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  1. #26
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    Quote Originally Posted by jbangelfish
    Aluminum wiring for example was approved for electrical applications in spite of their tests which failed it. Why would they do that? Because big companies like ALCOA have lots of money and stand to lose a great deal if they were unable to sell their product. Many people died from fires that were caused by aluminum wire. The problem has been solved by creating different terminals for aluminum wire but they didn't exist when the UL approval originated.
    I don't know what your are referring to about UL approving products which failed their tests but aluminum wiring was approved by the National Electrical Code which is a subchapeter of the National Fire Code. The people who review and change these codes are experts in the areas of fire safety, electrical safety, and loss prevention. Their main customers are the insurance companies which pay off when there is an accident resulting in injury, death, or loss of property. They have a vested interest in preventing any such losses. Municipalities have the option to approve these codes as part of their own laws or as in the case of New York City, to write their own codes.

    Aluminum wiring is pefrectly safe when used the way it was intended. However, the alloys used in the era when they were approved were relatively soft and underwent "plastic deformation" over time. Switches, receptacles, and other devices approved for use with aluminum wiring had springs which maintained adequate pressure to keep good contact over the years. But many homeowners and perhaps inexperienced or untrained Saturday afternoon electricians and handyman types used the hardware intended for copper wire instead. Over time, these connections became loose and would arc causing the aluminum to burn which further increased contact resistance, causing them to get even hotter from further arcing, and eventually could cause a fire. BTW, this can happen even with copper wire. Today large companies "thermoscan" all electrical connections during routine annual maintenance or when a problem is suspected. I saw a 200 amp GE safety swich melt down due to loose connections, the obvious result of long term inattention to maintenance. Luckly, it was discovered before an accident. As for UL, they merely verify that the equipment will safely do what the manufacturer claims it will under the conditions of use he specifies. They cannot protect people from themselves if they do not know what they are doing and screw up.

    It might interest you to know that aluminum wire is still used today by utilities for high voltage feeder cables but the people who use it are well trained tradesmen and professionals who know exactly what they are doing. Aluminum has been taken away from the homeowner for his own protection from lack of knowledge and skill.

  2. #27
    300A
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    Aluminum wire was a disaster

    Why anyone would pass aluminum wire as safe is beyond explanation.

    When aluminum wire was allowed, many structures used them, with passing inspections, and fire resulted. Spring loaded connectors etc. aren't the long answer as corrosion will eventually cause problems, plus more contact points. Aluminum just isn't that good.

    I for one would never use aluminum wire unless Forced to.

    Positron



    Quote Originally Posted by skeptic
    I don't know what your are referring to about UL approving products which failed their tests but aluminum wiring was approved by the National Electrical Code which is a subchapeter of the National Fire Code. The people who review and change these codes are experts in the areas of fire safety, electrical safety, and loss prevention. Their main customers are the insurance companies which pay off when there is an accident resulting in injury, death, or loss of property. They have a vested interest in preventing any such losses. Municipalities have the option to approve these codes as part of their own laws or as in the case of New York City, to write their own codes.

    Aluminum wiring is pefrectly safe when used the way it was intended. However, the alloys used in the era when they were approved were relatively soft and underwent "plastic deformation" over time. Switches, receptacles, and other devices approved for use with aluminum wiring had springs which maintained adequate pressure to keep good contact over the years. But many homeowners and perhaps inexperienced or untrained Saturday afternoon electricians and handyman types used the hardware intended for copper wire instead. Over time, these connections became loose and would arc causing the aluminum to burn which further increased contact resistance, causing them to get even hotter from further arcing, and eventually could cause a fire. BTW, this can happen even with copper wire. Today large companies "thermoscan" all electrical connections during routine annual maintenance or when a problem is suspected. I saw a 200 amp GE safety swich melt down due to loose connections, the obvious result of long term inattention to maintenance. Luckly, it was discovered before an accident. As for UL, they merely verify that the equipment will safely do what the manufacturer claims it will under the conditions of use he specifies. They cannot protect people from themselves if they do not know what they are doing and screw up.

    It might interest you to know that aluminum wire is still used today by utilities for high voltage feeder cables but the people who use it are well trained tradesmen and professionals who know exactly what they are doing. Aluminum has been taken away from the homeowner for his own protection from lack of knowledge and skill.

  3. #28
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    I would be careful

    Debbie. I have little confidence in CR as I have worked on what they considered the best products. What they thought was the best turned out to be a piece of junk in reliability terms. That, alone should disqualify a product from being the best.

    To me, they had no idea what real quality meant.

  4. #29
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    Nonprofit?

    How much money does a hospital make? They are non profit. How much money does the Catholic church have? If money is involved, I don't trust anyone and rest assured that some people are making a great deal of money working for and running CR, CU, UL and any other initials that you can think of.
    So far, I am able to question their methodology, their integrity and their conclusions. That's what makes this the good ol' USA.
    Bill

  5. #30
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    Quote Originally Posted by 300A
    Why anyone would pass aluminum wire as safe is beyond explanation.

    When aluminum wire was allowed, many structures used them, with passing inspections, and fire resulted. Spring loaded connectors etc. aren't the long answer as corrosion will eventually cause problems, plus more contact points. Aluminum just isn't that good.

    I for one would never use aluminum wire unless Forced to.

    Positron
    Either you didn't read what I wrote or you just don't want to listen. As for using aluminum today, you aren't allowed to. The risk of someone who is not trained or skilled as an electrician or an electrical engineer making what could eventually become a fatal mistake is too great.

    Aluminum was useful because it was a cheaper than copper and in trained hands a satisfactory alternative. I think most or all high voltage feeders in use are aluminum. BTW, they use different alloys today which are much harder and therefore don't have the same shortcomings as those used in the old days. Aluminum is also light and strong, a major consideration for long runs of heavy overhead cables.

  6. #31
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    Quote Originally Posted by jbangelfish
    How much money does a hospital make? They are non profit. How much money does the Catholic church have? If money is involved, I don't trust anyone and rest assured that some people are making a great deal of money working for and running CR, CU, UL and any other initials that you can think of.
    So far, I am able to question their methodology, their integrity and their conclusions. That's what makes this the good ol' USA.
    Bill
    Plenty of hospitals are for-profit operations with investors and stockholders to account for. Even at nonprofit hospitals, you can't expect doctors to work for free.

    You seem to confuse nonprofit with nonrevenue, and those are two entirely different concepts. ALL nonprofit agencies have some kind of administrative overhead that they need to pay for -- they would not be able to function otherwise. Staffers and professionals do not work for free, their offices are not free, the phone company and utilities do not donate their services, etc. Money or some other expression of economic exchange value has to be involved. In order to conduct research, you need to hire people who can develop the methodologies and carry out the testing. There's nothing suspicious about a nonprofit company that pays its staffers. If you don't trust anything where money is involved, then there's nothing you can trust, including yourself, since I'm sure you don't work your job for free.

    You can do all the questioning you want, no one's stopping you or questioning your right to do so. But, that doesn't by definition make your suspicions and assertions factual.

  7. #32
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    Aluminum is used as you say

    Quote Originally Posted by skeptic
    Either you didn't read what I wrote or you just don't want to listen. As for using aluminum today, you aren't allowed to. The risk of someone who is not trained or skilled as an electrician or an electrical engineer making what could eventually become a fatal mistake is too great.

    Aluminum was useful because it was a cheaper than copper and in trained hands a satisfactory alternative. I think most or all high voltage feeders in use are aluminum. BTW, they use different alloys today which are much harder and therefore don't have the same shortcomings as those used in the old days. Aluminum is also light and strong, a major consideration for long runs of heavy overhead cables.
    It is used exclusively by Commonwealth Edison for all overhead and underground wiring. The new terminals have solved most of their problems but not all of them. Aluminum expands 38% more than copper under load, this was the problem, eventually becoming loose and arcing. The springs you mention have taken care of most of this. It was first outlawed for use in mobile homes and perhaps has gone on to be outlawed in all homes. It was used for many years in these applications and did cause many fires. It took a few years for them to figure out what was going wrong, not from a lack of skill on the electricians part but from a lack of compatible terminals.

  8. #33
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    Nope, I don't work for free

    Quote Originally Posted by Woochifer
    Plenty of hospitals are for-profit operations with investors and stockholders to account for. Even at nonprofit hospitals, you can't expect doctors to work for free.

    You seem to confuse nonprofit with nonrevenue, and those are two entirely different concepts. ALL nonprofit agencies have some kind of administrative overhead that they need to pay for -- they would not be able to function otherwise. Staffers and professionals do not work for free, their offices are not free, the phone company and utilities do not donate their services, etc. Money or some other expression of economic exchange value has to be involved. In order to conduct research, you need to hire people who can develop the methodologies and carry out the testing. There's nothing suspicious about a nonprofit company that pays its staffers. If you don't trust anything where money is involved, then there's nothing you can trust, including yourself, since I'm sure you don't work your job for free.

    You can do all the questioning you want, no one's stopping you or questioning your right to do so. But, that doesn't by definition make your suspicions and assertions factual.
    Someone just stated that they are non-profit and this must clear them of any misinformation or wrongdoing. It doesn't. How did they rate those Scotch VHS tapes as #1? Were they just inept? It was clear that these were inferior tapes the first time you used them. I'm skeptical of anything that they print. Sorry, it doesn't really matter what I think anyway. If you like them, use them. Many people do.

  9. #34
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    It is rather odd

    how so many people can criticize CU's speaker testing methodology, and I would bet that most of these same people have NO testing methodology of their own. They merely conduct sighted listening tests wherein they might compare one speaker to another. No double-blind. No live reference. No methodology, and rather vague criteria.

    I think people criticize CU's speaker testing methodology because they do not like having their sacred cows gored.

    I believe CU does publish their frequency response curves, so one can rerank the speakers based on how one evaluates the relative merit of the different response curves.

    I believe someone here once published a Magnepan response curve from a magazine without realizing that those response curves are recorded with mics at 1 meter and that is way too close to measure active diaphragm panels that are 6 feet tall. Most cones act as point sources so the 1 meter mic placement will work.

  10. #35
    300A
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    Totally different scenario

    "Either you didn't read what I wrote or you just don't want to listen. As for using aluminum today, you aren't allowed to. The risk of someone who is not trained or skilled as an electrician or an electrical engineer making what could eventually become a fatal mistake is too great."

    That is exactly why it shouldn't have been recommended in times past. IF electrical enginners don't understand what is going on, do you think local inspectors have the training? Some people weren't thinking.


    "Aluminum was useful because it was a cheaper than copper and in trained hands a satisfactory alternative. I think most or all high voltage feeders in use are aluminum. BTW, they use different alloys today which are much harder and therefore don't have the same shortcomings as those used in the old days. Aluminum is also light and strong, a major consideration for long runs of heavy overhead cables."

    Since when is aluminum cheaper than copper? High voltage feeders etc. can use aluminum because of properly trained people and properly scheduled checks to prevent problems from developing. Alot different than commercial, such as bldg and houses which have virtually no checks once installed.

    The problem, back then, with aluminum is that it didn't have "spring" like copper does. So once it gives, it doesn't spring back. Temp changes etc. will cause it to come loose from the connection.

  11. #36
    RGA
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    Quote Originally Posted by Mash
    how so many people can criticize CU's speaker testing methodology, and I would bet that most of these same people have NO testing methodology of their own. They merely conduct sighted listening tests wherein they might compare one speaker to another. No double-blind. No live reference. No methodology, and rather vague criteria.

    I think people criticize CU's speaker testing methodology because they do not like having their sacred cows gored.

    I believe CU does publish their frequency response curves, so one can rerank the speakers based on how one evaluates the relative merit of the different response curves.

    I believe someone here once published a Magnepan response curve from a magazine without realizing that those response curves are recorded with mics at 1 meter and that is way too close to measure active diaphragm panels that are 6 feet tall. Most cones act as point sources so the 1 meter mic placement will work.

    There are many ways to measure a speaker...the inept totally uselss way is on reference axis at 1 meter - which is the way most of them do it. At least those making incompetant magazines and speakers. But the speakers are cheaper to make - show a nice graph and the profit margin soars.

    Hi FI choice has a panel of listeners and they listen blind...and apparently they measure aspects that might acually resemble the sound you hear...which is why most of the time their GOOD measurement matches the "Perceived" good sound...unlike the reviews/measurements att soundtstage or Stereophile where the measurer differes from the subjective.

    They "should" agree. The test NEEDS to account for the subjective.

    This does not even mean i agree with Hi-fi Choice. Though looking their reviews over - most of the time they get it right...so I'll go with Paul messenger's measurements.

    Measurements are used to help support statistics, Statistics are also used to provide correlations. Like hi school studen't marks will stay the same or drop once they get into college. That is the statistically scientific trend - not in my case - I went from C's to A's.

    Statistics are a miserable way to live your life...My math professor rolls his eye's when he has to teach stats. There's math, bad math and there is statistics. Nothing overtly wrong with blind listening...the stats part of it however is where the scientists part from the engineers.

  12. #37
    Forum Regular Woochifer's Avatar
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    Quote Originally Posted by RGA
    There are many ways to measure a speaker...the inept totally uselss way is on reference axis at 1 meter - which is the way most of them do it. At least those making incompetant magazines and speakers. But the speakers are cheaper to make - show a nice graph and the profit margin soars.
    "most of them"? Most magazines out there do NO measurements whatsoever, so I don't see what point you're trying to make here. And aside from S&V and CR, most of the printed and online publications that do speaker measurements make several off-axis measurements, and do not limit their measurements to the frequency response. Stereophile also does spectral decay, impulse response, impedance, and box resonance measurements, all of which say something about different aspects of a speaker's performance.

    I have no idea what you're trying to imply by bringing up the conspiratorial profit margin remark. That speakers that measure well on-axis are cheaper to make? That would be quite a statement considering how well the $80,000 Dynaudio Evidence Master measures, and how poorly the much less expensive Bose Acoustimass systems measure.

    Quote Originally Posted by RGA
    Hi FI choice has a panel of listeners and they listen blind...and apparently they measure aspects that might acually resemble the sound you hear...which is why most of the time their GOOD measurement matches the "Perceived" good sound...unlike the reviews/measurements att soundtstage or Stereophile where the measurer differes from the subjective.

    They "should" agree. The test NEEDS to account for the subjective.
    Why "should" they agree? Subjectivity is what it is, subjective. We hear diffrerently and have differing opinions of what sounds are supposed to sound like and have differing opinions as to what sounds good. Unless Stereophile's measurements are significantly different than what HiFi Choice's measurements say, then the problem is in the SUBJECTIVE evaluation, not the objective measurements. I have an opposite take, I think that speaker tests need to account for the objective, since most published speaker reviews put the emphasis on the subjective.

    Quote Originally Posted by RGA
    Measurements are used to help support statistics, Statistics are also used to provide correlations. Like hi school studen't marks will stay the same or drop once they get into college. That is the statistically scientific trend - not in my case - I went from C's to A's.
    Statistics are either descriptive or predictive. In social science, a correlation coefficient of 0.6 is about as high as you can expect in any predictive hypothesis. Just because you went against a more generalized trend with your grades does not discount the validity of the predictive conclusion, since anytime you're dealing with socioeconomic studies, a researcher will never infer one-to-one causality when dealing with large numbers of people and backgrounds that are not easy to control for (for example, no way of controlling for the curriculum, grading criteria, quality of instruction, etc.). Just because you did not follow the trend does not discount the fact that many others did. Also, the aspect of the example that you left out is that the correlation between high school grades and college grades decreases with every successive year, to the point that there's a more or less spurious correlation by the time a student reaches their senior year in college. Same thing with scores on standardized college entrance exams.

    Quote Originally Posted by RGA
    Statistics are a miserable way to live your life...My math professor rolls his eye's when he has to teach stats. There's math, bad math and there is statistics. Nothing overtly wrong with blind listening...the stats part of it however is where the scientists part from the engineers.
    Just about every professor at research universities cry foul any time they have to teach ANY lower division classes, whether that be calculus, trigonometry, precalculus, introductory statistics, introductory chemistry, introductory physics, history overview, introductory psych, etc. On the other hand, the two professors that I had for advanced statistics absolutely loved teaching that subject, since they could integrate their own research into the coursework, which made it more challenging and interesting for the students.

    I don't find statistics miserable at all. I use them at work all the time, and occasionally construct statistical models for forecasting purposes. But, if you don't understand what their appropriate usage is, or what their limitations are, then I guess statistics can be a miserable exercise.

    The issue with statistics is not with the theory, but with how people apply them. There are many ways of interpreting and misinterpreting statistics, and problems with stats is in that part of it, not the theory behind it. Calling it bad math is disingenuous.

    Also, how is it that scientists and engineers use statistics differently? In the rhelm of speaker design, statistical modeling can be used to decide on the parameters around which designers build their speakers. I know that Adire Audio used this process to come up with hundreds of potential driver design configurations, and they narrowed it down to those designs that the model predicted would best fall within the performance and cost parameters that they specified. By going through this process, they only needed to build a handful of prototypes rather than hundreds of them, an important factor considering how small a company they are. I don't know of a single speaker designer out there right now that doesn't do some sort of measurement during the design process.
    Last edited by Woochifer; 11-26-2003 at 06:35 PM.

  13. #38
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    Smokey: Beware the "unbiased" source

    CR is a horribly poor source for finding audio products. Anyone recommending something off of a CR audio test should be immediately disregarded...especially speakers.

    With that said, let me add in the disclaimers. I do not think that, outside of another Bose lawsuit and related expenses, CR speaker tests are biased, only that they, in order to create a testing scheme that is easily repeatable and quick, have overlooked some HUGE problems in their methodology. Their electronics testing was best stated a few years back, something akin to "buy the cheapest receiver with the most watts and inputs". If you are happy with that, disregard the rest of this post and go back to reading CR's audio recommendations.

    I'm not going to spend a whole lot of time covering what was so well covered in a previous post. Suffice it to say that equal weighting across the audio spectrum is a non starter, and dispersion is everything in a speaker, as is room interaction. I once posted a selection of recommendations for them, one included the NRC's essential testing method using listeners placed in different places in the room and writing down their observations. This could be done with as little as two or three people, albeit far more time consuming. What they are doing right now is a complete disservice to their legions of readers. The good part is that many people seemed to have figured this out. I still have some friends that sell audio and someone carrying in CR or referring to it in an audio sale has fallen from a multiple time per week to near "0". Most of them go months before seeing or hearing them mentioned in an audio sale. These guys work at places from Best Buy and Circuit to mid-fi independent dealers. What they are doing wrong could be fairly easily improved without adding a ton of complexity, but they really don't have much interest in changing. I can only tell you that I made a really good living for a number of years in the mid 80s to early 90s showing just how wrong CR was in audio.

    Now, Smokey. Please, go out and listen to those Sony speakers. If you can, go do it at a Best Buy store. Then listen to the little Athena bookshelves in the same display. You will soon forget about Sony and CR. There is more to a speaker than cone materials. Sony is using real or simulated Kevlar as a gimmick to get some attention. They are not engineering a driver or speaker system to get any of the potential benefits of the material, they are just trolling for the easy sale. The performance of the current (and past) Sony speakers have been fairly sub-par given their price. They fall into the "happy face" EQ realm. Boosted "mid highs" and "mid bass" without good extension on either, muddy bass and boxy sounding midrange. The Athena will give you a good picture of what a pretty good speaker will sound like.

    The best advice I can give to finding speakers is to use your ears. Be suspicious of any speaker that catches your attention on either extreme immediately. Listen to the midrange first, especially tonal quality and "placement" of a vocalist in relationship to the music (Yes, I'm a firm believer in music testing over the cartoonish aspects of home theater) then listen to see if the speakers "disappear", or if your ears keep locking in on them. If your ears keep locking in on the speakers, it typically means poor dispersion characteristics, and if the midrange sounds boxey and far behind the music, you've found one of the many "happy face" speakers foisted on an ignorant public. (Keep the "happy face" speakers for the kids who want the "boom and sizzle")
    Next, the highs and bass. You want detail and definition, not the aforementioned "boom and sizzle". Find a speaker that sounds "right" to your ears. Forget brand names, number of drivers, size (as long as it fits in your room), better is better than bigger, big woofers facing forward are a very evil thing, and deep bass is best served with a subwoofer (don't buy one that plays only one note really well...that severely limits your choices in that category). Oh yeah, don't forget to check out speakers one level above and below your price range. It would really suck if you spent $400 on a nice pair but found ones that blew you out of the water for $500.

    Good luck,

    Space
    Space

    The preceding comments have not been subjected to double blind testing, and so must just be taken as casual observations and not given the weight of actual scientific data to be used to prove a case in a court of law or scientific journal. The comments represent my humble opinion which will range in the readers perspective to vary from Gospel to heresy. So let it be.

  14. #39
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    Quote Originally Posted by Debbi
    The 2003 guide reviews Bookshelf speakers(page 301). Again Bic dv62si scored higher in accuracy than B & W 602 s2 and much better than klipsch SB3s I own. The B & W runs 550 and the klipsch 450 while Bic at 200 and discounted on net a number of places for 110-120/pr.Pioneer, Bose and cambridge sound also have high rated speakers at low cost. I realize that CR is not the bible but they do test these things. I note also that Sony is making well reviewed reasonable speakers with Kevlar cones like B & W. It is afterall just a piece of plastic. Its becoming obvious that good speaker design parameters readily available and no reason why one mfg cant knock off an approximation of anothers for a fraction of the cost.It may be time for us to consider some of the alternatives to high priced cadre of names thrown around on this forum. As a bonus, a lot of these low cost, high value speakers are made by well established companies with a excellent track history....the highest rated on the list is the Pioneer S-DF3-k for 350/pr prior to discount which can be considerable. When is the last time someone touted Pioneer or Sony speakers on this forum? Hey, when the 57 chevy came out, they were seen as low cost mass market entries and became classics...By the way, I am among the guilty and have been looking at B & W, Paradigm etal myself. For the cost of a couple of meals out, I might try those Bics and report on them.
    I never considered Sony speakers before, but after hearing them I purchased the SS-MB350H's. IMO I think they're excellent speakers at a very low cost.

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