First a little background on this subject. I am not an expert on blind testing so take everything below for what it's worth. But as I see it, people who believe in the benefits of blind testing audio equipment basically say that if you can't hear the difference in a double blind test then you're only fooling yourself. There is no difference. The people against using blind testing have a host of reasons why they aren't accurate. Such as length of time, unfamiliar equipment and rooms etc. etc. They believe there are audible differences in say cables etc that are masked by the blind test procedure.

Thinking on this subject I realized that I have never read about a blind test procedure where proven differences were heard with audio components. In other words, let's take a component in the audio chain where almost everyone will agree there are sonic differences such as speakers or cartridges. I don't know of anyone who would argue that there are no audible differences between different brands of speakers. So lets use them for starters. One would assume that just about anyone could tell the difference very close to 100% of the time, in a blind test, between a full range floor standing speaker and a mini monitor. But before we assume, I would like to see it done. If that assumption turns out to be correct then let's try two different speakers with similar bass responses. I think this would be considerably more difficult. But again you would "assume" that most people would be able to tell the difference almost 100% of the time between these speakers as well. Then drop down to testing preamps, amplifiers etc.

My point is this, Having the bench marks created using the tests above, we could then move on to more difficult to hear components such as cables etc. In other words if people had trouble telling apart even speakers, cartridges and preamps using blind testing, this would help prove the point of view that the tests are not an accurate way of showing audible differences. If the above tests show that people can consistently hear differences between speakers, cartridges and even amps and preamp, then this would be a mark for the double blind testers. But instead of assuming people can hear gross differences from components such as speakers I would like to see it done first.

Maybe I'm wrong. Can someone show me a double blind test using audio components of any kind that shows a consistent verifiable difference was heard by a number of people.

Just food for thought.

I think the usual findings are kind of no-brainers. When blind tests don't find differences in cables, that should be no surprise. Take a 50 foot run of 36 guage wire and use it for speaker connections, that's something you can probably blind test a positive result compared with say a 12 guage wire. But comparing two brands of same size copper wire is going to give a null result. The same could be said about other components that have similar performance levels. Some things are just more noticeable than others. That doesn't mean they sound or measure the same in all characteristics, but there comes a point where most people can't tell, just like a size of print they can't read.

I think speakers are the easiest components to identify in a blind test. There is such a wide range of performance levels and optimizations. Speakers are electro-mechanico-acoustic devices, so even though they have relatively simple construction, they have an impossible job. That's why each designer chooses trade-offs he optimizes for, and it's those trade-offs that expose the speaker and make it possible to identify. Mini-monitors have less bass, so you can tell them right away when compared with a speaker with a larger woofer. Horns are more directional, so they have audible cues of their own, lack of reflections and what not. As long as the differences are pretty large, you can tell them right off. But once the differences become subtle, then obviously a blind test will yield a null result.

Other interesting things such as Low Q resonances being more audible that high Q ones.

One thing is for sure - The room and loudspeakers contribute the most distortion. As for the rest well,you can do your own blind testing but certain smart alecs may dismiss the results. Does it matter if they do?

Just like politics and religion,such is audio _ it gets people passionate.

• http://www.pcavtech.com/play-rec/index.htm

This is a good test because it uses a pair of signals with exactly the same frequency harmonic content but having different phase. It prevents the listener from obtaining frequency cues that expose a difference in phase. Cancellations of certain frequencies, beat frequencies and things that make response aberrations are pretty easy to detect, but absolute phase isn't. So you're going to have a very hard time finding people that can detect a sawtooth from a reverse sawtooth in a blind test. Try it and see.

I say that if someone cannot tell the difference in a DBT between copper cables and $100/foot silver cables, then who in the world could possibly be stupid enough to pay $100/foot for silver cables, when there is no audible difference??

As I said earlier I am no expert in DBT's. However I don't think these tests are trying to show which component sounds better but instead if a difference can be heard at all. In other words, listen to Amp "A" then switch to Amp "B" did you hear a difference, yes or no. First you would have to determine if a difference between say amps or cables can be heard at all, and then you could go from there.

If there ever was a post that demonstrated why I will never allow my equipment get involved in a shoot-out, this is it.

The basic premise of the post is that since DBT's don't produce the expected results, the the TESTs are in error. Everyone knows that tubes sound better than SS, vinyl better than CD's, silver wire better than copper, etc.

DBT's are designed to identify differences between systems, not to assign rankings. If the tests you were involved in demonstrated "A" was better than "B", then the tests were flawed. Rankings are subjective and cannot be tested. Sure, some equipment will be universally agreed to be poor, or good, whatever, but this is NOT the result of a DBT test.

You like tubes and vinyl. Maybe I don't. Therefore, either my ears are flawed, I am a fool or both. Or perhaps my program material is different from yours and might need different reproduction equipment? Maybe I just don't like the fat sound of small SET's?

It has been suggested that at the next GPAF we arrange a shoot-out between Wayne's speakers and mine and whoever else wants to participate. Not going to happen. Do our speakers sound different? Sure. Do we need A-B testing to prove so. I don't think so. Our design philosophies are very different and our target audience is very different. If you were at the last GPAF, you would have seen that some folks gravitated to my suite and some gravitated to Wayne's suite. Different folks. Different ears. And this is the way it will always be with audio equipment.

Bob