Cables that measure the same but (seem?) to sound different

Check out the forum thread on  "Audio Engineering Society and cables" from June. There is discussion of peer-reviewed, published research demonstrating that cables that have an identical frequency response can still sound different and can be perceived as sounding significantly different under blinded listening conditions - even by untrained listeners.  

@hilde45  So what is your opinion on the cable question? Do you you hear differences between cables and buy what you can afford or do you buy inexpensive cables because you don't hear any differences?

@hilde45 
Thanks for the additional info. What do you like about how the AP Crystal series interconnects and speaker cables sound in your system?

I am considering a speaker cable upgrade and will probably borrow a few cables from the Lending Library at the Cable Company so that I can listen to several possibilities in my own system. I've never heard any Analysis Plus cables as yet, but I'm open to trying something new.

As @snilf states above, "Science gets better and better at identifying, describing and quantifying what is universally subjective, and so, in principle the audible differences between interconnects must be 'measurable,' even if not yet, if they exist at all. But those still hypothetical measurements no more guarantee an agreement in preference than would a comparative chemical analysis of Chateau Mouton-Rothchild and Chateau Lafite-Rothchild."

I agree that most of the differences we hear between cables should be measurable at some point in the future, but we are not there yet. At present, we can measure some things about a cable (e.g., frequency response, resistance, capacitance, etc.), but we don't usually have a clear handle on whether anything we measured actually accounts for differences we hear between specific cables. And even when we hear a difference, it's not a given that there will be agreement about which cable is preferred. 

If you haven't actually read the AES publication I mentioned earlier in this thread, you might still want to take a look at it. It's a paper by Milind Kunchur from the U. of South Carolina entitled "Cable pathways between audio components can affect perceived sound quality." It was published in the Journal of the Audio Engineering Society in June. The study included double-blind listening trials comparing two interconnects: a balanced Straight-Wire Virtuoso and a single-ended Monster-Cable Interlink 400. After identifying significant methodological problems with the traditional "short-segment comparisons" of the ABX paradigm, the author developed and implemented an "extended multiple pass" paradigm that is actually a lot closer to what a person experiences when listening to music. (Please read the paper for more details.)

A group of 18 college students participated in the study, and these students completed a total of 59 double-blind listening trials. 43 of these 59 trials were judged correctly; the probability of this result being due to chance was p<.0005. When frequency response was measured, both cables varied by less than +/- 0.005 dB over the range of 16 Hz to 22 kHz. Resistive losses were too small to be considered important. However, the noise levels measured in the StraightWire cable were significantly lower than in the Monster cable.

The author concludes that two system configurations differing only by the interconnect pathway are audibly discernible, even by average listeners with no special experience in music or audio. The study did not complete an exhaustive exploration of all possible factors that might contribute to sonic differences between interconnects. However, electrical measurements did suggest that noise might be one factor affecting sonic performance. The author also noted, "The measurements also show that characteristics such as resistance and frequency response, that naive consumers may focus on, are irrelevant for distinguishing HEA ("High End Audio") interconnect cables."

Apparently, djones51 prefers to post about his own biased opinions rather than to consider the implications of published peer-reviewed research that calls those opinions into question. 

djones51,

I don't agree that this paper is a "confused mess," but it does have both strengths and limitations that must be considered in interpreting the results. I agree that the paper doesn't show that Straight Wire cables are consistently better than Monster cables, but this was not the goal of the study. What it does show is that a moderately expensive balanced cable from Straight Wire sounds different than a less expensive single-ended cable from Monster, when each cable is connected using its intended pathway (i.e., either balanced XLR or single-ended RCA). Because methodological limitations in prior listening studies have made it difficult to identify reliable cable differences, the cables were chosen to be as different as possible to maximize the likelihood of finding a difference during double-blind listening trials. This approach made it impossible to tease out the specific contributions of the cable topology (XLR vs. RCA) from the effects of the cable geometry, conductors, dielectrics, etc. Studies that are designed to test those specific factors should be carried out in the future.

It appears that you believe that the 2-choice stimulus-matching paradigm for the listening trials is too simple and should have employed a third choice as well. However, as the author discusses in the paper, the use of a rapidly changing ABX paradigm (or some other more complex format) is not ideal for listening trials involving musical passages. Using pilot testing with a small group of subjects, he identified problems with rapid stimulus presentations and with more demanding cognitive loads. Keeping the decisions simple and anchored to descriptors was used to maintain the subject's attention and prevent deterioration of performance due to fatigue. Most people who have participated in ABX listening trials know how frustrating it can be to have to juggle the data that go into same-different decisions and then to make rapid sonic judgments, especially when they worry that someone is trying to confuse or fool them by manipulating the way the stimuli are presented. These problems can often lead to reduced attention and performance later in a trial, even when the stimuli are simpler than complex musical passages.

It's important to clarify that the use of a "placebo" in drug trials is different than controlling for the expectations of participants when comparing differences between two audio cables. In both cases, the use of a double-blind design can be used to control for expectation bias, but neither cable should be considered a placebo because both cables actually deliver an audio signal.