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Loudspeaker timing
Many loudspeakers incorporate some type of time alighnment scheme in
their design such as a sloping baffle. Is this truly necessary? Can people actually perceive the difference in speed between high frequencies and low frequencies? When you listen to a live orchestra do you hear the bass drum before you hear a high from a flute? Can someone explain to me the significance of pace, rhythm, and timing in our audio playback systems Sam |
#2
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Loudspeaker timing
"Sam" wrote in message om... Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Can people actually perceive the difference in speed between high frequencies and low frequencies? When you listen to a live orchestra do you hear the bass drum before you hear a high from a flute? No, you don't. That's the point of time alignment. Can someone explain to me the significance of pace, rhythm, and timing in our audio playback systems Sam Preface: A sloping baffle by itself does not provide time alignment. It must be combined with a 1st order crossover. For example, NEAR 50 speakers, with a sloping baffle, are not time aligned. Argument: It is highly debated. The output of a square pulse as rendered by a time aligned speaker looks like a square pulse. Other designs render it as two or three unrecognizable waveforms, mysteriously percieved by most people to be the same. Many studies claim that the ear is insensitive to time delay. Others claim that the last iota of imaging quality is provided by this method. Yet time alignment exists only if the listener positions himself at one spot in space. The Spica TC-50 and TC-60 were perhaps the first speakers to popularize time alignment. But whether the time alignment, or the 1st order crossover, or the felt covering the baffle, or a combination of all these things is responsible for the image clarity, is subject to debate. Time aligned speakers have low power handling capacity, as a consequence of the 1st order crossover. Hence they are not suitable for listening at greater than moderate volume. |
#3
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Loudspeaker timing
"Brian l. McCarty" wrote in message ws.com... On 29/9/03 14:27, in article , "Sam" wrote: Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Nope. For the theory to be accurate, you'd have to sit in one very precisely measure location, and never move your head even a millimeter. It makes good marketing copy, however. Not true. According to Blauert (http://www.iis.ee.ic.ac.uk/~frank/su.../sl9/main.html), the ear is able to break up the fine structure of the signal for frequencies between 20 and 1600 Hz. At 1600 Hz, the wavlength is about 8 inches, which means that if a listener positions his head within a lateral plus or minus 4 inch range, his ear will percieve a time-coherent signal. Above 1600 Hz, the ear is believed to rely on intensity, ie., "envelope" information for sound localization. It is this observation which inspires the belief that the ear is insensitive to phase information. However, the ear is sensitive, at least for simple pulses, to intra aural time delays as small as 6 microseconds. |
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#5
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Loudspeaker timing
Brian l. McCarty wrote:
On 29/9/03 14:27, in article , "Sam" wrote: Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Nope. For the theory to be accurate, you'd have to sit in one very precisely measure location, and never move your head even a millimeter. It makes good marketing copy, however. Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. I think you have the answer. Time alignment has long been repudiated as speaker designer snake oil. Sir, I just want to say that you are a *jerk*. ;-) Lionel |
#6
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Loudspeaker timing
"Lionel" wrote in message ... Brian l. McCarty wrote: On 29/9/03 14:27, in article , "Sam" wrote: Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Nope. For the theory to be accurate, you'd have to sit in one very precisely measure location, and never move your head even a millimeter. It makes good marketing copy, however. Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. I think you have the answer. Time alignment has long been repudiated as speaker designer snake oil. Sir, I just want to say that you are a *jerk*. ;-) Lionel It's a rare opportunity to address Brian personally. I second Lionel's opinion. You are a *jerk*. |
#7
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Loudspeaker timing
Bob Morein wrote:
"Lionel" wrote in message ... Brian l. McCarty wrote: On 29/9/03 14:27, in article , "Sam" wrote: Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Nope. For the theory to be accurate, you'd have to sit in one very precisely measure location, and never move your head even a millimeter. It makes good marketing copy, however. Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. I think you have the answer. Time alignment has long been repudiated as speaker designer snake oil. Sir, I just want to say that you are a *jerk*. ;-) Lionel It's a rare opportunity to address Brian personally. I second Lionel's opinion. You are a *jerk*. I know it's really mesquin and vain but sometime vengeance is as good as a fresh beer. ;-) |
#8
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Loudspeaker timing
"Sam" wrote in message
om Many loudspeakers incorporate some type of time alignment scheme in their design such as a sloping baffle. Is this truly necessary? No, because the same goal, which is time-alignment of the drivers at the crossover points, can also be accomplished by means design of the of the crossovers. Can people actually perceive the difference in speed between high frequencies and low frequencies? I don't think you are saying what you intended to say. There's no difference in speed between high and low frequencies, but there can be a difference in relative timing of signals. Yes, differences in time alignment can be heard, but at higher frequencies they are mostly heard due to frequency response variations that they cause. If equal-sized signals from the woofer and tweeter aren't time-aligned around the usual crossover point of say, 3 KHz, they won't add up properly to give flat response. When you listen to a live orchestra do you hear the bass drum before you hear a high from a flute? Only if he bass drum plays first! But that's not the problem that stepped or sloped baffles are trying to address. I think you really need to think this through. The bass drum and the flute in an orchestra aren't that well synchronized because the players are usually so far apart. The players are humans and they synchronize to each other based on their hearing, which includes significant delays as sound travels across the stage and as their reflexes take finite amounts of time. The bass drum is usually someplace near the center or left back, while the flute player is closer to the center-right front. The flute player is closer to the listener if the listener is in the center of the room, but if the listener is to the far left, the bass drum player might be closer or at a similar difference. Bottom line, the differences in distance in the concert hall are usually measured in feet, while the differences in distance due to the design of speaker enclosures is probably a foot or less. The speed of sound is basically constant, so the differences in timings due to locations of musicians in the concert hall and the differences in timings due to locations of speaker drivers in enclosures are vastly different. From the standpoint of the microphones that are used to record, there are timing differences measured in many milliseconds among the various instruments in an orchestra. If you look at speaker drivers on a flat baffle board, the timing differences due to mounting the speakers (all within one foot) are probably less than a millisecond. Not to be compared! Can someone explain to me the significance of pace, rhythm, and timing in our audio playback systems Wrong criteria, all of them. See my former comments about smooth, flat frequency response. Ironically sloped and stepped baffles can also add frequency response variations due to effects like diffraction. The idea of time-aligning speakers traces back to sound stages in Hollywood in the 1930s. The monitor speakers of the day were based on horns, and there were path differences between woofers and tweeters, sometimes of many feet. These were due to the differences in the design of the woofers and tweeters. Timing could vary by 3-10 milliseconds or more. Sharp sounds like tap dancing were observed to be undesirably changed and highly colored by those time differences. Because the differences were so gross, they were important concerns. In contrast, consider a modern 2-way speaker with a 8" or smaller woofer and a dome tweeter. The path difference might be 6 inches or less. Timing due to path length differences are less than a millisecond. This is an entirely different kind of perception than those due to timing differences or 5 or 10 milliseconds. |
#10
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Loudspeaker timing
On 29/9/03 19:36, in article , "Arny
Krueger" wrote: I think you really need to think this through. The bass drum and the flute in an orchestra aren't that well synchronized because the players are usually so far apart I think it's YOU that needs to think this through. The bass drum and flute are perfectly synchronized because the players are professionals that are trained to follow not just audio cues but a conductor. Please don't offer opinions in areas you have no competence. Whatever that might be. Bob Morein -- http://www.ledger-enquirer.com/mld/l...ws/4853918.htm Doctoral student takes intellectual property case to Supreme Court By L. STUART DITZEN Philadelphia Inquirer PHILADELPHIA -Even the professors who dismissed him from a doctoral program at Drexel University agreed that Robert Morein was uncommonly smart. They apparently didn't realize that he was uncommonly stubborn too - so much so that he would mount a court fight all the way to the U.S. Supreme Court to challenge his dismissal. The Supremes have already rejected this appeal, btw. "It's a personality trait I have - I'm a tenacious guy," said Morein, a pleasantly eccentric man regarded by friends as an inventive genius. "And we do come to a larger issue here." An "inventive genius" that has never invented anything. And hardly "pleasantly" eccentric. A five-year legal battle between this unusual ex-student and one of Philadelphia's premier educational institutions has gone largely unnoticed by the media and the public. Because no one gives a **** about a 50 year old loser. But it has been the subject of much attention in academia. Drexel says it dismissed Morein in 1995 because he failed, after eight years, to complete a thesis required for a doctorate in electrical and computer engineering. Not to mention the 12 years it took him to get thru high school! BWAAAAAAHAHAHAHAHAHAHAHAHA! Morein, 50, of Dresher, Pa., contends that he was dismissed only after his thesis adviser "appropriated" an innovative idea Morein had developed in a rarefied area of thought called "estimation theory" and arranged to have it patented. A contention rejected by three courts. From a 50 YEAR OLD that has done NOTHING PRODUCTIVE with his life. In February 2000, Philadelphia Common Pleas Court Judge Esther R. Sylvester ruled that Morein's adviser indeed had taken his idea. An idea that was worth nothing, because it didn't work. Just like Robert Morein, who has never worked a day in his life. Sylvester held that Morein had been unjustly dismissed and she ordered Drexel to reinstate him or refund his tuition. Funnily enough, Drexel AGREED to reinstate Morein, who rejected the offer because he knew he was and IS a failed loser. Spending daddy's money to cover up his lack of productivity. That brought roars of protest from the lions of academia. There is a long tradition in America of noninterference by the courts in academic decisions. Backed by every major university in Pennsylvania and organizations representing thousands of others around the country, Drexel appealed to the state Superior Court. The appellate court, by a 2-1 vote, reversed Sylvester in June 2001 and restored the status quo. Morein was, once again, out at Drexel. And the time-honored axiom that courts ought to keep their noses out of academic affairs was reasserted. The state Supreme Court declined to review the case and, in an ordinary litigation, that would have been the end of it. But Morein, in a quixotic gesture that goes steeply against the odds, has asked the highest court in the land to give him a hearing. Daddy throws more money down the crapper. His attorney, Faye Riva Cohen, said the Supreme Court appeal is important even if it fails because it raises the issue of whether a university has a right to lay claim to a student's ideas - or intellectual property - without compensation. "Any time you are in a Ph.D. program, you are a serf, you are a slave," said Cohen. Morein "is concerned not only for himself. He feels that what happened to him is pretty common." It's called HIGHER EDUCATION, honey. The students aren't in charge, the UNIVERSITY and PROFESSORS are. Drexel's attorney, Neil J. Hamburg, called Morein's appeal - and his claim that his idea was stolen - "preposterous." "I will eat my shoe if the Supreme Court hears this case," declared Hamburg. "We're not even going to file a response. He is a brilliant guy, but his intelligence should be used for the advancement of society rather than pursuing self-destructive litigation." No **** sherlock. The litigation began in 1997, when Morein sued Drexel claiming that a committee of professors had dumped him after he accused his faculty adviser, Paul Kalata, of appropriating his idea. His concept was considered to have potential value for businesses in minutely measuring the internal functions of machines, industrial processes and electronic systems. The field of "estimation theory" is one in which scientists attempt to calculate what they cannot plainly observe, such as the inside workings of a nuclear plant or a computer. My estimation theory? There is NO brain at work inside the head of Robert Morein, only sawdust. Prior to Morein's dismissal, Drexel looked into his complaint against Kalata and concluded that the associate professor had done nothing wrong. Kalata, through a university lawyer, declined to comment. At a nonjury trial before Sylvester in 1999, Morein testified that Kalata in 1990 had posed a technical problem for him to study for his thesis. It related to estimation theory. Kalata, who did not appear at the trial, said in a 1998 deposition that a Cherry Hill company for which he was a paid consultant, K-Tron International, had asked him to develop an alternate estimation method for it. The company manufactures bulk material feeders and conveyors used in industrial processes. Morein testified that, after much study, he experienced "a flash of inspiration" and came up with a novel mathematical concept to address the problem Kalata had presented. Without his knowledge, Morein said, Kalata shared the idea with K-Tron. K-Tron then applied for a patent, listing Kalata and Morein as co-inventors. Morein said he agreed "under duress" to the arrangement, but felt "locked into a highly disadvantageous situation." As a result, he testified, he became alienated from Kalata. As events unfolded, Kalata signed over his interest in the patent to K-Tron. The company never capitalized on the technology and eventually allowed the patent to lapse. No one made any money from it. Because it was bogus. Even Kalata was mortified that he was a victim of this SCAMSTER, Robert Morein. In 1991, Morein went to the head of Drexel's electrical engineering department, accused Kalata of appropriating his intellectual property, and asked for a new faculty adviser. The staff at Drexel laughed wildly at the ignorance of Robert Morein. He didn't get one. Instead, a committee of four professors, including Kalata, was formed to oversee Morein's thesis work. Four years later, the committee dismissed him, saying he had failed to complete his thesis. So Morein ****s up his first couple years, gets new faculty advisers (a TEAM), and then ****s up again! Brilliant! Morein claimed that the committee intentionally had undermined him. Morein makes LOTS of claims that are nonsense. One look thru the usenet proves it. Judge Sylvester agreed. In her ruling, Sylvester wrote: "It is this court's opinion that the defendants were motivated by bad faith and ill will." So much for political machine judges. The U.S. Supreme Court receives 7,000 appeals a year and agrees to hear only about 100 of them. Hamburg, Drexel's attorney, is betting the high court will reject Morein's appeal out of hand because its focal point - concerning a student's right to intellectual property - was not central to the litigation in the Pennsylvania courts. Morein said he understands it's a long shot, but he feels he must pursue it. Just like all the failed "causes" Morein pursues. Heck, he's been chasing another "Brian McCarty" for years and yet has ZERO impact on anything. Failure. Look it up in Websters. You'll see a picture of Robert Morein. The poster boy for SCAMMING LOSERS. "I had to seek closure," he said. Without a doctorate, he said, he has been unable to pursue a career he had hoped would lead him into research on artificial intelligence. Who better to tell us about "artificial intelligence". BWAAAAAAAAAHAHAHAHAHAHAHAHAHAHA! As it is, Morein lives at home with his father and makes a modest income from stock investments. He has written a film script that he is trying to make into a movie. And in the basement of his father's home he is working on an invention, an industrial pump so powerful it could cut steel with a bulletlike stream of water. FAILED STUDENT FAILED MOVIE MAKER FAILED SCREENWRITER FAILED INVESTOR FAILED DRIVER FAILED SON FAILED PARENTS FAILED INVENTOR FAILED PLAINTIFF FAILED HOMOSEXUAL FAILED HUMAN FAILED FAILED But none of it is what he had imagined for himself. "I don't really have a replacement career," Morein said. "It's a very gnawing thing." |
#11
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Loudspeaker timing
"Arny Krueger" wrote in message ... "Bob Morein" wrote in message ws.com \ This would be a forged post from Brian McCartey. Yes, it would be forged. And you have my rare compliment on a good exposition. |
#12
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Loudspeaker timing
"Lionel" wrote in message ... Bob Morein wrote: "Lionel" wrote in message ... Brian l. McCarty wrote: On 29/9/03 14:27, in article , "Sam" wrote: Many loudspeakers incorporate some type of time alighnment scheme in their design such as a sloping baffle. Is this truly necessary? Nope. For the theory to be accurate, you'd have to sit in one very precisely measure location, and never move your head even a millimeter. It makes good marketing copy, however. Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. I think you have the answer. Time alignment has long been repudiated as speaker designer snake oil. Sir, I just want to say that you are a *jerk*. ;-) Lionel It's a rare opportunity to address Brian personally. I second Lionel's opinion. You are a *jerk*. I know it's really mesquin and vain but sometime vengeance is as good as a fresh beer. ;-) You know it, bud! |
#13
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Loudspeaker timing
"Bob Morein" wrote in message
"Arny Krueger" wrote in message ... "Bob Morein" wrote in message ws.com \ This would be a forged post from Brian McCartey. Yes, it would be forged. And you have my rare compliment on a good exposition. I would recommend that as many people as possible complain to Brian's ISP by forwarding the forged post, including a copy of the headers, . This is not a futile action if enough people get on board. If anybody needs help obtaining the headers, here's they a Headers for Brian McCartey's forged post: X-Abuse-Report: Message-ID: om Path: news5.aus1.giganews.com!firehose2!nntp4!intern1.nn tp.aus1.giganews.com!borde r1.nntp.aus1.giganews.com!nntp.giganews.com!in.100 proofnews.com!in.100proofn ews.com!snoopy.risq.qc.ca!chi1.webusenet.com!news. webusenet.com!newsfeed-eas t.nntpserver.com!nntpserver.com!news.sonicnews.com !not-for-mail Date: Mon, 29 Sep 2003 10:22:00 GMT Lines: 254 User-Agent: Microsoft-Entourage/10.1.1.2418 Subject: Loudspeaker timing From: Bob Morein Newsgroups: rec.audio.opinion References: Mime-version: 1.0 Organization: Comcast Pennsylvania Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Xref: intern1.nntp.aus1.giganews.com rec.audio.opinion:683216 |
#14
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Loudspeaker timing
On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty"
wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. |
#15
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Loudspeaker timing
"dave weil" wrote in message
news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. Lovely. Weil re-writes the laws of physics to read that the speed of sound is significantly and perceptibly dependent on frequency. Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! LOL! |
#16
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Loudspeaker timing
On Mon, 29 Sep 2003 09:59:59 -0400, "Arny Krueger"
wrote: "dave weil" wrote in message news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. Lovely. Weil re-writes the laws of physics to read that the speed of sound is significantly and perceptibly dependent on frequency. Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! LOL! Obviously, *you* haven't been paying attention in church. |
#17
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Loudspeaker timing
"dave weil" wrote in message news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. I don't believe that the speed of sound is frequency dependent. If it was, an octave would only be in tune at a specific distance, which we know is not the case. Norm Strong |
#18
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Loudspeaker timing
On Mon, 29 Sep 2003 09:59:59 -0400, "Arny Krueger"
wrote: Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! I know I'm going to regret asking this, but why exactly do you think dave would fake a review of Greg's speakers? LOL! Lies Oh Lies. -- td |
#19
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Loudspeaker timing
"dave weil" wrote in message news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. He probably has. He plays or played multiple musical instruments. Although he is currently insane, he may have been fairly normal earlier in life. |
#20
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Loudspeaker timing
"dave weil" wrote in message news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. You may be confused by the fact that reverberation is frequency dependent. However, the speed of propagation of sound is not: http://www.physics.utoronto.ca/~marj...ics/LinPP.html |
#21
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Arny Krueger wrote:
"dave weil" wrote in message news On Mon, 29 Sep 2003 07:07:02 GMT, "Brian l. McCarty" wrote: Can people actually perceive the difference in speed between high frequencies and low frequencies? Nope. Obviously Brian has never attended a live music event in a large hall. Lovely. Weil re-writes the laws of physics to read that the speed of sound is significantly and perceptibly dependent on frequency. Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! LOL! I'm laughing too, at your supposed religious beliefs! |
#22
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"Bob Morein" wrote in message ws.com... On 29/9/03 23:59, in article , "Arny Krueger" wrote: Lovely. Weil re-writes the laws of physics to read that the speed of sound is significantly and perceptibly dependent on frequency. Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! You'd be surprised how much "accepted" physics is just plain wrong. Especially when it comes to audio. Yet another forgery! X-Abuse-Report: Message-ID: om Path: news5.aus1.giganews.com!firehose2!nntp4!intern1.nn tp.aus1.giganews.com!borde r1.nntp.aus1.giganews.com!nntp.giganews.com!cyclon e-sf.pbi.net!216.218.192.2 42!news.he.net!newsfeed1.easynews.com!easynews.com !easynews!newsfeed-east.nn tpserver.com!nntpserver.com!news.sonicnews.com!not-for-mail Date: Mon, 29 Sep 2003 17:32:43 GMT Lines: 13 User-Agent: Microsoft-Entourage/10.1.1.2418 Subject: Loudspeaker timing From: Bob Morein Newsgroups: rec.audio.opinion References: om Mime-version: 1.0 Organization: Comcast Pennsylvania Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Xref: intern1.nntp.aus1.giganews.com rec.audio.opinion:683319 |
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"Arny Krueger" wrote in message ... "Bob Morein" wrote in message ws.com... On 29/9/03 23:59, in article , "Arny Krueger" wrote: Lovely. Weil re-writes the laws of physics to read that the speed of sound is significantly and perceptibly dependent on frequency. Singh lets Weil pretend to review one of his POS speakers, and now Weil is rewriting physics books! You'd be surprised how much "accepted" physics is just plain wrong. Especially when it comes to audio. Yet another forgery! I can tell without even looking at the headers . |
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#25
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Loudspeaker timing
So you are saying that loudspeaker timing has to do with the audio
signal going to the loudspeakers and not the actual speed of the sounds coming from the drivers. I made the false assumption that different frequencies of sound traveled at different speeds. Why are the signals going to the woofer and tweeter not aligned with one another? Does the crossover network cause a phase shift in the signals that pass through them? Speakers and their design really fascinate me but there is much I need to learn. Do you know of a good website that explains the whole timing issue? Sam |
#26
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"Sam" wrote in message om... So you are saying that loudspeaker timing has to do with the audio signal going to the loudspeakers and not the actual speed of the sounds coming from the drivers. I made the false assumption that different frequencies of sound traveled at different speeds. Why are the signals going to the woofer and tweeter not aligned with one another? Does the crossover network cause a phase shift in the signals that pass through them? Speakers and their design really fascinate me but there is much I need to learn. Do you know of a good website that explains the whole timing issue? Sam I don't know of a website, but here's a brief rundown: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. The part of the problem caused by driver delay can be corrected by sloping the baffle, so as to place the tweeter further away from the listener than the woofer. 2. A typical crossover makes time alignment impossible. At best, a phase alignment at the crossover point can be accomplished. Time alignment is possible only with a "first order crossover", which allows considerable leakage of low frequency input to the tweeter. This stresses the tweeter, with a tendency to promote thermal burnout. Tweeters put into systems with first order crossovers must be specially constructed or used lightly. 3. You may hear the terms "phase alignment" and "time alignment". These are two different criteria. In principle, time alignment is a tighter, more difficult design criteria. For continuous wave signals, the result is the same. For signals which contain non continuous wave components, ie., music, they are different. Auditory research suggests that complex noises are not localized by time delay. However, the ear can distinguish intra-aural time delays as small as 6 microseconds. This suggests that while a time aligned speaker may not help one better distinguish the position of a violinist, it may help the listener distinguish the positions of percussive noises or other transients. |
#27
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On Mon, 29 Sep 2003 06:45:56 -0400, "Arny Krueger"
wrote: I often engage in adolescentilism. That's very honest of you. -- td |
#28
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"The Devil" wrote in message news:ledhnv4unltuletcnna9t19jmtcd8qhndv@rdmzrnewst xt.nz... On Mon, 29 Sep 2003 06:45:56 -0400, "Arny Krueger" never wrote: I often engage in adolescentilism. I lie and drink a lot because reality is way to bitter for me. Thanks for sharing, Graham. |
#29
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"Sam" wrote in message om... So you are saying that loudspeaker timing has to do with the audio signal going to the loudspeakers No, it has to do with the sound coming out of the speakers. The timing of the sound coming out of a speakers is partially determined by the signal going into the speakers. and not the actual speed of the sounds coming from the drivers. The speed of sound is essentially the same from all of the speakers in the system. I made the false assumption that different frequencies of sound traveled at different speeds. Yes, you did, and thank you for seeing your error. Why are the signals going to the woofer and tweeter not aligned with one another? They may or may not be aligned with each other, depending on the crossover system design. One effect you haven't mentioned is the fact that the time delay between the electrical signal going into the speaker, and the acoustic signal (sound) coming out of the speaker also varies with the speaker type and frequency. Does the crossover network cause a phase shift in the signals that pass through them? Yes. Speakers and their design really fascinate me but there is much I need to learn. Do you know of a good website that explains the whole timing issue? Introduction: http://www.libinst.com/tpfd.htm Very theoretical: http://www.whise.com.au/time_delay.htm More practical: http://www.mlssa.com/mlssa/BROCHUREp2.htm A book on the topic and others: http://www.trueaudio.com/ild_rev1.htm |
#30
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On Mon, 29 Sep 2003 21:51:34 -0400, "Arny Krueger"
wrote: I often engage in adolescentilism. Tha t doesn't surprise me at all. I forgot to mention that I'm a repulsive pervert who should be strung up by his balls. I totally agree. -- td |
#31
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Loudspeaker timing
On Mon, 29 Sep 2003 16:23:45 -0400, "Bob Morein"
wrote: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. One might take some notice if one wanted to throw them. This must be one of the worst cases of a feral physicist technobabble. You are loosing(tm) it Bob, IMO. Ask Dick to clean your clock. This group is in danger of going to the dogs. . . |
#32
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Loudspeaker timing
"Goofball_star_dot_etal" wrote in message ... On Mon, 29 Sep 2003 16:23:45 -0400, "Bob Morein" wrote: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. One might take some notice if one wanted to throw them. This must be one of the worst cases of a feral physicist technobabble. You are loosing(tm) it Bob, IMO. The wording is an attempt to avoid confusing the reader with moving mass, resonant frequency, and Q. Why don't you give it a shot? It could be better. |
#33
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Goofball_star_dot_etal wrote:
On Mon, 29 Sep 2003 16:23:45 -0400, "Bob Morein" wrote: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. One might take some notice if one wanted to throw them. This must be one of the worst cases of a feral physicist technobabble. You are loosing(tm) it Bob, IMO. Ask Dick to clean your clock. This group is in danger of going to the dogs. . . Only "in danger" ? |
#34
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My loudspeaker had great timing. It showed up on the market exactly
when I needed a new speaker. Norm Strong |
#35
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On 01 Oct 2003 18:16:29 GMT, (Nousaine) wrote:
"normanstrong" wrote: My loudspeaker had great timing. It showed up on the market exactly when I needed a new speaker. Norm Strong My experience is that speakers may often have unfortunate or really bad timing. For example I have a woofer that arrived last week but my deadline isn't for another month. OTOH I often receive speakers today for a deadline of yesterday. The trucks don't have the right weight. |
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#37
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Loudspeaker timing
Goofy said: The trucks don't have the right weight. That's what you get for hauling too many willies. |
#38
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On Tue, 30 Sep 2003 18:47:46 -0400, "Bob Morein"
wrote: "Goofball_star_dot_etal" wrote in message ... On Mon, 29 Sep 2003 16:23:45 -0400, "Bob Morein" wrote: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. One might take some notice if one wanted to throw them. This must be one of the worst cases of a feral physicist technobabble. You are loosing(tm) it Bob, IMO. The wording is an attempt to avoid confusing the reader with moving mass, resonant frequency, and Q. Why don't you give it a shot? It could be better. It is not just a case of dumbing down the wording for the confused reader. I fail to see a simple relationship between mass and time delay. If you were to increase just the mass of the moving parts of an ideal driver, for a frequency well above resonance, the amplitude of acceleration, velocity and displacement would all be reduced in proportion to mass but the phase/time relationship between air pressure and applied voltage would be the same. If you scale down a driver in proportion to wavelength, a lot more than just the mass is changed including the applied force, but again, well above resonance, the applied force and therefore acceleration, is proportional to the applied current ( or voltage for constant impedance) and the velocity and displacement just follow along in proportion, ninety degrees apart. (assuming a ideal rigid structure). I can see no increased delay due to increased moving mass of drivers. Scaling can be a tricky thing, you will note but the motion of "ideal" drivers is not. Maybe you are thinking of something tricky but it came out dumb - "heavy equals slow/late" There is also something dumb here too, we noted. . . "Auditory research suggests that complex noises are not localized by time delay. However, the ear can distinguish intra-aural time delays as small as 6 microseconds. This suggests that while a time aligned speaker may not help one better distinguish the position of a violinist, it may help the listener distinguish the positions of percussive noises or other transients." How can you change "intra-aural time delays" by any identical change to two identical speakers? |
#39
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On Wed, 01 Oct 2003 14:47:20 -0400, George M. Middius
wrote: Goofy said: The trucks don't have the right weight. That's what you get for hauling too many willies. Just say NO to goofy audio. |
#40
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Loudspeaker timing
"Goofball_star_dot_etal" wrote in message ... On Tue, 30 Sep 2003 18:47:46 -0400, "Bob Morein" wrote: "Goofball_star_dot_etal" wrote in message ... On Mon, 29 Sep 2003 16:23:45 -0400, "Bob Morein" wrote: 1. The woofer weighs more than the tweeter. Hence it responds slower to the driving electrical signal. One might take some notice if one wanted to throw them. This must be one of the worst cases of a feral physicist technobabble. You are loosing(tm) it Bob, IMO. The wording is an attempt to avoid confusing the reader with moving mass, resonant frequency, and Q. Why don't you give it a shot? It could be better. It is not just a case of dumbing down the wording for the confused reader. I fail to see a simple relationship between mass and time delay. If you were to increase just the mass of the moving parts of an ideal driver, for a frequency well above resonance, the amplitude of acceleration, velocity and displacement would all be reduced in proportion to mass but the phase/time relationship between air pressure and applied voltage would be the same. If you scale down a driver in proportion to wavelength, a lot more than just the mass is changed including the applied force, but again, well above resonance, the applied force and therefore acceleration, is proportional to the applied current ( or voltage for constant impedance) and the velocity and displacement just follow along in proportion, ninety degrees apart. (assuming a ideal rigid structure). I can see no increased delay due to increased moving mass of drivers. Scaling can be a tricky thing, you will note but the motion of "ideal" drivers is not. Maybe you are thinking of something tricky but it came out dumb - "heavy equals slow/late" All correct, above. I was trying to give Sam, who was not aware that the speed of sound in free space is independent of frequency, something to grab on to. Doing that, while exhibiting the level of erudition we expect, is for me an unsolved problem. So I decided to focus on the relationship between resonant frequency and group delay, and resonant frequency, I decided, was best represented by one constant in the equation, mass. If you can think of a way to present more information to Sam, who has just learned that c is a constant, it would be useful to all of us. Give it another shot. I'd certainly add it to my repertoire of answers, as the question will inevitably occur again. There is also something dumb here too, we noted. . . "Auditory research suggests that complex noises are not localized by time delay. However, the ear can distinguish intra-aural time delays as small as 6 microseconds. This suggests that while a time aligned speaker may not help one better distinguish the position of a violinist, it may help the listener distinguish the positions of percussive noises or other transients." How can you change "intra-aural time delays" by any identical change to two identical speakers? That's a good question. It's intuitively appealing to me that the ear would better be able to localize an impulse if it actually looks like an impulse, as opposed to what you and I both know comes out of a non time-aligned system. And that's all there is. I have no testing, blind or otherwise, to back it up. I do know I enjoy the hell out of a set of Spicas when they're set up right. |
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