Quote Originally Posted by ruadmaa
Sorry RGA you lose. On double blind tests no one to date has been able to tell the difference between amplifiers. And that means comparing a receiver amp to any separate amp you care to mention. Many say they can but when put to the test they all lose. When it comes to amplifiers/receivers, you obviously don't know what you're talking about. If you feel you can tell the difference, go and take the $10,000 challenge that is offered to anyone by Mr. Clark. Many have tried, all have failed. As long as a receiver or amplifier is not driven into clipping it will sound so similar that for all practical purposes there are no differences. Please don't argue with me, as I have stated, no one to date has been able to take a double blind test and tell the difference between amps.
Actually I don't disagree with you about most results in these tests...haven taken psychology which is who should be conducting such tests i have written papers on them and conducted blind experiments -- I am well aware of the bastardized versions being propogated by the Audio Industry and the AES. I am not surprised by the reliabiltiy(in terms of getting the same results over and over). Though Martin Colloms has done DBT's for the AES where people could hear different capacitors in the amplifiers let alone different amplifiers. One can take a receiver and set everything to 2 channel flat -- listen then push the direct button -- you will hear a difference and the ONLY thing that has been done has been to remove two of hundreds of switches from the chain.

People in DBT's can;t hear lots of things they can hear when not in such wrongheaded tests -- no one can tell the difference between a recorded audio tape versus CD either. People can;t tell the difference between a record and live music which was done in the 1930s. Until you understand the psychology of why the tests don't work beyond the testing environment then it's just another engineering argument where people don;t get the science behind the tool. I'd offer a million dollars if I had it to anyone that can tell the difference between my two cd players in a blind test to statistical significance.

Trouble is and something you may not be aware of that most of the tests you read about are in the order (and it's invented with no reason behind it) a 10-16 trial set-up.

To achieve statistical significance so that you PASS the test and are confirmed as hearing a difference you need 9/10 to meet the .05 level of significance. What you don;t get told is that A) small trials are very difficult to succeed in with perception testing which is why Psychologists use in the order of hundreds. now if we did it PROPERLY in audio then did you know that if you scored just 6/10 ten times in a row with an extra mistake and got 59/100 you would ALSO meet the .05 level of significance which would ALSO mean that you could tell the difference and not likely be due to chance.

They never tell you it because they don't know it and they are too lazy and stupid to pick up the proper textbooks. So yes if you get 6/10 in their test you are a falure who can't tell the difference -- but gee if you score 59/100 then in fact you are deemed credible by science. In fact this is more credible because MORE trials reduces error and more trials is more reliable.

Part two is that the very definition of the DBT will state that you can never ever prove that unit A sounds the same as unit B.

You would be amazed at all the things that humans can do in tests and or can;t do in tests that simply do not happen or do happen in the real world. The DBT is a tool -- it is not at fault either and it is very very valuable in a number of applications - but it's used badly most of the time -- and it's not credible as you would like to think.

Also the magazine hi-Fi Choice has a listening panel review componants in a level matched blind auditioning environment which is closer to normal listneing environments(the closer it is the more Valid any test is -- and validity is a word you won't get from DBT syupporters because if they understood this bit they would not be arguing it ad nauseum.

You can read their blind level matched reviews of receivers, cables, speakers cd players. Sorry they are distinguishable.

here is the link to hifi choice of a review of an amplifier in blind listening panels http://www.hifichoice.co.uk/review_read.asp?ID=913

here is another http://www.hifichoice.co.uk/review_read.asp?ID=1883

What is really interesting is that they have had in the past the president and chief designers sit in in the blind sessions and they don;t always choose their onw stuff as best!!!