Date: Tue, 5 Nov 1996 13:08:50 -0500
From: (Dunlavy Audio Labs)
To: (bass group)
Subject: Cable Nonsense (Long)
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

" wrote

So why does a reputable company like DAL engage in the
design and manufacture of audiophile cables? The answer
is simple: since significant 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?
]
Have you ever priced out the cost of Dunlavy speaker cable
($50/ft)? It's considerably more expensive compared to
zip cord. Is Dunlavy cable a rip-off... if it sounds the same as
zip cord?

From one of his speaker cable brochures he writes
"Compared to major-brand loudspeaker cable selling for
much more, the DAL-Z.8 is truly without peer in every
category. We sincerely believe that you will detect an
audible and relevant level of difference that will justify
your consideration."

So , when he (Dunlavy) states
"We sincerely believe that you will detect an audible and
relevant level of difference that will justify your
consideration" what does that mean to you?


Best regards,
John Dunlavy

Quack, quack, quack...

Another case in point... John Dunlavy. TAS issue122. "In
designing the Aletha, we made use of anechoic chamber
measurements and listening comparisons with live voices,...
There simply were no audible differences between the live
and reproduced sound."

Good marketing or blatant fraud?

"Powell" wrote in message
...

" wrote

So why does a reputable company like DAL engage in the
design and manufacture of audiophile cables? The answer
is simple: since significant 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?
]
Have you ever priced out the cost of Dunlavy speaker cable
($50/ft)? It's considerably more expensive compared to
zip cord. Is Dunlavy cable a rip-off... if it sounds the same as
zip cord?

From one of his speaker cable brochures he writes
"Compared to major-brand loudspeaker cable selling for
much more, the DAL-Z.8 is truly without peer in every
category. We sincerely believe that you will detect an
audible and relevant level of difference that will justify
your consideration."

So , when he (Dunlavy) states
"We sincerely believe that you will detect an audible and
relevant level of difference that will justify your
consideration" what does that mean to you?


Best regards,
John Dunlavy

Quack, quack, quack...

Another case in point... John Dunlavy. TAS issue122. "In
designing the Aletha, we made use of anechoic chamber
measurements and listening comparisons with live voices,...
There simply were no audible differences between the live
and reproduced sound."

Good marketing or blatant fraud?

"Powell" wrote in message
...

" wrote

So why does a reputable company like DAL engage in the
design and manufacture of audiophile cables? The answer
is simple: since significant 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?
]
Have you ever priced out the cost of Dunlavy speaker cable
($50/ft)? It's considerably more expensive compared to
zip cord. Is Dunlavy cable a rip-off... if it sounds the same as
zip cord?

From one of his speaker cable brochures he writes
"Compared to major-brand loudspeaker cable selling for
much more, the DAL-Z.8 is truly without peer in every
category. We sincerely believe that you will detect an
audible and relevant level of difference that will justify
your consideration."

So , when he (Dunlavy) states
"We sincerely believe that you will detect an audible and
relevant level of difference that will justify your
consideration" what does that mean to you?


Marketing hype.

Best regards,
John Dunlavy

Quack, quack, quack...

Another case in point... John Dunlavy. TAS issue122. "In
designing the Aletha, we made use of anechoic chamber
measurements and listening comparisons with live voices,...
There simply were no audible differences between the live
and reproduced sound."

Good marketing or blatant fraud?

Without hearing the speakers and the choice of music, impossible to say.

" wrote in
message
link.net

So why does a reputable company like DAL engage in the
design and manufacture of audiophile cables?

I don't Dunlavy Audio do much of anything - they were sold
in 2001 or so, and seem to have drifted into obscurity.

The http://www.dunlavyaudio.com domain seems to be up for
grabs.

" wrote

So why does a reputable company like DAL engage in the
design and manufacture of audiophile cables? The answer
is simple: since significant 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?
]
Have you ever priced out the cost of Dunlavy speaker cable
($50/ft)? It's considerably more expensive compared to
zip cord. Is Dunlavy cable a rip-off... if it sounds the same as
zip cord?

From one of his speaker cable brochures he writes
"Compared to major-brand loudspeaker cable selling for
much more, the DAL-Z.8 is truly without peer in every
category. We sincerely believe that you will detect an
audible and relevant level of difference that will justify
your consideration."

So , when he (Dunlavy) states
"We sincerely believe that you will detect an audible and
relevant level of difference that will justify your
consideration" what does that mean to you?


Marketing hype.

Your original Dunlavy post was "hype," too.

Unfortunately your empirical experiences with high-end
cables is lacking as well, mr. troll .


Best regards,
John Dunlavy

Quack, quack, quack...

Another case in point... John Dunlavy. TAS issue122. "In
designing the Aletha, we made use of anechoic chamber
measurements and listening comparisons with live voices,...
There simply were no audible differences between the live
and reproduced sound."

Good marketing or blatant fraud?

Without hearing the speakers and the choice of music,
impossible to say.

Hehehe... oh please!