyRPH said:
Theoretically however, the cable should sound the same no matter which way round it's placed.
Of course, otherwise please show some repeatable blind testing that shows that this isn't true.

Also can you provide some examples of these cables that have these networks in please. I mean pictures of them opened up to show what's inside. My Straightwire cable has direction arrows on it but it's meaningless, it's a normal cable, I've opened it up.
From this very thread (posted January 2013)

Cables dissected

Another example

A couple of pics.





I can't provide any blind test proof - but with a poorly designed amp that suffers badly from EMI - it's not inconceivable that these cables would actually make it sound better.

Crackie

6,386 posts

241 months

Wednesday 22nd October 2014
quotequote all
TonyRPH said:
probedb said:
TonyRPH said:
Theoretically however, the cable should sound the same no matter which way round it's placed.
Of course, otherwise please show some repeatable blind testing that shows that this isn't true.

Also can you provide some examples of these cables that have these networks in please. I mean pictures of them opened up to show what's inside. My Straightwire cable has direction arrows on it but it's meaningless, it's a normal cable, I've opened it up.
From this very thread (posted January 2013)

Cables dissected

Another example

A couple of pics.





I can't provide any blind test proof - but with a poorly designed amp that suffers badly from EMI - it's not inconceivable that these cables would actually make it sound better.
it's not inconceivable that these cables could actually make it sound worse too.

TonyRPH

Original Poster:

12,963 posts

167 months

Wednesday 22nd October 2014
quotequote all
Crackie said:
it's not inconceivable that these cables could actually make it sound worse too.
Completely agree with sentiment!!!!


TheExcession

11,669 posts

249 months

Wednesday 22nd October 2014
quotequote all
TonyRPH said:
Crackie said:
it's not inconceivable that these cables could actually make it sound worse too.
Completely agree with sentiment!!!!
Surely that's not how some of these cables get sold, you know demo time, plug in the most expensive at £1K, claim they're the cheap £20 ones, sounds st, plug in the middling expensive ones at £500 - get a sale! hehe

Crackie

6,386 posts

241 months

Thursday 23rd October 2014
quotequote all
TheExcession said:
TonyRPH said:
Crackie said:
it's not inconceivable that these cables could actually make it sound worse too.
Completely agree with sentiment!!!!
Surely that's not how some of these cables get sold, you know demo time, plug in the most expensive at £1K, claim they're the cheap £20 ones, sounds st, plug in the middling expensive ones at £500 - get a sale! hehe
Confirmation bias will be hard at work for people who believe ( or don't believe ) that expensive cables work. The believer is very likely to perceive what they consider to be a genuine improvement in sound quality because that is what they expect and want to hear.

When you factor in http://en.wikipedia.org/wiki/Post-purchase_rationa... then the believer/buyer's opinion is much more likely to be positive.

Evidence, from competently conducted tests, shows that unbiased listeners who have not had their perception corrupted by the two factors above cannot hear the differences between competently designed and constructed cables. It is possible that there are cables out there that can be identified when used in some systems but imho these do not fit into the competently designed and constructed category.



Edited by Crackie on Thursday 23 October 13:41

CoffeeTreat

28 posts

118 months

Thursday 23rd October 2014
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My head hurts reading some of this mainly because I used to understand it (at least in theory at Uni smile.

The cable is part of the load characteristics and will have resistance, inductance and capacitance properties.
The whole circuit from amp through to speak will include this as part of the whole circuit.
If there are passive components on the cable then the end they are placed changes the overall circuit.
Changes to that can make things better or worse to the ear.
Bi wiring, Bi Amping and so on also change the character because they change the circuit
Companies like NAIM and Linn used to (not sure if they still do) have options to have the cross over filter before the power amps and so removed it from the speakers (if I remember correctly). Again changes to the circuit design and presumably easier to to build a high quality cross over in the low voltage and current signal than it is in a speaker.

Any change means a change in the circuit (and critically its frequency response and things like group delay whatever that was but I remember studying it). I think that's the theory? Now turning a cable around, unless it changes one of the magical electrical properties should make no difference.

But then I also agree that the psychological effect of a dent in your credit card does will you into thinking it does sound better.

Apologies if I've just stated the bleedin obvious, I just get the feeling to some a cable does nothing because its just a bit of wire.

Crackie

6,386 posts

241 months

Thursday 23rd October 2014
quotequote all
CoffeeTreat said:
I just get the feeling to some a cable does nothing because its just a bit of wire.
The Dunlavy quotation here http://www.pistonheads.com/gassing/topic.asp?h=1&a... might be of interest.


Riff Raff

5,086 posts

194 months

Thursday 23rd October 2014
quotequote all
Crackie said:
CoffeeTreat said:
I just get the feeling to some a cable does nothing because its just a bit of wire.
The Dunlavy quotation here http://www.pistonheads.com/gassing/topic.asp?h=1&a... might be of interest.
It might be, if your link didn't point to a thread that's dozens of pages long. How about an Executive Summary?

TonyRPH

Original Poster:

12,963 posts

167 months

Thursday 23rd October 2014
quotequote all
Riff Raff said:
Crackie said:
CoffeeTreat said:
I just get the feeling to some a cable does nothing because its just a bit of wire.
The Dunlavy quotation here http://www.pistonheads.com/gassing/topic.asp?h=1&a... might be of interest.
It might be, if your link didn't point to a thread that's dozens of pages long. How about an Executive Summary?
Here you go:

Crackie said:
My apologies for the length of this post but it may be helpful to hear the views of an acknowledged expert; hopefully it might also help improve some posters' understanding of the subject.

The late and very great John Dunlavy ( Google him if you've not heard of him or don't know about the credentials he modestly refers to ) was moved to write the following letter about the subject of cables, cable manufacturers and the sometimes fraudulent claims used to market them.

"Having read some of the recent comments on several of the Internet audio groups, concerning audible differences between interconnect and loudspeaker cables, I could not resist adding some thoughts about the subject as a concerned engineer possessing credible credentials.

To begin, several companies design and manufacture loudspeaker and interconnect cables which they proudly claim possess optimized electrical properties for the audiophile applications intended. However, accurate measurements of several popularly selling cables reveal significant differences that call into question the technical goals of their designer. These differences also question the capability of the companies to perform accurate measurements of important cable performance properties. For example, any company not possessing a precision C-L-R bridge, a Vector Impedance Meter, a Network Analyzer, a precision waveform and impulse generator, wideband precision oscilloscopes, etc., probably needs to purchase them if they are truly serious about designing audio cables that provide premium performance.

The measurable properties of loudspeaker cables that are important to their performance include characteristic impedance (series inductance and parallel capacitance per unit length), loss resistance (including additional resistance due to skin-effect losses versus frequency), dielectric losses versus frequency (loss tangent, etc.), velocity-of-propagation factor, overall loss versus frequency into different impedance loads, etc.

Measurable properties of interconnect cables include all of the above, with the addition of those properties of the dielectric material that contribute to microphonic noise in the presence of ambient vibration, noise, etc. (in combination with a D.C. off-set created by a pre-amp output circuit, etc.).

While competent cable manufacturers should be aware of these measurements and the need to make them during the design of their cables, the raw truth is that most do not! Proof of this can be found in the absurd buzzard-salve, snake-oil and meaningless advertising claims found in almost all magazine ads and product literature for audiophile cables. Perhaps worse, very few of the expensive, high-tech appearing cables we have measured appear to have been designed in accordance with the well-known laws and principles taught by proper physics and engineering disciplines. (Where are the costly Government Consumer Protection people who are supposed to protect innocent members of the public by identifying and policing questionable performance claims, misleading specifications, etc.?) --- Caveat Emptor!

For example, claiming that copper wire is directional, that slow-moving electrons create distortion as they haphazardly carry the signal along a wire, that cables store and release energy as signals propagate along them, that a final energy component (improperly labeled as Joules) is the measure of the tonality of cables, ad nauseum, are but a few of the non-entities used in advertisements to describe cable performance.

Another pet peeve of mine is the concept of a special configuration included with a loudspeaker cable which is advertised as being able to terminate the cable in a matter intended to deliver more accurate tonality, better imaging, lower noise, etc. The real truth is that this special configuration contains nothing more than a simple, inexpensive network intended to prevent poorly-designed amplifiers, with a too-high slew-rate (obtained at the expense of instability caused by too much inverse-feedback) from oscillating when connected to a loudspeaker through a low-loss, low-impedance cable. When this box appears at the loudspeaker-end of a cable, it seldom contains nothing more than a Zobel network, which is usually a series resistor-capacitor network, connector in parallel with the wires of the cable. If it is at the amplifier-end of the cable, it is probably either a parallel resistor-inductor network, connected in series with the cable conductors (or a simple cylindrical ferrite sleeve covering both conductors). But the proper place for such a network, if it is needed to insure amplifier stability and prevent high-frequency oscillations, is within the amplifier - not along the loudspeaker cable. Hmmm!

Having said all this, are there really any significant audible differences between most cables that can be consistently identified by experienced listeners? The answer is simple: very seldom! Those who claim otherwise do not fully grasp the power of the old Placebo-Effect - which is very alive and well among even the most well-intentioned listeners. The placebo-effect renders audible signatures easy to detect and describe - if the listener knows which cable is being heard. But, take away this knowledge during blind or double-blind listening comparisons and the differences either disappear completely or hover close to the level of random guessing. Speaking as a competent professional engineer, designer and manufacturer, nothing would please me and my company's staff more than being able to design a cable which consistently yielded a positive score during blind listening comparisons against other cables. But it only rarely happens - if we wish to be honest!

Oh yes, we have heard of golden-eared audiophiles who claim to be able to consistently identify huge, audible differences between cables. But when these experts have visited our facility and were put to the test under carefully-controlled conditions, they invariably failed to yield a score any better than chance. For example, when led to believe that three popular cables were being compared, varying in size from a high-quality 12 AWG ZIP-CORD to a high-tech looking cable with a diameter exceeding an inch, the largest and sexiest looking cable always scored best - even though the CABLES WERE NEVER CHANGED and they listened to the ZIP Cord the entire time.

Sorry, but I do not buy the claims of those who say they can always audibly identify differences between cables, even when the comparisons are properly controlled to ensure that the identity of the cable being heard is not known by the listener. We have accomplished too many true blind comparisons with listeners possessing the right credentials, including impeccable hearing attributes, to know that real, audible differences seldom exist - if the comparisons are properly implemented to eliminate other causes such as system interactions with cables, etc.

Indeed, during these comparisons (without changing cables), some listeners were able to describe in great detail the big differences they thought they heard in bass, high-end detail, etc. (Of course, the participants were never told the NAUGHTY TRUTH, lest they become an enemy for life!)

So why does a reputable company like DAL engage in the design and manufacture of audiophile cables? The answer is simple: since significant measurable differences do exist and because well-known and understood transmission line theory defines optimum relationships between such parameters as cable impedance and the impedance of the load (loudspeaker), the capacitance of an interconnect and the input impedance of the following stage, why not design cables that at least satisfy what theory has to teach? And, since transmission line theory is universally applied, quite successfully, in the design of cables intended for TV, microwave, telephone, and other critical applications requiring peak performance, etc., why not use it in designing cables intended for critical audiophile applications? Hmmm! To say, as some do, that there are factors involved that competent engineers and scientists have yet to identify is utter nonsense and a cover-up for what should be called pure snake oil and buzzard salve - in short, pure fraud. If any cable manufacturer, writer, technician, etc. can identify such an audible design parameter that cannot be measured using available lab equipment or be described by known theory, I can guarantee a nomination for a Nobel Prize.

Anyway, I just had to share some of my favorite Hmmm's, regarding cable myths and seemingly fraudulent claims, with audiophiles on the net who may lack the technical expertise to separate fact from fiction with regard to cable performance. I also welcome comments from those who may have other opinions or who may know of something I might have missed or misunderstood regarding cable design, theory or secret criteria used by competitors to achieve performance that cannot be measured or identified by conventional means. Lets all try to get to the bottom of this mess by open, informed and objective inquiry.

I sincerely believe the time has come for concerned audiophiles, true engineers, competent physicists, academics, mag editors, etc. to take a firm stand regarding much of this disturbing new trend in the blatantly false claims frequently found in cable advertising. If we fail to do so, reputable designers, engineers, manufacturers, magazine editors and product reviewers may find their reputation tarnished beyond repair among those of the audiophile community we are supposed to serve.

Best regards,
John Dunlavy "

Edited by Crackie on Thursday 3rd October 21:04

CoffeeTreat

28 posts

118 months

Thursday 23rd October 2014
quotequote all
I don't disagree with that - but lets be clear what he's saying. There are a whole load of electrical properties in a cable and they matter. Most cable manufacturers seem to not care about the science and just make cables and play to the ego that it cost a lot therefore it must be good and fancy marketing. He also maintains that the difference between most cables is relatively small and that for most its imperceptible.

Now I suggest everyone should replace their speaker cable with bell wire and see if they can hear a difference. If they can't then they're either deaf or already using bell wire. So at an extreme you can here a difference. Its just scale and size of gap and the usual diminishing returns rule mans most are probably beyond the point of transition.

The other thing I would venture is that the tonality of a system can change subtly with different cable and interconnect, and for that matter single and bi-wiring. I've a box of various cables bought over the years, probably the most expensive is £150 for interconnect and £500 for speaker cable and I can definitely hear a difference, as can others that aren't aware of changes and or price. The point is, just because it sounds different, doesn't mean it necessarily sounds better.

Crackie

6,386 posts

241 months

Thursday 23rd October 2014
quotequote all
Riff Raff said:
Crackie said:
CoffeeTreat said:
I just get the feeling to some a cable does nothing because its just a bit of wire.
The Dunlavy quotation here http://www.pistonheads.com/gassing/topic.asp?h=1&a... might be of interest.
It might be, if your link didn't point to a thread that's dozens of pages long. How about an Executive Summary?
Bearing in mind the link does take you to the correct page I didn't see the benefit of filling out this thread with something I'd already posted a couple of times on PH previously.


Edited by Crackie on Thursday 23 October 21:51

Riff Raff

5,086 posts

194 months

Thursday 23rd October 2014
quotequote all
Crackie said:
Bearing in mind the link does take you to the correct page I didn't see the benefit of filling out this thread with something I'd already posted a couple of times on PH previously.
I must admit I don't read every post you make on PH. Sorry if that offends you.

What TonyRPH did was the way to do it. IMHO of course.

Crackie

6,386 posts

241 months

Friday 24th October 2014
quotequote all
Riff Raff said:
Crackie said:
Bearing in mind the link does take you to the correct page I didn't see the benefit of filling out this thread with something I'd already posted a couple of times on PH previously.
I must admit I don't read every post you make on PH. Sorry if that offends you.

What TonyRPH did was the way to do it. IMHO of course.
Fair enough, I wasn't offended at all. I thought this post was huge already and that people would be OK with making the effort to click their mouse once to find the letter.

More importantly, what did you think of the points made in Dunlavy's letter ?

probedb

824 posts

218 months

Friday 24th October 2014
quotequote all
TonyRPH said:
I can't provide any blind test proof - but with a poorly designed amp that suffers badly from EMI - it's not inconceivable that these cables would actually make it sound better.
Thanks for the link smile And yes I guess it could do anything for better or worse!