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Headshell

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  1. Hier heb je weer die spectrum- analyzer- grafieken van een enkele toon met aan weerszijden op de flanken de laagresonantiepiek. http://stereophile.com/turntables/513/index4.html De volgende is van ene Josh, die me een keer heeft geprobeerd uit te leggen hoe je de dynamische compliantie berekent vanuit de gegevens van een trackingtest. http://www.mcc.sst.ne.jp/~yosh/testrecord.htm Ook hier wordt die Ladegaard-uitgave genoemd. O, hier een site die ik nog niet had gezien: http://www.audiotic.com/
  2. Hier een tekst van die Ladegaard waar zijn lucht - experimenten zijn weergegeven. Geniaal! http://www.aiko.com/roscoe/airbearingarm.html Prachtige stukjes internet!
  3. http://www.fl-electronic.de/analog/tonabnehmer.html Ook hier een stuk uit dat verhaal van Ladegaard. Gewoon overgenomen. Je ziet ook de dip in een grafiek tussen 10 en 15 Hz waar geen rubbish zit in het vinyl.
  4. Kijk wat ik nog even gevonden heb: http://www.zainea.com/multidimensionalaudio.htm In dat gedeelte over draaitafels zie je figuur 7. Daarin staat aan de rechterzijde een weergave van figuur 23 uit de AES- uitgave uit 1977 van Bruel en Kjaer, gescreven door luchtarm- uitvinder Poul Laadegaard, een van de beste audiojournalisten ooit. Ken je die uitagve? Audible effects of mechanical resonances in turntables. Geniaal. Elektroakoestiek is best leuk. Ook het feit dat echt niet elk element last heeft van overshoot, waardoor zo'n element ook daadwerkelijk beter klinkt. Net zoiets en tevens een taboe: de hogere resonantieferquenties (laagresonantie) klinken beter en geven een beter spoorgedrag. Kijk, ze kunnen je honderd keer voor gek blijven verklaren maar het kan je eigenlijk niks schelen. Voor jou blijft het een leuke hobby.
  5. Maak er dan maar de zaterdagochtendliefhebbers van Appelscha Vooruit van. Om 9 uur de aftrap en om 11 uur aan het bier. Voor de derde helft, zeg maar.... Het moet gewoon leuk blijven. Maar op dit forum word je soms ineens voor gekke Henkie uitgemaakt als dezelfden steeds weer lont ruiken. Wat heb ik verkeerd gedaan? Ik probeer gewoon iets leuks te vertellen. Wie heb ik beledigd? Ik snap ok wel eens niet alles wat iemand vertelt. Dat verklaar ik het toch ook niet ineens voor onzin? Zie je het verschil? Speel op de bal en niet op de man. Aub zeg........ Wat is er nou leuk aan om steeds weer mensen te beledingen op zo'n forum? Noem je dat hobby? Ik heb geschreven dat je onzin verkondigt en ik heb duidelijk laten zien waarom dat zo is. Kijk maar: In dat ene voorbeeld wat je gaf heeft die begrenzing van de meetketen op 20 kHz tot gevolg dat de frequentiekarakteristiek steil afvalt bij 20 kHz. De conclusie die jij daaruit trekt is daarom verkeerd. Je houdt het leuk door niet te gaan zeuren als de bal tussen je benen wordt doorgespeeld. Anders kun je misschien beter gaan korfballen. Goed. Die Dynavector loopt missshien in dit geval zo ver door, dat het eind wel afgekapt moet zijn. Ik bedoel de twee grafieken even te laten zien. dan weten we wat ik voor ding in gedachten heb. En die fig 5 daar had ik niet bij gezien dat het iets anders is. Maar een spectrum- analyzer- figuur van 1 toon ziet er dus eender uit. Ik wil het best bekenne, als ik me ergens vergis. Maar als ik dat verschijnsel tussen de kont van een niet- afgekapte frequentiekarakteristiek vergelijk met de opgaande bocht van de blokgolf dan zit daar echt overal binnen het karakter van het element gelijkenis in. Die redactie had het gezien en ik kan het alleen maar beamen. Ik hoef toch niet net als de gemiddelde forumbezoeker overal bot tegenin te gaan? wat heb ik daaran? Als ik dat ook bemerk dat kan ik alleen maar concluderen dat het gek is, maar waar. Ik heb net als die redactie ook geen theoretische verklaring. maar het is overal echt overeenkomstig in 3 van die verzamelboekjes die ik heb. nou , dan hoef ik het toch niet te ontkennen? Ik denk ook, dat het verschil in de oploopbocht van de blokgolf zijn weerslag vindt in de reproductie, net als de aard van de 2 zijbanden op de grafiek van de spectrumanalyzer. Dus een afgang? In de ogen van eentje die je graag ziet afgaan natuurlijk wel. Dat gun ik hem. Zijn feestje. Dan kijk ik weer eventjes naar die overeenkomsten en dan zeg ik tegen mezelf: beter laat je ze lekker gewoon lulle.....
  6. Nou , dan zou ik dit soort inspanningen maar onzin vinden als ik jou was.... http://www.diy-systems.com/ Begin dan zelf met consequent zijn, als je het zo eens bent met de mening van zo iemand. Ben je zelf ook zo gauw tevreden= Waarom hebben we dit forum dan nog=
  7. Nee, maar het winnen van een drag-sprintje wel. Zonder dollen: Bose wordt inderdaad duur verkocht.... Alleen snap ik het "vooroorlogse" niet. Heel veel oude technieken (buizen is een goed voorbeeld) zijn nog niet voorbijgestreefd door technieken van deze tijd (klasse d in het geval van buizen). Ook is (voor mij) papier als konusmateriaal superieur aan aluminium, keramiek en plastic helemaal. Er zijn zeker dingen verbeterd na de oorlog (de platenspeler bijvoorbeeld), maar er zijn ook nog veel goede dingen uit de oude boeken te halen. Daarmee heeft Bose niets te maken, dat vind ik pure misleiding en oneerlijk. Degenen die hier blij mee zijn, hebben waarschijnlijk teveel geld gecombineerd met een lage kwaliteitsdrempel of hebben nog nooit iets anders gehoord dan hun reisradio. IMO dan. Overigens vind ik 47Labs niet duur. Precies. Maar om even het facet "vooroorlogse technologie" te benadrukken: Dr Anwar Bose heeft nog nooit in zijn carriere een echte dometweeter in een van zijn Bose- producten getolereerd, Hij heeft er steeds genoegen mee genomen, dat zijn klanten in het tweeter- gedeelte van zijn grote catalogus telkens moest lezen: 61 mm tweeter. Laten we eens goed bekijken wat hier wordt bedoeld: eigenlijk niet meer dan een papieren conusluidspreker met een nominale diameter van 61 mm. Puur een soort autoluidspreker van het model breedbandweergever. Als je dat niks zegt: ok. Maar in feite laat je heel het gebied boven zo'n 3 tot 4 duizend Hz. over aan een tweetertechnologie waar we sinds halverwege de zeventiger jaren al geen genoegen meer mee hoeven nemen als we een muzikaal wat beter verantwoorde weergave wensen. Decennia lang echter hebben tientallen fabrikanten het dome- tweeter- principe nog verder ontwikkeld vanaf het niveau van de eerste dome- tweeters. Conclusie: de hogetonenweergave van alle Bose/ producten ligt vele ontwikkelingsslagen achter bij andere luidsprekerprodukten uit dezelfde prijsklasse. Ik durf dit niet eens afzeiken van een fabrikaat te noemen. Hij tolereert zelf niet eens de normaal gangbare technologie. WANT: Meneer Anwar sorteert het gewoon niet. Punt uit. We hebben het niet. Het is er niet. Kom er niet om. Pech. Hij zal het zelf toegeven. Want hij vind het volkomen onbelangrijk. Hij is het dus gewoon zelf met me eens. Kan niet anders. http://www.perrymarshall.com/marketing/bose.htm :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::: Bose FAQ version 1.0 August 1995 compiled by Bert Laney (laney@coltrane.colorado.edu) from information and opinions provided by participants on the rec.audio.* newsgroups Index ^^^^^ 1.) Purpose of FAQ 2.) Other Speaker Brands 3.) Bose Marketing 4.) Bose Research 5.) Bose Innovations 6.) Bose Engineering and Design 7.) Bose Popularity 8.) Bose Repairs 9.) Newsgroup Opinions on Bose 10.) Magazines and Bose 11.) Bose and Litigation 12.) An Aside 13.) How to Listen to Bose 14.) How to Choose a Bose Dealer 1.) Purpose of FAQ ^^^^^^^^^^^^^^^^^^ New-comers to the audio newsgroups often ask about Bose. Their interest is often inspired by a sale, in which Bose speakers are offered at a seemingly irresistible price, and the poster feels a strong urgency to buy before the sale ends. If this FAQ does nothing else, at least rest assured that Bose products go on sale frequently and, when this sale ends, there will be another soon. In fact, you can often receive the sale price after the sale ends just by asking. So take your time, listen carefully, and compare! The usual naive request for information about Bose is often followed by a flame war, often to the original poster's great surprise. While Bose may be "The Most Respected Name in Audio" --- according to the Bose marketing department --- Bose gets little respect from most of the participants in the audio newsgroups. In fact, moderate to strong anti-Bose sentiments outnumber pro-Bose sentiments perhaps 20 to one on the audio newsgroups! However, there are always at least two staunch defenders of Bose. Perhaps because they face such overwhelming odds, the Bose defenders tend to phrase their arguments in brief and repetitive ways, which almost everyone else finds extremely irritating, especially after several months of exposure. The flavor of this debate has to be personally experienced to be truly appreciated. But, as a feeble attempt to duplicate it, here is the structure of a typical exchange: NEWBIE: Does anyone have any opinions about Bose speakers? FIVE RESPONSES: There are better speakers for the money including brands X, Y, and Z BOSE DEFENDER: But Bose speakers offer superior design. They're the most popular speaker in the world, and for good reason. TEN RESPONSES: Popularity does not equal quality. (Many long detailed rebuttals to the Bose defender. Tone tends to be slightly hostile since they've done this several times before. Some are very hostile --- "Bose sucks!!!") BOSE DEFENDER: No. You're all wrong. FIFTEEN RESPONSES: What?! (Many more long posts explaining again why they are right) BOSE DEFENDER: But Bose is a large corporation with excellent customer service. Other smaller companies may fail, leaving you without service. TWENTY RESPONSES: Good service for a poor quality product? So what? (Many more detailed responses about the problems they perceive with Bose, plus more "Bose sucks!!!" posts) BOSE DEFENDER: Bose is a very popular speaker. More people buy Bose speakers than any other speaker, and Bose has very high customer satisfaction rates. TWENTY FIVE RESPONSES: Agggh!! We just explained that quality does not equal popularity. Can't you read? Are you an IDIOT? BOSE DEFENDER: No. I'm not the idiot, you're all idiots. This newsgroup is populated by a small clique of crazy "audiophile" types who spend hundreds of dollars for cable that doesn't even make a difference. NEWBIE: (forgot about the newbie didn't you!) (in a weak voice) I want my mommy. This goes on ad infinitum until everyone is heartily sick of it, and the debate fades. A few weeks later, someone asks about Bose again, and it starts all over. It should be noted that not every Bose supporter always debates as described above, any more than every Bose detractor always debates by saying "Bose sucks!" This FAQ is a summary of information and opinions posted on the net in the continuing Bose debate. It is intended to inform the beginner about Bose products in particular and, to some extent, speakers in general. Furthermore, it is intended to reduce the unproductive Bose flame-wars in the future. This FAQ is a living document, which will be changed as more information and opinions appear. In fact, the compiler encourages and actively seeks further contributions from both Bose lovers and Bose haters, and even the Bose corporation. The compiler of this FAQ has not personally listened to Bose speakers in quite some time and, in that sense, has no strong personal opinions on the sound of Bose speakers. The compiler does feel, however, that many of the arguments that have been made in favor of Bose are weak, and this document reflects that judgement. 2.) Other Speaker Brands ^^^^^^^^^^^^^^^^^^^^^^^^ Suppose that, for some reason, you either decide not to purchase Bose speakers, or you wish to compare Bose with other speakers. What other speakers should you consider? A complete answer to this question is outside the scope of this FAQ --- consult the "Good Sound for Cheap FAQ." But as a short answer, some brands names worth considering include PSB, Paradigm, Theil, Mirage, Definitive Technology, B&W, Radio Shack LX5 (designed by Linaeum), Magnepan, RDL, KEF, NHT, Signet, Infinity, Spica, Energy, Quad, Martin-Logan, Celestion, Vandersteen, Acarian Alon, and dozens of others. This is not to say that everyone loves all of these brands --- some people love them, some people hate them, and you should listen for yourself --- but most people on the audio newsgroups would rate most of these brands above Bose. Some brands names generally considered worse than, equal to, or at least not consistently superior to Bose include Polk, Klipsch, Sony, Kenwood, KLH, Pioneer, Cerwin-Vega, Advent, DCM, and dozens of others. Of course, again, opinions vary (Klipsch, in particular, has some strong proponents). Given the long list of worse speakers on the market, its actually rather surprising that only Bose receives such criticism on the audio newsgroups. Boston Acoustics and AR have produced some excellent budget speakers in the past, as well as many mediocre speakers; I have heard nothing about the performance of recent models. 3.) Bose Marketing ^^^^^^^^^^^^^^^^^^ One of the issues used both for and against Bose is their marketing. In the loudspeaker arena, Bose has perhaps the largest and most effective marketing campaign of any manufacturer. What other speaker manufacturer runs television ads? The marketing budget is spent in several ways: *Advertising. Part of the marketing budget is spent on advertising and obtaining positive reviews, so that consumers will know and feel favorable towards Bose products before they ever even enter a store. A recent survey in the Denver area showed that most people who purchased stereo equipment had already make up their minds about which brands to purchase well before they actually auditioned any equipment! Many personal anecdotes on the audio newsgroups support this conclusion. The fact that Bose speakers have such an excellent reputation in among the general public is partly a testament to their excellent marketing. *Sales Incentives. In many cases, the store and the salesperson earn higher commissions from selling Bose speakers than from selling other equally priced speaker. Of course, in other cases, the store may have greater incentives to sell other speakers, but Bose is well above average among mass-market speakers. *Store Support. The marketing budget also pays for large numbers of marketers who work with the individual stores, encouraging stores to stock and sell Bose products, and arranging in-store promotions and sales. If the experience of some on the audio newsgroups is to be believed, Bose even sends marketers to the stores to pose as salespeople, who steer customers towards Bose under this guise. These sorts of modern marketing techniques are, for the most part, only to be expected from a large and savvy corporation. Of course, the company with the best marketing does not always offer the best products, although truly unappealing products will fail regardless of marketing. 4.) Bose Research ^^^^^^^^^^^^^^^^^ One point often made in favor of Bose is their research. Indeed, Bose has a large and highly-trained scientific research staff. However, it seems that relatively little of this research filters down to their everyday speakers --- their basic speaker designs have remained largely the same for many years. This rather surprising conclusion is supported by comparisons with other industries. For example, Budweiser and MacDonalds also have large and highly-trained scientific research staffs, and yet continue to produce the same products year after year. In essence, most of the research is for purposes of hedging their bets and flexibility --- if the marketplace demands changes, the corporation will have the research results in hand to react quickly. In the case of Bose, the research budget is still quite small compared to the marketing budget. Furthermore, the research makes good PR, and in fact justifies one of their well known marketing slogans --- "Better Sound Through Research." 5.) Bose Innovations ^^^^^^^^^^^^^^^^^^^^ Bose has the reputation among the general public as a leader in innovative speaker design. This is partly the result of their marketing campaign, but also simply because they are unusual --- its sometimes easy to confuse unusual with new or innovative. However, according to the historically knowledgeble on the newsgroups, most of the Bose's "innovations" were actually devised years ago and incorporated into textbooks and commercial speaker designs pre-dating Bose by years and even decades. In some cases, Bose's patents are small refinements of long-established techniques. Thus, according to many on the newsgroups, Bose's main contribution is popularizing their speaker designs through aggressive marketing. 6.) Bose Engineering and Design ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ There has been much discussion among the technically minded about the engineering/design aspects of Bose. This discussion can get highly technical, and those without the appropriate background may often be left not knowing who to believe. Without getting too heavily into the technical details, this section attempts to summarize these debates. One of the most popular Bose product lines is the AM series of satellite/woofers. About this product line, John Busenitz says: "The problems with the Bose AM systems are many. The woofers are too small to reproduce low frequencies at decent levels. In fact, a review in a recent Stereo Review noted this, saying that the response rolled of at around 36 dB below mid-50 Hz. The small enclosure and high order response are indicative of bad transient response/excessive group delay, which is evidenced by a simple listening test. There is a big upper bass peak, and the bass is boomy and muddy, IMHO. Also the LP filter is too high, and thus the bass module is directional." "The crossover must be high, since the 2.5" drivers in the cubes are much too small to reproduce upper bass to almost any degree of satisfaction, while they are too large for high frequencies, where they "beam" and become directional. And, incidentally, don't have close to a 20 kHz bandwidth." To be fair, many of the same criticisms can be leveled at many or even most satellite-woofer systems. Such systems are popular right now because of their modest space requirements. Their theoretical basis is that low bass frequencies are not directional, so you can put the bass module anywhere in the room, even hide it, and it will still sound as if the bass is coming from the tiny satellite speakers. Unfortunately, as John says, in practice, most bass modules usually go too high in frequency, so that the resulting bass *is* directional. Then the bass will appear to come from a different location unless very carefully positioned relative to the satellites. Furthermore, as John says, the quality of the bass produced by the bass modules is often of questionable quality. As always, listen for yourself. Now we turn to Bose's other speakers lines, especially their 701s/901s. In this line, everyone agrees that Bose speakers employ a highly unusual design. Depending on your point of view, you may say that this design is unusual because it is innovative and patented, or you may say that it is unusual because few others care to duplicate it. Regardless, there are few other speakers with similar designs, and certainly none with anything like the high profile of Bose speakers. One aspect is the "direct/reflecting" design. In other words, they have numerous speaker elements, some angled forwards, and some angled backwards, and some angled to the side. In most speakers, there are only two or three speaker elements, all pointed straight forward. The Bose philosophy is to create a great deal of indirect sound --- sound that reflects off walls and furniture before it reaches the listener. Of course, all speakers inevitably create some degree of indirect sound, unless listened to in a specially treated non-reflective room, but Bose purposely creates a great deal more indirect sound. Some people feel that this strategy results in an unfocused diffuse sound, with unnaturally large stereo images, while others very much like this sound. You should listen for yourself. To justify the direct/reflecting technique, Bose has claimed that, in real life, about 8/9 of sound reflects before reaching the listener, and only 1/9 reaches the listener directly. However, these numbers come from one set of measurements made in a concert hall, certainly an unusually reverberant environment. Furthermore, in practice, the recording picks up both the direct and reflected sounds, and adding more reflection at playback just adds synthetic reflections on top of real reflections. In fact, according to the scientists on the audio newsgroups, there are some well-established theories about the proper ratio of direct to reflected sound --- based on many years of research rather than one perhaps misleading measurement --- which theories Bose speakers intentionally violate. (If you really want to bring out the ambient reflected qualities of recorded sound, a better technique might be surround sound, where it possible to control the amounts of direct and indirect sounds. The proper use of surround sound could fill another entire FAQ.) Before purchasing a Bose "direct/reflecting" speaker, especially one of their more expensive models, you may wish to compare them with other speakers which produce relatively large amounts of indirect sound -- this includes any planar speaker such as Magnepan, Quad, or Martin-Logan. Another aspect to the Bose design is their use of multiple small speaker elements for reproducing bass. While most speakers use just one large high-quality expensive element for the bass frequencies, Bose speakers such as the 901s use many smaller lower-quality less-expensive speaker elements, wired together with complex circuitry. While this certainly produces bass, many people feel that the deep bass is attenuated, and that whatever bass there is contains large amounts of nonlinear distortion. Of course, others think the bass is deep and of high-quality. Whichever way your opinions run, it should be noted that there are well-established theories about the size of the driver versus its lower frequency limit --- the bigger the driver the lower the frequencies it can naturally reproduce --- which Bose violates, or at least tries to circumvent in a highly debatable fashion. More specifically, John Busenitz says: "When judging low frequency response, it is not only the total surface area that is important, but the excursion capability of the drivers and their resonant frequency, which determines the low frequency cutoff. Smaller drivers almost always have far less excursion capability and higher resonances than larger drivers. That is why Bose is pretty much alone in using multiple small drivers." 7.) Bose Popularity ^^^^^^^^^^^^^^^^^^^ Perhaps the most often repeated argument in favor of Bose is their popularity and commercial success. Bose is indeed one of the most popular speaker companies by any measure. Part of this is related to their effective marketing department. More importantly, Bose is indeed better sounding than many of its natural competitors. Despite their dominance in electronics, the Japanese mass-market companies have never managed to capture the full essence of speaker design and manufacture, despite many attempts. Even in Japan, US and other foreign speakers brands are surprisingly popular. Many first time buyers choose electronics by Sony, Pioneer, Techniques, Kenwood, etc., and simply assume that their speakers are of similar quality. Even worse, many people buy rack systems, in which the speaker is inevitably the weakest link, however large their size and however high the number of drivers and however impressive the frequency response curve printed on the plate on the front. In comparison to most Japanese mass-market speakers, Bose speakers are indeed a substantial improvement. In fact, since most appliance/T.V./stereo retailers (Circuit City, Best Buy, Sears, Wards, ...) mainly carry Japanese brands, Bose may be the best speaker available if one restricts oneself to such stores. Furthermore, even in the cases where a store carries better brands, their set-up is often not conducive to fine judgement calls. The speakers are placed cheek-to-jowl, and are all connected through central switcher of marginal quality, and on and on, as described below. In other words, Bose's popularity can be ascribed to many other factors besides sound quality. In general, the short answer to the popularity argument is that popularity does NOT necessarily equate to quality --- just think of popular music such as "New Kids on the Block," popular fast-food restaurants, popular fashions from years gone by such as polyester leisure suits, and popular television programs such as "Full House." There are so many other factors which influence popularity besides quality that it is hardly a reliable indicator. 8.) Bose Repairs ^^^^^^^^^^^^^^^^^ One point made in Bose's favor is the quality of their customer service. Indeed, Bose can offer excellent customer service and repairs. Of course, so can any number of other large manufacturers, such as Radio Shack, Infinity, and so forth. Small manufacturers can offer a personal touch often lacking from large manufacturers. However, their service is not necessarily as consistent, and they may not always survive in the competitive marketplace, in which case, of course, their customer service is no longer available. These are all part of the well-known trade-offs between large established companies and smaller companies. It should also be pointed out that it is usually possible to repair speakers even if the company folds. Most speakers are constructed from standard parts which are readily available. It should also be pointed out that, unless abused, speakers are fairly reliable. The most common source of damage to speakers is an under-powered amp, which can clip at high-volume levels, ruining the tweeters. Less commonly, a speaker may be damaged by too much sustained power, or a malfunctioning amp. However, aside from clipping, probably the most common source of speaker failure is the rotting of the foam surround, which occurs over 5-15 years. A surround is A flexible membrane encircling a speaker cone. Rotting can be avoided by using other materials, such as butyl rubber, instead of foam. However, many mass-market speakers, including Bose, employ foam surrounds, albeit with chemicals intended to inhibit rot. 9.) Newsgroup Opinions on Bose ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ One issue brought up by certain Bose supporters is the nature of the participants in the audio newsgroups. In particular, one or two have claimed that everyone on the audio newsgroups is an "audiophile," while implying that this is a very bad thing. Beside casting aspersions on audiophiles, these assertions also ignore the fact that the audio newsgroups (exceping rec.audio.high-end) are generally *not* heavily populated by audiophiles and, indeed, are often quite hostile to audiophiles in certain regards. In fact, besides the Bose issue, debates between audiophiles and non-audiophiles are the most common and heated discussions on the audio newsgroups. For those not familiar with this debate, a little background is in order. As their basic philosophy, "audiophiles" hold that personal listening must hold precedence over all other factors. In particular, they believe that careful extended listening can reveal important details which are missed by current measurements and blind testing procedures. Many non-audiophiles take exception to this. Indeed, there is a great body of evidence that the human hearing system is highly fallible, and easily influenced by things other than sound quality itself, so that only controlled rigorous blind tests yield generally useful results. Many non-audiophiles also say that today's measurement technology can give an extremely complete profile of sound quality. Finally, many non-audiophiles express incredulity at some of the expensive equipment touted in certain audiophile circles, especially tweaks such as exotic cables, CD coatings, vibration control devices, and so forth. This FAQ has made an effort to represent both points of view throughout the text, since both sides have merit. There are even many people who hold both views, to the extent they do not conflict. Despite their vigorous disagreement on many other topics, Bose is a topic about which both factions agree --- both factions tend to be strongly skeptical of Bose. The engineers believe they have the measurements, the blind listening test results, and the theoretical and technical arguments to prove that Bose products have serious drawbacks, while audiophiles think that Bose speakers simply sound much worse than a large number of other less costly speakers. 10.) Magazines and Bose ^^^^^^^^^^^^^^^^^^^^^^^ New comers to the audio newsgroups may wonder why the opinions expressed here are so different from everything they've heard before. In particular, they may wonder how Bose could receive such positive reviews if their products are as poor as many people claim. The first point is that Bose has certainly received its fair share of negative reviews. Furthermore, many of the more ambitious magazines simply ignore Bose products. Finally, the US publications which regularly feature Bose may not always have the most proper or stringent standards. The purpose of this section is to describe the various major publications, to explain why their judgements may or may not be reliable, and to point the reader to major magazines other than those they currently rely on. The five major US publications which review stereo equipment are Consumers Reports, Stereo Review, Audio, Stereophile, and The Absolute Sound. The first two concern mainly mass-market equipment, the last two concern mainly "audiophile" equipment, while Audio magazine attempts to cover both markets. In many ways, none of these publications is entirely satisfactory. A brief critique of each follows: *Consumers Reports. They assess speakers using measurements and, to a lesser extent, blind listening tests. Their standards and testing procedures were designed many years ago, and are widely considered out-of-date and inadequate. In fact, after they negatively reviewed a Bose speaker, Bose sued Consumers Reports on the grounds that their testing procedures were faulty. While Bose lost the suit, it was on other grounds, and not necessarily because they failed to prove the faults in CR's testing procedures. (Interestingly, Bose speakers have tended to rate quite well in Consumers Reports ever since.) A common opinion on the audio newsgroups is that Consumers Reports' speaker ratings are actually *inverse* to quality. In other words, the better speakers rate lowest, and the worst speakers rate highest. You should listen for yourself and decide. *Stereo Review. Stereo Review is widely considered an advertising format by those on the audio newsgroups. Annual subscriptions are available for very low prices, presumably subsidized by advertising revenues. As a matter of editorial policy, you will *never* see a bad review in Stereo Review. They claim that if they can't say anything good, its better to simply say nothing at all. However, they do give many people the impression that they will positively review almost any product from any advertiser. Assuming that they review products that they would not personally endorse, some people feel that they can intuit the reviewer's true feelings by reading between the lines, magnifying the gentlest criticisms to mean that the reviewer actually despises the piece in question. The joke is that a typical Stereo Review article concludes with "it has a handsome polished oak finish and, of all the speakers I have ever reviewed, this is certainly one of them." While non-judgemental people have their place, non-judgemental audio magazines have a more limited usefulness. *Audio. At one time, Audio was not that much different than Stereo Review. However, in recent years they have made an effort to beef up their content, and to improve their staff quality. While they may not feature many negative reviews, their style gives many the impression that their reviewers still have certain standards. *Stereophile. An "audiophile" magazine. Their reviews are usually based on unscientific listening tests done by one reviewer, although they occasionally conduct blind listening tests, and they always provide fairly good measurements for those technically minded enough to interpret them. Many on the audio newsgroups are put off by the paucity of scientific listening tests, and their espousal of sometimes outrageously expensive equipment ($2000 is sometimes cheap in this world) including various oddball "tweaks." At the very least, their reviews should be taken with a grain of salt, and the reader must take a good deal of effort to ensure that their tastes match those of the reviewers. Stereophile publishes a useful list of recommended components in the April and October issues. It is unlikely that a Bose product would ever be reviewed by Stereophile. *The Absolute Sound. Another "audiophile" magazine. Provides an alternative to Stereophile, while taking the same general philosophy, except even more purist and (depending on your point of view) extreme. No measurements or blind testing. It is unlikely that a Bose product would ever be reviewed by TAS. There are, of course, many smaller US publications as well as numerous foreign publications, especially British, which are beyond the scope of this FAQ. 11.) Bose and Litigation ^^^^^^^^^^^^^^^^^^^^^^^^ Like many large corporations, Bose has sometimes taken legal action to protect its reputation and patents. In some cases, this can be seen as the dark side to their marketing efforts --- not only do they disseminate positive information about Bose, by they also attack sources of negative information, as well as other speaker manufacturers. Besides suing Consumers Reports for their negative review, as mentioned in the last section, some other instances cited on the newsgroups include: *Bose sued Theil to prevent them from naming their speakers with a .2, since Bose also named their speakers with a .2, and Bose felt that this might lead consumers to confuse Bose with Theil. *Bose sued Speaker Builder magazine for publishing the specifications of a bandpass enclosure that Bose claimed infringed on their patents. *Bose sued Cambridge Sound Works for their claim that they offered "Better Sound Than Bose For Half the Price." Bose also claimed that some of Cambridge's speakers resembled Bose speakers. (For the record, the newsgroup participants generally rate Cambridge ahead of Bose.) *In the example that hits closest to home, after a student posted negative opinions about Bose on the internet, Bose wrote a letter of complaint and, as a result, the student was called before the Dean. 12.) An Aside ^^^^^^^^^^^^^ At this point, the FAQ has summarized most of the points raised endlessly for and against Bose. While you can read about Bose till doomsday, one listen is worth a thousand words. The remainder of this FAQ will explain how to go about listening and deciding on the merits of Bose for yourself. This is generic advice which applies equally well to any speaker brand. While the next two sections are generic, and do not address Bose specifically, they are included in this FAQ for the following reasons: *They rebut certain claims made in support of Bose. In particular, these two sections rebut the claim that most Bose purchasers make carefully informed decisions --- it seems highly unlikely that most Bose purchasers, or most purchasers of any speaker brand, have followed the demo procedures and principles outlined below. *Without these two sections, readers may run off to the local appliance/T.V./stereo shop, compare Bose to obviously inferior speakers, in conditions which do not allow for meaningful comparisons, and conclude that Bose is indeed the best speaker on the market for the money. While Bose may be a superior product, its important to base such conclusions on a sound foundation. *These two sections are aimed especially at readers who have already listened to Bose, and feel that their personal experiences have already definitively proven Bose's superiority. Hopefully, these sections will indicate some ways that your experiences may have mislead you. In other words, even if you think you *know* that Bose speakers --- or any other speaker brand for that matter --- are the best, these two sections may give you pause. Hopefully, it will inspire a few of you to reconsider your opinions, even if you ultimately decide that you were right in the first place. 13.) How to Listen to Bose ^^^^^^^^^^^^^^^^^^^^^^^^^^ Listening is key, and this section will provide a few pointers on how to listen correctly and effectively. To begin with, it helps to be aware of human psychology and how this can bias your perceptions. Some of these include: *Expectations. If you expect Bose to sound good, it is likely to sound good. Visa versa, if you expect Bose to sound bad, it is likely to sound bad. Try to keep an open mind. Better yet, try to compare speakers without knowing which brands you are listening to. In this sense, the less you know about the speaker you're listening to, the better. *Second Speaker Sounds Best. In a comparison of two items, people tend to prefer the second item. This is one of the bases of the Pepsi challenge --- present the Pepsi second. This effect is sometimes used by dealers to favor a specific speaker. *The Louder Speaker Sounds Best. In a comparison of two speakers, people to to prefer the louder one. Of course, this is not true if the loudness difference is large. However, small differences in loudness are not perceived as differences in loudness --- rather the louder speaker is perceived as better. This effect is sometimes used by dealers to favor a specific speaker. This effect can be minimized by demoing speakers at a variety of different volumes --- fiddle with the volume control! *The Speaker with more Bass and Treble Sounds Better. In a comparison of two speakers, people tend to prefer the one with more bass and treble. Again, like loudness, slight differences are not perceived as due to frequency response differences --- the increase in bass and treble is perceived as better. While increased bass and treble sound better in the short run, it can become extremely fatiguing in the long term. Many speaker manufacturers build a slight contour into their speakers to help them perform well in short casual demos, but the purchaser drawn in by this technique often lives to regret their decision. This effect is also sometimes used by dealers to favor a specific speaker. Playing with the bass and treble controls, and varying the volume (perceived frequency balance changes with volume), can help overcome this effect. If you find that, for some reason, you actually prefer increased bass and treble, most receivers have a loudness switch, and bass and treble controls, which accomplish the same thing. However, if the bass and treble boosts are built into the speakers, it is nearly impossible to cancel them exactly using bass and treble controls if you later find them tiresome. *Room placement. The sound of a speaker is greatly influenced by its location in the room, and its interactions with a room's acoustics. The sound is also influenced by listener position and listener height. For example, most speakers sound best if the tweeter is at the same height as the listener's ears, or slightly lower. *Mood. In particular, it is very hard to judge when nervous or under pressure. *Other factors. Color, size, styling, lighting, etc. can affect your judgements. I have even heard of dealers using small surround sound speakers --- used properly, listeners will not perceive the additional separate speakers, but will instead perceive the main speakers as better. The only way to ensure a completely neutral assessment is a double-blind test, where neither the listener nor the conductor of the test knows which speaker is being heard. Unfortunately, a proper double-blind test is out the realm of possibility in most cases. To summarize, while most dealers are honest, a few use human psychology to push specific speakers, the ones which earn them the most money, or perhaps speakers that the salesperson honestly prefers, although their tastes may vary from yours. Even when a dealer is not purposely trying to bias the customer towards a particular speaker, its possible and likely for non-sonic aspects to greatly influence judgements of sound quality. Being aware of possible bias factors, as listed above, can save you from making some common mistakes. When auditioning speakers, its vital that you be familiar with the music. In other words, BRING YOUR OWN MUSIC. If you allow the dealer to choose the audition music, they may choose music which flatters the speakers in question. At the very least, if the dealer uses unfamiliar discs, you will have no idea what the music should sound like, and thus you will have no way to distinguish the sound quality of the disc from the sound quality of the speakers. For myself, I try to bring one or two really good sounding CDs to test for the ultimate capabilities of the speakers --- but don't be surprised if CDs that sound good on your current speakers turn out to be mediocre on better speakers, and that CDs which sound mediocre on low quality speakers turn out to sound excellent on high quality speakers. In other words, if you've never heard your CDs on first-rate speakers, don't be surprised if your sonic judgements change as you hear them on more and more speakers. I also try to bring several CDs with known sonic flaws --- harsh treble, slight distortion on loud passages, tape hiss, maybe even some 78 transfers with surface noise ---- to see whether the speaker exposes those flaws, while still bringing out the better features of the music, so that overall sound is still enjoyable. You might also want to bring a CD containing lots of low frequencies, such as pipe organ music, to test the low frequency behavior of the speaker. The biggest flaw with most speakers, especially small or less expensive speakers, is either a lack of low bass or a poor quality low bass, in that the bass has a one-note thumping quality, instead of a continuous range of well-defined bass frequencies. If you can't afford the cost or room for a speaker with true high-quality deep bass, you need to determine whether the bass response is satisfactory on the types of music you listen to most often. Having established some common pitfalls, now let us describe the proper set-up for listening. *Placement. The speakers should be placed well away from walls and other speakers. Any nearby object or surface can affect the sound quality of a speaker. This is especially critical in terms of bass response --- speakers near walls or, especially, in corners will have more bass, although the quality of the bass can be worse, since the bass is reinforced at some frequencies and canceled at others, resulting in a very uneven bass response. (Of course, when it comes to bass, some people prefer enormous quantities to quality, and I wish those people would stop driving by my house.) *The best demos are relaxed, preferably in familiar surroundings, such as your own home. *Leave plenty of time. First impression are often wrong. Any change in sound is often perceived as an improvement at first, and only extended listening will tell for sure if the change is for the better, the worse, or just different *The speakers should be hooked up separately --- they should *not* be wired through a main switcher box. With more than two or three switches, most commercial switcher boxes are notoriously poor in sound quality, and will tend to make all speakers sound much worse than they should, and may obscure important differences between speakers. The store can use a *high-quality* switch between two or three speakers for the purposes of blind testing, but this is quite rare. If a store complains that its too much trouble to wire the speakers individually, there are other stores which do. I've seen stores tediously and methodically disconnect and remove one set of speakers, and connect a second set of speakers, so that the two speakers are compared using the exact same system and in the exact same location. 14.) How to Choose a Bose Dealer ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Besides offering demo conditions such as those listed above, here are some other things to look for in a store and its salespeople. * The staff should NOT employ high-pressure sales tactics. Some examples of high-pressure tactics include: sales which end tomorrow; special manager approved discounts which are only good if you purchase right away; excessive badmouthing of certain products; excessive praise of certain products; completely controlling the volume, music, and other conditions in the listening demo; staff is too solicitous, so that the salesman never stops talking or never leaves you alone; the list goes on and on. * The staff person should be able to explain a speaker's design philosophy briefly and in easy-to-understand terms, but they should not use design or features as the main selling point --- after size and price constraints have been established, a speaker's sound quality should be its main selling point. There are many ways to successfully design a good loudspeaker, each with its advantages and disadvantages, and there is no one correct or superior design. Many people will buy a speaker based solely on which one has the best "story" about its design and features. * The store should carry a wide price range. Listening to more expensive speakers helps you to understand what high-quality speakers should sound like, so that you know what to look for even among less expensive speakers. * The store should use better quality electronics in their demos. This includes brand names such as Adcom, B&K, Rotel, and harman-kardon. Even if you choose to use a budget receiver in your own system, better electronics will reveal the ultimate capabilities of the speakers, in case you decide to upgrade someday. In any event, you do not wish to penalize a speaker for simply accurately reporting the poor quality of the receiver or CD player used in the demo. Of course, on the other hand, you do not want to choose a speaker which accentuates or exaggerates problems with other components. Different speakers may sound better with different receivers, and the store should be competent enough to choose a good match. If you're seriously considering purchasing a speaker, you should try to audition it with the rest of your system, and in your room, to make sure they're compatible. In most cases, these conditions are found only at dedicated stereo stores. While one might expect to pay extra for the extra service, these stores generally carry speakers starting for around $150-200, or only slightly higher than cheapest speakers in mass-market stores. Of course, they may also carry speakers well into the $1000s. For best service, visit the store at off-peak hours, when the sales staff is relaxed and can afford to spend some time explaining and demoing. The mass-market applicance/T.V./stereo stores usually do not have adequate demo facilities and, perhaps as a direct result, tend not to carry the better speaker brands, since differences in sound are rarely audible under the circumstances. Rather than using sound quality, appliance/T.V./stereo stores tend to sell speakers in the same way as appliances --- they stress brand name, price, sales and promotions, advertising, salesperson recommendations (their salespeople often lack a deep knowledge of stereo, or are not candid about their opinions), and features. Unfortunately, lacking adequate local dealers, many people will be unable to demo speakers under the proper conditions. In this case, you may have to rely largely on recommendations. At the very least, hopefully these last two sections have given you some basis for assessing the credibility of any recommendations. If you must buy your speakers without a proper demo, make sure to get a money back guarantee.
  8. Maak er dan maar de zaterdagochtendliefhebbers van Appelscha Vooruit van. Om 9 uur de aftrap en om 11 uur aan het bier. Voor de derde helft, zeg maar.... Het moet gewoon leuk blijven. Maar op dit forum word je soms ineens voor gekke Henkie uitgemaakt als dezelfden steeds weer lont ruiken. Wat heb ik verkeerd gedaan? Ik probeer gewoon iets leuks te vertellen. Wie heb ik beledigd? Ik snap ok wel eens niet alles wat iemand vertelt. Dat verklaar ik het toch ook niet ineens voor onzin? Zie je het verschil? Speel op de bal en niet op de man. Aub zeg........ Wat is er nou leuk aan om steeds weer mensen te beledingen op zo'n forum? Noem je dat hobby?
  9. Die vind ik echt grappig. Als ik het met mijn vingers in dat HFC verzamelboekje aanwijs (het klopt echt overal) dan begrijp je het ook. Ook van die zijbanden op de piek van de spectrumanalyzer. Ik ben geen electronicus, maar ben wel op de hoogte van een flink aantal zaken die ik van anderen heb overgenomen, oa deze twee facetten. Maar dan hoef ik nog niet voor linke loetje te worden uitgemaakt... Valt best mee hoor.
  10. Nou, een mooie heeft een lekker steile oploop. Dan liefst geen afronding naar het horizontale stuk. Geen overshoot. Dus niet te veel doorschieten. En dan ook geen rimpel op het platte dak. Dat zijn de betere. Nogmaals : Als ik fout zit, dan zit de redactie van een review- verzamelboekje van een internationaal gerespecteerd audioblad ook fout. Het maakt me eigenlijk ook niks uit. Het moet leuk blijven....
  11. Waarom gneuzel? Als je met vooroorlogse technologie aankomt, mag niemand daar dan wat van zeggen? Kan je van een starre achteras wegligging verwachten? Kom toch eens bij zinnen zeg. En donder die rotzooi gewoon de winkel uit. Kom ervoor uit dat je daar rotzooi hebt staan. Word eens volwassen....
  12. Je hebt een kans gemist om jezelf een afgang te besparen. Echt waar joh? Wabblief? Mag ik het nu eens niet snappe? Het klopt bij elk element hoor... http://www.audioxpress.com/reviews/media/104hansen2284.pdf Figuur 2: blokgof. Fig 5. Spectrumanalyse. figuur 2 is dus het omgekeerde bvan de freq. kar. , maar dan alleen het begin heeh? En op de flanken van fig 5 : tweemaal de res. piek bij lage frequenties. Klopt gewoon allebei. Echt waar. Geen afgang hoor. Wil je dat graag? Mij best hoor. Scheelt me niks. Kan me dat nou verrotte...
  13. Hier weer zoiets, nota bene hetz. element. Met freq. karakteristiek erbij, verhipt zeg. http://www.enjoythemusic.com/magazine/equi.../dynavector.htm Het rechter eind van de frequ. kar zie je terug, omgekeerd aan het begin van de blokgolf. Heeeeeee. Nou moe. Bij slechtere elementen is het duidelijker. Je ziet de rondheid van de kont en de hoogreson. beide terug in de stijgkant van de piek. Het klopt niet andersom: basbereik en slotfase van de blokgolf . Dat niet . Gek . Maar echt waar. Serieus.
  14. Yip. Hier heb je drie blokvormen:dat is dus het onderwerp waar ik over begon: blokvorm en freq. karakt. http://www.dynavector.co.jp/english/etechn...dispersion.html De bron zie je links boven. Zit in de groef. Links onder output van een watje. De dweil laat het volume veel te traag oplopen: geen stijdsnelheid. Shit dus. Dan gaat hij in een royale bocht naar rechts. Het inputsignaal is allang nul. Maar de oen voelt nattigheid keert het lijntje laks een beetje mee. Komt laat op nivo uit. Rechts onder de plaatselijke favoriet. Fluvx omhoog. Remt abrubt af. Ho. Ik moet naar rechts. Beetje overshooten: schiet ik te ver door onhoog? nee, niet zo erg Gauw de vlakke top nabootsen ,dus snel rechtsom. Braaf. Kijk je anders naar de onderste twee krommen en draai je ze in gedachten om, dan zal je als je de freq'kromme daar mee vergelijkt zeggen: verhipt, bijna eender.
  15. Heb je echt nooit zo'n blokgolf van een element gezien? Misschien kan ik eens gaan www-en of ik zoiets kan vineden voor je. Als dat helpt...
  16. Wat bedoel je precies? Tot hier heb ik je verhaal gelezen en niet verder, want ik heb het gevoel dat er bij mij iets mist. Volgens mij zou je op een "scope" een sinus moeten zien, of heb jij een ander apparaat in gedachten? Als je mij het theoretische bewijs van die gespiegelde hobbeldebobbel kunt geven, ben ik je zeer dankbaar. P.S. als je lid wordt van de AES, kun je nog veel meer downloaden tegen een gereduceerd tarief. Groet, Jacco Nee, theoretisch moet je een speld zien. Horizontaal frequentie. Vertikaal de amplitude. Het is ideaal gezien een supersmalle piek. Snel stijgen naar max, direct af naar nul. In de praktijk laat de scope van een enkele toon een smalle steile heuvel zien. Maar met op elk van de twee flanken een extra piek: de weergave van de rf. Die uit zich in rf: afstand tot hoofdpiek duidt exact de rf aan: bijv plus en min 8. En in vertikale zin zie je de piekamplitude. Is die nul, dan zie je zowat geen zijpiek. Is de peikamplitude hoog, dan kan de zijpiek gaan concurreren nmet het hoogste punt van de hoofdpiek. het klopt echt hoor. Ook bij het verband tussen aanzet van blokgolf en kont van frequentiekarakteristiek. Ik ben gekke henkie niet. LOL. En het HFChoice- blad geeft ook geen theor. bewijs. Maar het klopt wel, bij alle elementen. Is dat al niet genoeg? Ik heb geen geld voor het lidmaatschap van de AES. Zou minstens mijn jaarlijkse hobbybudget betekenen. Met studerende kinderen: Onmogelijk.
  17. Laat die uitleg maar zitten. Het is tenslotte je HOBBY. Dat er wartaal staat maakt dan niet zoveel meer uit. Ik wens je nog vele jaren plezier met deze leuke HOBBY. Jij noemt het wartaal. en ik kan het niet helpen als je misschien niet de opleiding hebt om vrij simpele grafieken te begrijpen. Heb je weleens een frequentiekarakteristiek gezien? Je kan kennis van iemand die er meer verstand van heeft toch geen wartaal noemen? Dat zeg ik toch ook niet van iemand die er nog meer van weet dan ik? Ik vind het niet erg hoor. Maar je probeert jezelf een oordeel aan te matigen waar je niet eens toe in staat bent. Kijk, ik doe het alleen maar om iemand verder te helpen....
  18. Ja, dat weten we inmiddels wel Voor de rest van je verhaal, en ik ben er van overtuigd dat je het in alle ernst hebt geschreven, moet ik even glimlachen. Jij vergelijkt dus een logaritmische schaal (frequentie karakteristiek of beter de amplitude overdracht in het Bode diagram) met het inschakelverschijnsel in het tijddomein dat een lineaire schaal is. Wat niet wegneemt dat er wel iets van waarheid in zit als je stelt dat een beperkte bandbreedte een (af)rondend effect heeft op het "platliggen" van die ingeschakelde blok. Dat platliggen kan overigens ook een wat overdreven steil oplopen zijn als er nulpunten aanwezig zijn. Dat verhaal met die auto en een lange danwel korte weg kan ik nog steeds niet goed plaatsten. Groet, Jacco Het gaat er niet om of de weg lang of kort is. De weg en de drempel vergelijk ik met een grafiek. De weg is een horizontele lijn. Die trek je van links naar rechts. Hoe verder je naar rechts komt, hoe later het is. Maar je kunt op die weg allerlei vormen van drempels tekenen. de hoogte van een drempel is het geluidsniveau. Als je auto dus omhoog gaat wordt het tegelijkertijd later, maar het volume neemt ook toe. Dus omhoog is harder geluid. Hoger is harder. Ik beschrijf het karakter van een grafiek. Lijn naar rechts, daaraan een lijn omhoog, dan een lijn naar rechts( aansluitend aan elkaar) dan omlaag tot oorspronkelijke hoogte en dan weer naar rechts: blokvorm. Een ferquentiekarakteristiek lijkt daarop. Omhoog is het volume dat toeneemt. Naar rechts neemt echter niet de tijd toe maar de frequentie. Bij een schuine lijn naar rechts boven neemt in het eerste geval tijd en volume toe en in het geval van de frequentiekromme de frequentie en het volume.
  19. Ja, dat weten we inmiddels wel Voor de rest van je verhaal, en ik ben er van overtuigd dat je het in alle ernst hebt geschreven, moet ik even glimlachen. Jij vergelijkt dus een logaritmische schaal (frequentie karakteristiek of beter de amplitude overdracht in het Bode diagram) met het inschakelverschijnsel in het tijddomein dat een lineaire schaal is. Wat niet wegneemt dat er wel iets van waarheid in zit als je stelt dat een beperkte bandbreedte een (af)rondend effect heeft op het "platliggen" van die ingeschakelde blok. Dat platliggen kan overigens ook een wat overdreven steil oplopen zijn als er nulpunten aanwezig zijn. Dat verhaal met die auto en een lange danwel korte weg kan ik nog steeds niet goed plaatsten. Groet, Jacco Het klopt echt hoor. Het maakt niet uit of een of beide schalen lineair is of logarithmisch. Trouwens, de redactie van dat boekje kwam ermee hoor. Dus ikzelf was er nooit opgekomen. Ik heb in 2 of drie van die boekjes dit facet nagegaan bij tientallen reviews , en overal klopte het perfect. Wat ook heel grappig is: een toon die vanaf een element komt is nooit een zuivere smalle piek op de scope. De resonantiefrequentie is merkwaardig genoeg rechts en links op de flanken van de driehoekige scope- grafiek te zien. Een hogere resonantiefrequentie plaatst de piek ervan verder van de hoofd- piek af. Dus hij zakt ook verder langs de helling naar onderen. Een hoger q- factor doet de piek van zo'n zijband omhoog rijzen. Dus: zowel een lagere res. frequentie als een hogere piekfactor geeft 2 stuks gemenere inbreuken op de zuiverheid van een enkele toon. Het kan best zijn dat een enthousiaste gebruiker dat omschrijft als dynamiek: ja de toon klinkt misschien feller en minder vierkant. De zijbanden zijn in ieder geval minder hinderlijk. Ziehier twee leuke facetten van de diverse grafieken in elektro- akoestiek- land. Theoretische achtergronden zijn al decennia lang een hobby van me. Ik heb van iemand een paar maanden geleden een grote stapel copieen gekregen van artikelen op AES- niveau. de man had toegang tot een ruime bibliotheek . Voordat ik goed door die stapel heen ben is het zeker een jaar verder. Hifi en zo is echt een wetenswaardige hobby.
  20. Sorry, maar ik begrijp hier niets van. Wat wil je nu precies vertellen? Groet, Jacco Ik probeer een begrijpbare omschrijving te maken van een paar grafieken die overbekend zijn in de electro- akoestiek. Ik veschrijf wat een blokgolf is. En dan wat een frequentiekarakteristiek is. Iemand wilde weten hoe ik dat verband zag tussen het laatste deel van de frequentiekarakteristiek en het eerste deel van de blokgolf. Ik vergelijk het met een lastige drempel in een straat. Hoe verder je de straat in komt, hoe langer de rit heeft geduurd. Dus de afstand die je op die weg hebt afgelegd stelt ergens ook de horizontale richting voor in de grafiek van een blokgolf. De hoogte van de drempel is dan het geluidsvolume. Bij de frequentie - karakteristiek is de afstand van de weg weer de frequentie: aan het begin laag en aan het eind hogere frequenties. Ze wilden een nadere uitleg endie heb ik zo goed mogelijk gegeven. De vorm van het einde van de ferquentie- karakteristiek zie je telkens precies terug aan het begin van elke blokgolf.
  21. Ik zeg ook niet dat Bose goed spul maakt. Of dat het voor een goeie prijs verkocht wordt. Ik zeg alleen dat Bose geen uitzondering is, en waarschijnlijk niet eens de meest extreme winst maakt binnen de audiowereld. Voorbeeldje: 47Labs verkoopt een GainCard voor
  22. Zie boven. Nauwkeurig lezen wat er staat is toegestaan.
  23. Hoe durven jullie shit als Bose te sorteren? Waarom zouden ze dat niet durven/mogen? Mogen wel. Maar heo kan je de bedragen verantwoorden die Bose vraagt voor zijn vooroorlogse speakertechnologie! Dat is durf. Petje af hoe Mr. Anwar Bose er nog steeds in blijkt te slagen dat soort rubbish de winkels in te marketen. Dat had mij nooit gelukt> Durf . Inderdaad. Veel durf. in zekere zin dus perfect. Ik vind dat Bose het in vergelijking met sommige audiofiele produkten nog niet eens zo heel erg bont maakt. Heb wel eens een houten volumeknop gezien voor meer dan
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