Re: measuring grid chokes [message #31594 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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Re: measuring grid chokes [message #31595 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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Re: measuring grid chokes [message #31596 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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Re: measuring grid chokes [message #31597 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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Re: measuring grid chokes [message #31598 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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Re: measuring grid chokes [message #31599 is a reply to message #31586] |
Wed, 14 December 2005 17:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
colinhester
Messages: 1349 Registered: May 2009 Location: NE Arkansas
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Illuminati (3rd Degree) |
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Depending on how serious you are about this experiment, you might want to contact the local university's EE dept. I'm sure a prof would be more than willing to donate time / resources to help secure data and verify your results. Also, what thought have you given to stastical variations in manufacturing? This might prove to be intersting, depending on the winder and their QC/QA procedures.....$0.02
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Re: measuring grid chokes [message #31600 is a reply to message #31599] |
Wed, 14 December 2005 17:59 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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Hey Colin, Excellent idea. It won't do any good with the current situation. I could have God himself measure, and there would be knuckleheads comming out of the woodwork claiming that the numbers did not mean a thing. I do have access to the best, both at home and at the local University. There are also a few audio enthusiasts from work who feel the same about a well stocked lab as I do. I've a few sources of guidance, should that become an issue. And then there's the statistical variation... cheers, Douglas
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Re: measuring grid chokes [message #31601 is a reply to message #31599] |
Wed, 14 December 2005 18:36 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
MQracing
Messages: 220 Registered: May 2009
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Master |
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Hi Colinhester: Picking any one parameter or two... doesn't even begin to tell ya the whole story... and in fact can be quite misleading. For example... take a speaker (i'm not a speaker engineer by any stretch)... how many different parameters must a speaker designer juggle to achieve an end product... what if the evaluator only looks at one parameter as the measure of goodness? What the designer probably tried to do was to juggle and optimize a wide range of parameters to get a good sounding product... not just focus on one or two parameters. I would guess any good speaker or driver designer.... say achieving the highest max flux density (as a sole parameter) were the test... I'll bet a good driver designer could meet or beat your "spec" if that was the only "spec" he had to be concerned with. same goes for tranneys... I listed 18 different parameters that a designer might consider in a magnetics design and the list was short and done on the fly... for instance we would need to add to the list... flux density... an important parameter that you would not want to totally ignore so that you could lower some other arbitrary spec (in isloation) like the dc winding resistance as just one example. If you give an engineer the task of designing a product to maximize only one or some small set of parameters and allowed him to trade off all other performance parameters... it almost becomes a trivial excercise. but that's not how good products come about... or at least not in my experience. that's my .02 dollars msl
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purpose for measuring grid chokes [message #31602 is a reply to message #31601] |
Wed, 14 December 2005 19:18 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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hey-Hey!!!, Since there is no means of measuring how good a part will sound in-circuit, we're stuck measuring single parameters, or groups of them.With these measurments, it is possible to examine circuit behaviour, or at least make predictions based on well-researched guesses. Once a circuit has the device installed, we can see how it sounds. Since no reasonable measurements exists to quantify what we think we hear, we're stuck with single parameters or groups of parameters to measure. I have yet to see a group agree on why a SE amp sounds the way it does...yet there are plenty who'd refuse to classify the amp from the un-favoured topology as listenable. Only one can be best, and that sort of thing. Turns out there *ARE* a lot of characteristics that can be measured which shed light into how an amp should sound, and where its bandwidth will start and stop. In the grid choke example, to simplify, it is operating as a low DC/high AC impedance device. Seems reasonable that its impedance across the traditional audio spectrum would be of interest. Since it is to me, and a few others, I've proposed not only to measure, but to describe the methods and equipment used to measure. The numbers are what they are, and if anybody wants to suggest ways of analyzing the data, or proposing a detailed method to gather it, I'm all ears. As to the rest of the suggestions on my design practices, I don't recall ever saying that any single parameter should be used in the design stage. Matter of fact, I have actually taken just the opposite aproach in discussions about PS DCR for examle. In God we trust, all others bring data! cheers, Douglas
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Re: measuring grid chokes [message #31603 is a reply to message #31586] |
Wed, 14 December 2005 08:52 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to previous message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18752 Registered: January 2001
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Illuminati (33rd Degree) |
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I think it would be wise to publish test results identifying the items being tested.But there is one problem. You and I both have this same sort of dilemma. Since you're pretty connected in the industry, your biases might be called into question. Better to avoid this sort of thing. The best way to do something like this is with independent confirmation. An objective outside party is not going to be questioned like you might be. Then again, sometimes it's not economically possible to send samples out to a lab. In that case, I'd say publish your findings but be careful about interpreting them. If you post an unfavorable interpretation in a public forum, you'll probably be attacked. Or if you post proudly about your own work, even in a private forum, sometimes people will react. Not that controversy is always avoidable or even bad, but if you publish interpretations of work like this, it is bound to bring some your way.
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