Burn in time for the New Tweeters?

ben62670

I wish I could act half as smart as some people, but then I would have to act 10 times as dumb. Again my ears tell me what I like best. After all my ears are what I use for listening

jcandy

ben62670 wrote: »

I wish I could act half as smart as some people, but then I would have to act 10 times as dumb. Again my ears tell me what I like best. After all my ears are what I use for listening

I spent over an hour reading papers and presentation slides before posting that reply. What preparatory work did you do?

DarqueKnight

jcandy wrote: »

I have been scouring the AES library looking for evidence that stereo (or multichannel) audio is not compatible with blind testing, but I cannot find any real evidence of this.

Do you believe that the following statements are equivalent to saying that stereo audio is not compatible with blind testing?

DarqueKnight wrote: »

1. The less trained an evaluator is the greater the need for blinding.
2. There more trained an evaluator is the less the need for blinding.

The Petri-Larmi paper I mentioned to you previously uses blind testing with with a stereo system and I have expressed no disagreement with its methodology or findings:

DarqueKnight wrote: »

The title of the paper is "Psychoacoustic Detection Threshold of Transient Intermodulation Distortion, by M. Petri-Larmi, M. Otala and J. Lammasniemi. It was published in the March 1980 issue of the Journal of the Audio Engineering Society. The abstract is as follows:

"The audible threshold of transient intermodulation distortion (TIM) was determined for the six most sensitive subjects of the previously reported test series of 68 listeners. Improved equipment, carefully controlled listening environment, a digital TIM generator, and five recorded stereophonic music samples were used. The results show that in certain types of passages of music, a trained and sensitive listener can reliably detect extremely low values of distortion. Low distortion values were perceived only as changes in sound character, and not as distortion."

On page 101 of Petri-Larmi (1980):

DarqueKnight wrote: »

"At the end of the learning period the subject was asked to indicate the distortion level he thought he could perceive in a blind A/B test."

Also:

DarqueKnight wrote: »

I have no problem with blind tests per se. I have consistently complained about the way blind tests are administered in audio trials.

DarqueKnight wrote: »

I keep telling you that if you use a type of blind test that impairs the subject's ability to receive sensory information, then yes, something the subject perceived in a sighted test can be missed in a blind test that is administered in a way that is counter to and unrepresentative of standard listening conditions.

Again, I have said repeatedly that my problem is not with blind tests, it is with the use of inappropriate blind tests, like ABX, for testing stereo systems. ABX is only one type of blind test.

jcandy wrote: »

I think you can always quote-mine papers for one-liners that appear to support your point-of-view,...

That's true, but that would only be an issue if the one-liners I quoted actually don't support my point of view. Are you saying that the quotes I provided from Toole (1994) and Bech (2006) are misleading?

jcandy wrote: »

...but my take on the literature suggests that you do not have license to assert your points 1-5 as true.

OK. When you finish scouring the AES archives, please post references that appear to show my points 1-5 to be in error. I'm sure it will be good reading. You might even end up with something you can publish.

ben62670

jcandy wrote: »

I spent over an hour reading papers and presentation slides before posting that reply. What preparatory work did you do?

What are you trying to accomplice here? Does reading make your ears more sensitive? To prepare I let the tubes/gear warm up for about a half hour.
Thanks again.
Ben

inspiredsports

ben62670 wrote: »

What are you trying to accomplice here? Does reading make your ears more sensitive? To prepare I let the tubes/gear warm up for about a half hour.
Thanks again.
Ben

Ben, I like your style. I guess I've always liked your style. Good answer! :biggrin:

[Deleted User]

Hey DK,
I believe Polk had a definite procedure for making measurements on tweeters they were evaluating. The QA guys and the transducer engineers had a strict protocol they followed when looking at all speaker components. Anything that has moving parts, especially elastic suspension needs some kind of flexing to reach its proper operation. I can't see why tweeters would be an exception.
Cheers, Ken

ben62670

inspiredsports wrote: »

Ben, I like your style. I guess I've always liked your style. Good answer! :biggrin:

Thanks. I try to dumb things down for those who over think(not calling anyone dumb(I actually think Jcandy is very intelligent). Not that I have anything against serious thought, but a true scientist sees a problem and tries to find a solution. A weak scientist just makes excuses and says they already have the solution. People like to think they know a lot more than they do. It is the humble ones that are able to make the most progress. Real scientists would spend a little more time observing the observations made.
Take care Bro.
Ben

Kenneth Swauger wrote: »

Hey DK,
I believe Polk had a definite procedure for making measurements on tweeters they were evaluating. The QA guys and the transducer engineers had a strict protocol they followed when looking at all speaker components. Anything that has moving parts, especially elastic suspension needs some kind of flexing to reach its proper operation. I can't see why tweeters would be an exception.
Cheers, Ken

Thanks Ken.

inspiredsports

This reminds me of a car I had in the shop recently, with an intermittently squeaky serpentine belt and a slight bit of a growl coming from under the hood.

The air conditioning compressor, alternator, water pump and 2 idler pulleys as well as a pulley on the crankshaft share this belt.

I noticed the squeal mostly right after starting the car on cold dry mornings, when the heater fan was placed on high and the electrical resistance defrosters were turned on.

My mechanic tested the alternator for output (with whatever measuring tool he uses for that) and the output was good, and he tightened the serpentine belt to spec (with whatever measuring tool he uses for that).

The belt squeal went away, but the slight growl was still there. He had placed the stethoscope he uses in such cases (a measuring tool) on all pulleys on that belt, and said it was inconclusive as any bad bearing could transmit it's sound to other bearings sharing the belt. He said however, that when he simply listened with his ears, he thought it "sounded" like the alternator bearing was probably the culprit, so I kept my ear on it too.

2 weeks later the alternator started groaning miserably, and then failed completely. We replaced it and all of the abnormal sounds I'd heard were gone, so I trust we've now solved the problem.

However, the tests he'd run with the measuring tools available today did not pinpoint a problem. His trained ears, on the other hand, had predicted what was wrong.