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#121
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Measuring audio bandwidth
Nousaine wrote:
So what have YOU published? Ever wonder why people accuse you of being an arrogant ****? This kind of logical fallacy is meaningless: just because your name appears in a rag with nickel and dime circulation doesn't mean you're right, or that you know more than anyone else (except perhaps your editors). How do YOU explain how turning an omnidirectional speaker in one direction or another manages to make it generate MORE displacement/SPL with a given drive level? I don't explain it, and I don't because I don't believe in omnidirectional speakers. There's no such thing. The lack of directionality in drivers producing bass is a function of how human ears determine localization. Furthermore - and I have pointed this out - bass is not isotropic, nor is it invariant. Maybe you're unfamiliar with this concept, but sound travels. How do YOU get around the fact that there was no modal action in his measurements (which he based his argument upon), no SPL distribution changes and yet his mearements showed a general equal level shift over the entire range? Im wondering why it is you expect there to be anything other than a "general equal level shift". You act as if a small gain in SPL should result in massive chaotic changes in the response curves. Algebra 101, Tommy boy...the result of any function and a constant real number + n yields nothing more than a vertical shift of the graph of a function by +n. Eddie didn't change the box, he didn't change the car, and he didn't change the music. Eddie just pointed the woofer another direction, got a little gain, and that's why overall the graphs are the same. However, you noted the minute deviations, and that should be enough to satisfy your curiousity about 'modal actions', considering the loose tolerances being dealt with in this experiment. Exactly how does a woofer system with a given displacement capability "know" how be louder depending on which direction its facing? Please; we want to know. It doesn't have to. You're really bearing out your ignorance here. This is a really simple concept. It's understood by every installer and every kid who has ever tossed a box in a car. On the other end, it's easily explained by anyone with a fundamental understanding of physics. Somewhere in between is you, arguing that it doesn't actually happen. -- Lizard |
#122
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Standing wave definition explained
Eddie Runner wrote:
I make a mistake in spelling and Tom wont let it pass! Come on Tom lets talk TECH not SPELLING! (is that all ya got?) Tom is apparently hook't on fonicks. See below: Nousaine wrote: Great; read some of them when you get a chance. Start with Baranek. Not banacek, or something similar as you once tried to posture. pos·ture ( P ) Pronunciation Key (pschr) n. 1. 1. A position of the body or of body parts: a sitting posture. 2. An attitude; a pose: assumed a posture of angry defiance. 2. A characteristic way of bearing one's body; carriage: stood with good posture. 3. Relative placement or arrangement: the posture of the buildings on the land. 4. A stance or disposition with regard to something: “Those bases are essential to our military posture in the Middle East” (Gerard Smith). 5. A frame of mind affecting one's thoughts or behavior; an overall attitude. I think Tommy-boy means "posit". pos·it ( P ) Pronunciation Key (pzt) tr.v. pos·it·ed, pos·it·ing, pos·its 1. To assume the existence of; postulate. See Synonyms at presume. 2. To put forward, as for consideration or study; suggest: “If a book is hard going, it ought to be good. If it posits a complex moral situation, it ought to be even better” (Anthony Burgess). 3. To place firmly in position. I think it's safe to say Tommy has no business telling Eddie about spelling...or vocabulary...he can't even get simple physics right. -- Lizard |
#123
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Standing wave definition explained
Tom must be out of options to be picking on spelling
and calling folks names.... This arguement started quite a while ago, maybe years ago when Tom first attacked my web article.. I traded a few emails with him and he would not even listen to reason so I have been mostly quiet about this subject for a long long time, knowing I would someday get time to post some tests..... Now I finally got some free time in the shop and got all the test gear together and did some measurements and some graphs I could post to show Tom that moving the woofer box around in the car DOES make a difference..... Now he seems to be going off on ever tangent imagineable. (I guess he doesnt want to admit he was wrong) I would like it if we just stuck to basics... Can moving the woofer box around in a car change the bass? I say YES My graphs http://www.installer.com/tech/aiming2.html seem to say YES... The way I understand it Tom has always said NO.... To me that was the issue, not calling names, not who has been published more, not who can **** the fiurthest... My test results are published, if Tom doesnt like it he is welcome to publish his own findings... Eddie Runner |
#124
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One question for Tom.
"Eddie Runner" wrote in message ... Im not trying to LOOSE you im just trying to make the subject match the actual meat in the message,.. if you sort by thread with your newsreader the messages will still be apart of the old thread even if the title changes. in outlook it is in view current view group messages by conversation if you have a different newsreader, let us know and we'll help ya set it up so you can follow a thread... how long you been at this? -- sancho |
#125
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Standing wave definition explained
My test results are published, if Tom doesnt like it he is welcome to publish his own findings... i get the distinct feeling that 'tom' has either not bothered to look at your page or has not really looked at the graphs... -- sancho i could be wrong |
#126
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Actual tests - aiming woofer boxes
Tom,
Easy question with an easy answer. Yes or No please. Did turning the sub box around make a noticeable increase in dBSPL at the listening position??? Yes or No, simple question. Les |
#127
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Measuring audio bandwidth
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#128
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Measuring audio bandwidth
I had already done this kinda sweep many times in the past but I
didnt have any of the old graphs archived where I could get to them.... So eventually I upgraded my shop computer and found a little time to prove it to you... Oh really; you'd done this before but had never archived it? And never validated your cartoons with data? As I have. Why would he need to archive it? I do sweeps and graphs of rooms using Smaart all the time but I dont archive them. But why do you continually avoid the basic questions. Exactly HOW does a woofer/amp system generate MORE sound pressure when faced in a given directionn when there's NO sound pressure variation relative to the space it's in? No boundary interaction? How? Please!!! How can it NOT???? It did. Look at the graphs. How at this point is irrelevent, but the fact that you cannot even admit that it does with the evidence looking right at you is pathetic. What "lies" have you found? Please be explicit. Use google. Its there. I have read it. Dont forget TOM, you attacked the credibility of my CARTOONS about this phenomenon way before I ever called you on the ****ty article you wrote claiming moving a subwoofer around in a car makes NO DIFFERENCE..... Bull****. I just mentioned that the effects you were claiming didn't fit with the current las of physics the rest of us live with on a day-to-day basis. Tom, Come on now. Did the damn sound get louder at listening position or not? EXACTLY how does a woofer systen KNOW it's supposed to generate MORE SPL in a given space depending on whichj direction it's facing? The woofer system doesnt know. The interactions are what makes it happen. It obviously got louder, why dont you explain how? You asked for it.... You're right and I'm dishing it out too. Why can't you answer basic physics questions? How does your cartoon explain "standing wave" effects when the sound "waves" are traveling in the SAME direction? Help me he does not the wave pattern you show depend on the reflection coming "back" to the direct sound and traveling in the same direction as the original sound beyond the point of incidence? No???? Help us here. Meaningless drivel by Tom still skirting the issue. Did it get louder?????????? What say you? Now I know exactly the acoustics hee; but you apparently do NOT. So why not step into some more bull****. It seems you like that environment. All this is too bad. In many of your "proclimations" I fully agree. Wires IS wires. But when seemingly rational people spout bull**** it downsizes all of us. Tom, if anyone in the "business" is downsizing all of us it is you. A poser. The problem lay with your bull**** arguments where you are clearly wrong and can't answer simple questions such as; how does a woofer system with a given amplifier KNOW that it's supposed to play louder when its owner turns it around? r. So exactly WHERE is that mysterious improvement we get with woofer turning? Help me here, please. Your the acoustics "expert" so you tell us?? IT OBVIOUSLY HAPPENS. Eddie has taken all of your ways around actually answering the questions and eliminated them, You have none of your own strawman arguments left. Regardless of whether you agree with his explanation of it the FACT is still there, There was a noticeable difference in several vehicles in dBSPL in bass frequencies. So explain how that happened?? Les |
#129
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Measuring audio bandwidth
On Fri, 05 Dec 2003 22:24:13 GMT, Eddie Runner
wrote: Tom, I dont know why you are acting like I am new to this..?? I have been taking measurements like this from cars for over 20 years, (and the RF spectrum for 30 years) in the early days audio with a meter and plotting a limited number of points into a computer by hand so the computer could draw the graph for storage. Not long after with RTAs and eventually with the LMS system originally with thier DOS program but upgraded to the new windows version just the other day... Eddie Runner http://www.installer.com/tech/aiming2.html Eddie, I just got done looking at you page of measurements. Pretty impressive, but just from an engineer's perspective, don't those changes in frequency response look a little too radical to you? I wouldn't be surprised to see a few dB difference depending on which way the sub was facing, but those 100 Hz numbers would have me concered about the validity of either the test or the equipment. After all, the front-facing sub was 23 dB down in the Neon, and almost 28 dB down in the Jetta. That means that the energy at the microphone was reduced by more than a factor of 128 in the Neon, and by more than a factor of 500 in the Jetta. Either the microphone location happened to be an almost perfect node for the forward-firing sub, and an almost perfect anti-node for the rear-firing, or something's amiss. Don't get me wrong, I don't suspect you of any shenanigans at all, but when a graph tells me that flipping the sub around caused the energy level at the microphone to increase **500 times**, I suspect the equipment or the software. Scott Gardner |
#132
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Toms ****ed now!
That's true; figures don't lie ...but some times liars figure...
Tom I think alot of your tests are lies. I think you doctor the data to give results you want. Thats a pretty assholish thing to say isnt it? BUT that is EXACTLY what your saying. You bitch and moan about strawman arguments and yet you are the KING of the strawmen. You cannot answer the question. DID IT GET LOUDER??????? Its simple. But since it doesnt fit with what you say it is obviously a lie. Come on, enough with the BULL**** and answer that ONE question. Ignore everything else I might write but answer just that one. Les |
#133
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Tom is Unclear
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#134
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TOM says Eddie is an AMATEUR (he must be deperate)
Eddie Runner wrote:
Nousaine wrote: Im no amateur Tom... I been in audio professionally for almost 30 years! So? So has Amar Bose. Although I've not listened to any of your 'systems' that I'm aware of, my guess is that any if your systems will cost 4X more and sound half as good as the Bose Premuim upgrade in that vehicle., you'd be really lucky. Only based on my experience with 200 hundred after-market systems (IASCA judge) and perhaps 400 OEM systems between 'prototype' and ":sold directly to the public." Sure. But you are an amateur with regard to acoustics and room acoustics. Your insults are pretty meaningless... I have probably spent more time in ROOMS and especially CARS with RTAS and test equipment than you have.... Reguardless to that fact which may or may not be true... I have obviously spent ENOUGH time to not be called an amateur... So prove it; tell us something that is based on fact and not your biased opinion. Plus, the defintion of an Amateur would certainly be if I got PAID! And trust me I have been doing this kind of work professionally for nearly 30 years... Before that my love of audio was certainly of an amateur nature, but still probably more advanced than the average amateur.... I'd agree that the qualifier `"paid" isn't interesting. Your statements about ME being an AMATEUR are obviously manfested by you because of some inadequacy you might have or some jealousy or .... Heck I dont know why you are making up these insults... Everyone here knows me, some of them say I have been doing this sort of work longer than dirt has existed.... Actually it seems like you are probably accomplished in installation but acoustically you are not in the ballpark. You seem to unaware of the acoustc benefits of the car cabin (assigning those benefits to customers as directional effects) transfer function. Your insults are only affecting your own credibility in this issue Insults? That's your BAG Eddie. You just will not discuss acoustics. I'm guessing that's because you aren't conversent in them. But, I'll talk/chat to anyone who is inerested. Along with your inability to produce any evedence Oh, and your statements about turning a woofer box backward in a car wont make any difference to the woofer sound in the car... Eddie Runner http://www.installer.com/tech/ So Eddie; tell me again exactly how any given woofer with a known displacement in a given enclosure in a known space with a given amplifier can "decide" to make more SPL" when faced in one direction or another. PLEASE Double PLEASE. I 'know' I'm stupid; but please tell me and everyone else how we're wrong. |
#135
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TOM says Eddie is an AMATEUR (he must be deperate)
You just will not discuss acoustics. I'm
guessing that's because you aren't conversent in them. But, I'll talk/chat to anyone who is inerested. Bull****. I have asked a simple acoustics related question several times and you have yet to reply. The graphs show its louder Tom. HOW did that happen. We know the woofer doesnt "know" to play louder and doesnt so there must be some acoustical property at work. Explain it. |
#136
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Measuring audio bandwidth
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#137
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Measuring audio bandwidth
thelizman thelizman1221.yahoo@com wrote:
Nousaine wrote: So what have YOU published? Ever wonder why people accuse you of being an arrogant ****? This kind of logical fallacy is meaningless: just because your name appears in a rag with nickel and dime circulation doesn't mean you're right, or that you know more than anyone else (except perhaps your editors). I'd agree with that. So exactly where can we find you "arrogant ****" analysis of the data and your "arrogant ****" description of your contrary results? Please. I'd be happy to know how much you really know. How do YOU explain how turning an omnidirectional speaker in one direction or another manages to make it generate MORE displacement/SPL with a given drive level? I don't explain it, and I don't because I don't believe in omnidirectional speakers. There's no such thing. Sure fully omni-speakers don't exist at high frequencies. But, tell me exactly 'why' Eddie's pix show truly omni results below 100 hZ? If the speakers were'nt omni then why weren't there frequency dependent effects? The lack of directionality in drivers producing bass is a function of how human ears determine localization. Furthermore - and I have pointed this out - bass is not isotropic, nor is it invariant. Maybe you're unfamiliar with this concept, but sound travels. And so what? If a human can't hear or percieve it, who cares? So tell us how do your isotropic and non-invariant qualities affect human perception of low frequencies? How do YOU get around the fact that there was no modal action in his measurements (which he based his argument upon), no SPL distribution changes and yet his mearements showed a general equal level shift over the entire range? Im wondering why it is you expect there to be anything other than a "general equal level shift". You act as if a small gain in SPL should result in massive chaotic changes in the response curves. Algebra 101, Tommy boy...the result of any function and a constant real number + n yields nothing more than a vertical shift of the graph of a function by +n. Total bull****. Where is there any "gain": going on? How does a fixed system (speaker/power/interior acoustics) have any acoustic 'gain' by shifting the direction of the acoustic radiating face? You want to give me a physics 101 answer? Eddie didn't change the box, he didn't change the car, and he didn't change the music. Eddie just pointed the woofer another direction, got a little gain, and that's why overall the graphs are the same. So exactly how did he get any acoustic 'gain' ? You're telling me that turning a given subwoofer speaker system one way or another changes the Vd or the amplifier input or the enclosure size? Exactly how does it DO that? How does it "know" that it's supposed to do that depending on direction? Help us out here. However, you noted the minute deviations, and that should be enough to satisfy your curiousity about 'modal actions', considering the loose tolerances being dealt with in this experiment. Loose tolerances? I'm guessing that you must know Eddie then. Exactly how does a woofer system with a given displacement capability "know" how be louder depending on which direction its facing? Please; we want to know. It doesn't have to. You're really bearing out your ignorance here. This is a really simple concept. It's understood by every installer and every kid who has ever tossed a box in a car. Really? So help me out. Exactly How does a woofer system "know" that it's supposed to increase the ampliifer power delivered or increase its known excursion limits or expand its cone area depending on which way its facing? If this is so "easy" then you or Eddie should be able to explain it post haste. I'm wondering why you (or he) hasn't already done this. On the other end, it's easily explained by anyone with a fundamental understanding of physics. Somewhere in between is you, arguing that it doesn't actually happen. -- Lizard OK help me out with that fundamental undertanding of physics. Exactly how does a woofer system "know" that it's suppoded to deliver MORE output when its facing in this direction? How about North? Or was that South? Does the SPL then vary with vehicle direction? Do I get MORE bass traveling east or west? Please help me because I'm obviously hopelessly clueless. Thanks in advance. |
#138
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Actual tests - aiming woofer boxes
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#139
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Standing wave definition explained
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#141
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Very desperate now
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#142
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Standing wave definition explained
Eddie Runner wrote:
Tom must be out of options to be picking on spelling and calling folks names.... I've never name-called Eddie. Nor have I misreprented your position, as you have consistently done to me. This arguement started quite a while ago, maybe years ago when Tom first attacked my web article.. I've never 'attacked' anything. I merely pointed out, quite politely, that your explanation about low frequency effects in cars was wrong. I traded a few emails with him and he would not even listen to reason so I have been mostly quiet about this subject for a long long time, knowing I would someday get time to post some tests..... Now I finally got some free time in the shop and got all the test gear together and did some measurements and some graphs I could post to show Tom that moving the woofer box around in the car DOES make a difference..... I've never said that it doesn't. It just doesn't happen the way that you said it does. And your data, take it straight as it is, doesn't support your 'standing-wave cancellation' theory. Now he seems to be going off on ever tangent imagineable. (I guess he doesnt want to admit he was wrong) I would like it if we just stuck to basics... Can moving the woofer box around in a car change the bass? I say YES My graphs http://www.installer.com/tech/aiming2.html seem to say YES... The way I understand it Tom has always said NO.... No, only in the way you intentionally mis-represent it. I've never said that changing woofer orientation has "no" effect. It just doesn't change anything below the lowest modal frequency in any given space. And even your data shows that there's no standing wave effects going on below 60 Hz. To me that was the issue, not calling names, not who has been published more, not who can **** the fiurthest... My test results are published, if Tom doesnt like it he is welcome to publish his own findings... Eddie Runner Which I have dating back to nearly a decade. And which I continously publish 6-10 times a year. But, unlike you I can explain the car cabin transfer function. I can explain why standing wave effects don't occur below some reasonably low frequency in a given auto-platform size. In the meantime Eddie can only conduct experiments that have results he can't explain and don't show the effects he has claimed on his web-site and call me names. |
#143
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One question for Tom.
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#144
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Actual tests - aiming woofer boxes
keep after him with that question, I dont think Tom
wants to answer it now that I have published the sweeps. Before I published the sweeps he often said Nousaine wrote: Because acoustic sounds at subwoofer frequencies (approximately 100 Hz) are omnidirectional the SPL/Frequency response will be uneffected either way. Now he wont answer that question directly... Eddie Soundfreak03 wrote: Tom, Easy question with an easy answer. Yes or No please. Did turning the sub box around make a noticeable increase in dBSPL at the listening position??? Yes or No, simple question. Les |
#145
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Measuring audio bandwidth
Scott Gardner wrote:
http://www.installer.com/tech/aiming2.html Eddie, I just got done looking at you page of measurements. Pretty impressive, but just from an engineer's perspective, don't those changes in frequency response look a little too radical to you? I cant help how they look, I didnt make the sweeps the way I wanted them to look, I am just the messenger showing you how they DO LOOK! I did several measurements on 4 different cars so that folks could see and get thier own ideas about how important woofer positioning is. If the SPL goes up or down at any given frequency by moving the box, THE ONLY explanation can be reinforcment or cancellation because reflections that are in phase or out of phase. I say again its THE ONLY explanation! I wouldn't be surprised to see a few dB difference depending on which way the sub was facing, but those 100 Hz numbers would have me concered about the validity of either the test or the equipment. After all, the front-facing sub was 23 dB down in the Neon, and almost 28 dB down in the Jetta. Well alot of kids and installers know that turning the woofer box around can sometimes make DRASTIC differences!! The few DB in alot of the sweeps (IMO) would not be very drastic for most folks if they were not specificly listeing for it, so the 20+db must be the BIG difference we hear in alot of cars... It definatly IS a BIG difference ... That means that the energy at the microphone was reduced by more than a factor of 128 in the Neon, and by more than a factor of 500 in the Jetta. Either the microphone location happened to be an almost perfect node for the forward-firing sub, and an almost perfect anti-node for the rear-firing, or something's amiss. Well since the BIG DIFFERENCE is often heard in some cars I would just guess this anomaly IS that big difference... Folks have known of the phenomenon for quite some time. Here on RAC there were big threads about BASS TRAP about 7 or 8 years ago with the big dogs from JL audio and other audio companies basicly guessing about what happens... The old explanations were it takes time for the SPL to develop. Long waves need longer spaces so aim the box to the rear. Opening the trunk is like porting the car. and so on... I learned along time ago that not only turning the box around sometimes gives HUGE improvements, but also opening a trunk with a box init will sometimes greatly increase bass....!! (or a car door). How can it be if you open a trunk and LET SOUND OUT can the SPL get better in the listening area... That was easy, the sound you let out is out of phase with other sounds when they combine in the listening area... There cannot be any other explanation (except Toms explanation that it does not happen at all)..... This, whether Tom likes it or not is a standing wave, or a NODE of a standing wave... Don't get me wrong, I don't suspect you of any shenanigans at all, but when a graph tells me that flipping the sub around caused the energy level at the microphone to increase **500 times**, I suspect the equipment or the software. Sorry, but its all I have to offer at this time.... I may post more graphs as I do more testing.. I have made an open invitation to anyone in the Houston area to drop by and I will sweep thier car for them.... Hopefully with enough cars we can understand all this better... Thanks Scott for questioning my results in a nice way. UNLIKE TOM is doing. Eddie Runner http://www.installer.com/tech/ |
#146
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TOM says Eddie is an AMATEUR (he must be deperate)
"Nousaine" wrote in message ... Eddie Runner wrote: Nousaine wrote: Im no amateur Tom... I been in audio professionally for almost 30 years! So? So has Amar Bose. Although I've not listened to any of your 'systems' that I'm aware of, my guess is that any if your systems will cost 4X more and sound half as good as the Bose Premuim upgrade in that vehicle., you'd be really lucky. Only based on my experience with 200 hundred after-market systems (IASCA judge) and perhaps 400 OEM systems between 'prototype' and ":sold directly to the public." OH OH! I GET TO SAY IT! "No Highs, No Lows, Must be Bose!" narcolept ----- man. if eddie was installing stuff that only sounded half as good as bose, he would've been outta business 29.6 years ago. Sure. But you are an amateur with regard to acoustics and room acoustics. Your insults are pretty meaningless... I have probably spent more time in ROOMS and especially CARS with RTAS and test equipment than you have.... Reguardless to that fact which may or may not be true... I have obviously spent ENOUGH time to not be called an amateur... So prove it; tell us something that is based on fact and not your biased opinion. Plus, the defintion of an Amateur would certainly be if I got PAID! And trust me I have been doing this kind of work professionally for nearly 30 years... Before that my love of audio was certainly of an amateur nature, but still probably more advanced than the average amateur.... I'd agree that the qualifier `"paid" isn't interesting. Your statements about ME being an AMATEUR are obviously manfested by you because of some inadequacy you might have or some jealousy or .... Heck I dont know why you are making up these insults... Everyone here knows me, some of them say I have been doing this sort of work longer than dirt has existed.... Actually it seems like you are probably accomplished in installation but acoustically you are not in the ballpark. You seem to unaware of the acoustc benefits of the car cabin (assigning those benefits to customers as directional effects) transfer function. Your insults are only affecting your own credibility in this issue Insults? That's your BAG Eddie. You just will not discuss acoustics. I'm guessing that's because you aren't conversent in them. But, I'll talk/chat to anyone who is inerested. Along with your inability to produce any evedence Oh, and your statements about turning a woofer box backward in a car wont make any difference to the woofer sound in the car... Eddie Runner http://www.installer.com/tech/ So Eddie; tell me again exactly how any given woofer with a known displacement in a given enclosure in a known space with a given amplifier can "decide" to make more SPL" when faced in one direction or another. PLEASE Double PLEASE. I 'know' I'm stupid; but please tell me and everyone else how we're wrong. |
#147
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Actual tests - aiming woofer boxes
OK, finally a little REAL meat and potatoes..... Thanks for that Tom.
I believe instead of always using terms the layman probably doesnt know and many pros use incorrectly its always best to lay out the definitions. I have done so already on my understadning of pressure fields and standing waves and so far I have seen no pro or con from you specificly on those definitions. The AXIAL MODE you talk about here are really a combination of the complex reflected waves (really an infinite number) and the incident wave as they interact in a closed space, not only just standing waves but also resonances of the space itself... THIS IS GOOD Tom! But if you would please take the time to look at my cartoon page http://www.installer.com/tech/aiming.html you might want to notice that my example in the hope of keeping it simple I have eliminated the INFINITE amout of reflected waves and kept it simply to one direct wave and one reflection.... We all know there is alot more going on than simply one reflected wave, but if you read my text you will see I plainly say that the page is very simple and just a starting point for ayone that wants to experement further.... Obviously all the reflections and resonances that have to be there to cause the AXIAL NODE you love so much would me quite a bit more complex than I wanted to go in that paper... I dont thinks its very fair of you to DIS my paper and throw around the AXIAL MODE stuff when it is too simple to even worry about the axial modes at this point.... Remember this paper is for kids to get the basics, not professors to teach advanced accoustics. Typicly and in your example, the MODES are created from bounced waves from multiple directions and are NOT simple ONE standing wave, they are combinations of many standing waves and the superpositioning of the waves creates the nodes and antinodes to not be placed in the 1/4, 1/2, 3/4, 1 (and so on) wavelengths but at shorter distances. IMO, its best to have a good grasp on standing waves BEFORE you delve into the interaction of the multiple standing waves and MODES of an inclosed space.... Although I think alot of accoustics guys may rarley break down the accoustic phenomenon into its simplest elements as I do in the cartoon. Now, on your definition below, you say: In this example there wil be pressure gain in the room below 26 Hz (@ 12 dB per octave as freq falls) assuming little structure dissapation. I find that a little condecending that you can claim there is a 12dB per octave rise but you pick on my charts and claim the higher SPL cannot happen and SPL just cant come from nowhere... With your background I know that you must know that higher (or lower) SPLs can come from in phase or out of phase reflections or resonances or whatever, so your words to me must have just been looking for a fight or something. Also, I dont think the magic 1 octave rise you describe is a good number, car/truck/suv interior sizes vary soo much it would not be prudent to ASSume 1 octave on every vehicle. And my sweeps definitly do not show your theory on this to be true if we assume 60Hz is the spot. Also, I dont quite get it when you so far surpass my simple standing wave paper with one reflector and go into AXIAL MODE and you completely ignored the tangential mode and so much more of the resonant modes that might make more sense in a car... Axial mode is not 3D like you would have in a completely close space. its also my opinion that you can calculate this in a rectangular room with some degree of accuracy but its much harder to calculate in a car that is typucly far from be ing a rectangle! I say why calculate, sweep it and see without wasting time on the math! Eddie Runner Nousaine wrote: Define LOWEST AXIAL MODE! Sure; in given acoustical space the room dimensions set-up standing wave patterns at low frequencies related to the dimensions of the space. Standing waves form at all frequencies between any two opposing surfaces. In a 6-sided enclosure (like your living room, your car and a phone booth) there are set of standing wave patterns according to frequency. In a living room of 22 X 12 X 8 feet there are natural 1st order standing waves that will occur at 26 Hz, 47 Hz and 71 Hz. There will also be 2nd harmonics at 52 Hz and 94 hz in the range below 100 Hz. In this example there wil be pressure gain in the room below 26 Hz (@ 12 dB per octave as freq falls) assuming little structure dissapation. These natural modal frequencies affect the propagation of bass in the room. That example represents a good distribution of modal effects. In a car, everything is shifted down an octave due to the decreased "size" of the space. In a smaller car, like a Corvette, Camaro, Spirit, Acura Integra or Probe the "turnover" frequency is 60 Hz as compared to 26 Hz. Subsequently the 'standing wave region' (the octave above where pressure gain occurs) is shifted up about an octave. So in a car the standing wave region lays between 60 and 600 Hz; whereas in the 2650 ft3 room it lays between 30 and 300 Hz. Anything below those frequencies is in the pressure zone where the driver displacement directly pressurizes the space (assuming enough stroke/piston area to make some sound.) Accordingly at higher frequencies where room modes (standing wave frequencies) are statistically dense (you can hear the standing wave of a 1 kHz sine wave --- 1 foot wavelength ---- by moving your head from side to side. But, that effect occurs pretty evenly distributed in the room. IOW you hear the same effect no matter where you sit. However at lower frequencies with longer wavelengths (50-feet@20 kHz) these effects come with an unequal distribution of sound pressure depending on listener location. Any more questions? |
#148
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Measuring audio bandwidth
Nousaine wrote:
Hogwash; you'd never even done confirmation of your affirmations prior. ??? Can you prove this accusation ??? I can prove I have has access to frequency generators to do sweeps with as far back as the 70s... So why would you doubt me enough to call me a liar on a public forum??? Just bad manners? Worried about something?? Oh really; you'd done this before but had never archived it? And never validated your cartoons with data? As I have. I started saving sweep data on an Apple II computer input manually by the keyboard one frequency at a time back in the late 70s. I published some of this old sweep data on my computer BBS back in 1982 but I really dont know what happened to it all over the years... Do you expect me to still have ever sweep I have ever done? ha ha ha What are you so defensive about? But why do you continually avoid the basic questions. Exactly HOW does a woofer/amp system generate MORE sound pressure when faced in a given directionn when there's NO sound pressure variation relative to the space it's in? No boundary interaction? How? Please!!! Simple http://www.installer.com/tech/aiming.html http://www.installer.com/tech/aiming2.html Can you recall (unpublish it) that crappy article you wrote thats full of lies or is it too late for that??? What "lies" have you found? Please be explicit. I havent read your article in some time, but I remember it saying that placement of a woofer in a car is not important and that placement of the woofer will not affect the woofers performance.... paraphrased of course. My sweeps and other evedence known by nearly every kid with a woofer in his car contradicts your article. (if I remember it correctly) Bull****. I just mentioned that the effects you were claiming didn't fit with the current las of physics the rest of us live with on a day-to-day basis. I know what you say but it appears your wrong.... sorry... EXACTLY how does a woofer systen KNOW it's supposed to generate MORE SPL in a given space depending on whichj direction it's facing? I could ask you the same question when you claim your woofer rises 12 dB per octave after your first axial mode... ha ha We know that SPL can increase or decrease if reflections are in phase or out of phase or at a resonant point so your crap above about the *HOW DOES THE WOOFER KNOW* is not fooling anyone... (why waste our time on this stuff?) Acoustic cancellations? Why don't we see ANY below 80 Hz in your data? Didn't your "cartoon" show large effects at 60 Hz? What's the deal here? I see em! http://www.installer.com/tech/aiming2.html other folks say they see em! Why cant you see em? Are you actually looking at my sweeps or are you just trying to imagine what you think they look like?? You asked for it.... You're right and I'm dishing it out too. Is that what you call it??? ha ha ha Why can't you answer basic physics questions? I have How does your cartoon explain "standing wave" effects when the sound "waves" are traveling in the SAME direction? I answered that yesterday. a standing wave can occure no matter which way the interacting waves are traveling... Why do you thinik a standing wave is limited to opposing waves? They can in fact interact and create nodes and antinodes if the waves interact a opposing waves or waves crossing each other or even traveling together for some time.... Help me he does not the wave pattern you show depend on the reflection coming "back" to the direct sound and traveling in the same direction as the original sound beyond the point of incidence? No???? Help us here. Yes you must need help... Now I know exactly the acoustics hee; but you apparently do NOT. So why not step into some more bull****. It seems you like that environment. Whatever you say... Its pretty hard to carry this conversation any further with you... My web pages are going to stay as they are unless I add more to them, I am sorry that they are so much at odds with your previous papers and you dont wish to discuss things rationally... Eddie Runner |
#149
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Measuring audio bandwidth
Soundfreak03 wrote:
Oh really; you'd done this before but had never archived it? And never validated your cartoons with data? As I have. Why would he need to archive it? I do sweeps and graphs of rooms using Smaart all the time but I dont archive them. Tom Nousaine wont produce any evedence so all he can do is try to run me into the ground on any and all subjects at hand. This guy is a nutcase so dont hurt strain yourself on my account. Eddie Runner |
#150
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Who is confronting who? ALL RACers are morons?
Nousaine wrote:
Tom, just because you have PUBLISHED something doesnt mean your a badass! Sure, but he made agressive statements which he obviously hasn't confirmed otherwise himself. Thats just the way Liz is, and I wouldnt be so quick to DIS what Liz does or does not know since you really dont know him.... Are you under the impression that EVERYONE here on RAC is a moron? It seems like it since you are so quick to DIS anyone that talks to you without actually knowing anything about who you are talking to.... Liz is still a newbie to me but he has actually made some pretty decent contributions to this newsgroup in the past ... I have read 100s of articles in the car audio and home audio magazines that were full of bull****.... Sure; and some of the stuff on your website about acoustics is a good point of reference. You keep saying that. Why does my stuff bother you so much??? A little insecurity maybe?? Sure; and about 30% of it falls directly in line with the Urban Legends published on YOUR website. can you be more specific or are you just looking for anyway you can to DIS me like you did Lizard and everyone else on this newsgroup?? Just because Liz didnt tell you his publishing credentials before he said he belived me more than he believed you doesnt mean he has to have credentials that include publishing stuff... OK but why did he come with full-battle gear on? Loud-mouth bluster isn't a reasonable discussion technique in my world. Given your 'discussion' style I'd guess you like it. You talk about Lizards loud-mouthed bluster...??? Look at your own in this very same post!!! So tell him next time that IF he has a good argument to step right in. But, if he only has a 'bull****' argument he should expect to be confronted at he gate. So you think YOU are confronting Lizard about his bull****!??? I think most folks reading this would read it as Lizard (and a bunch of other people) confronting YOU..... These folks know for a fact that moving thier woofer boxes DOES make a difference! When you say all these people are imagining the phenomenon I dont blame them about confronting you.. Like Liz did.... How can you think you are confronting him???? ha ha ha Eddie Runner http://www.installer.com/tech/ |
#151
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smack
Nousaine wrote:
Loose tolerances? I'm guessing that you must know Eddie then. ouch! |
#152
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smack
Nousaine wrote:
My advice is to investigate any offers from Eddie about bridges in Arizona. ouch! |
#153
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tits
Nousaine wrote:
Isn' tit intersting Now your talkin! |
#154
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Where is it Tom?
Nousaine wrote:
Actually I've done all those measurements before. well, whats wrong, did you not archive your data??? Where is it..? ha ha ha |
#155
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The woofer KNOWS!
Nousaine wrote:
What I'm asking is exactly "how" a given woofer system placed in a car with no obvious frequency response deviations KNOWS that it's SUPPOSED to have more output when it's facing to the back??? Why are you even trying to go here Tom.... THis is one of the most rediculus questions I have heard... |
#156
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Tom is Unclear
Nousaine wrote:
Look carefully at the graphs, There are some differences, and there are some spots where there are no differences, and spots with constant differences over several Hz .... Bull****; what frequencies; what differences? Look at the graphs!!! http://www.installer.com/tech/aiming2.html I can see it Everyone else can see it Why cant you see it Tom? I've done all these experiments multiple times over the years. That's why I know that Eddie Runner is full of bull**** on this issue. If you say so, We still dont see your data... Maybe its EL-NINO ha ha ha All of these experiments are easy to replicate; ....but Eddie has just started to investigate them. A-bout time; I'd say. Another lame attempt to make me look like a newbie... Tom is so jealous of me.. ha ha ha poor fellow, it must suk to be him. |
#157
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Tom flips a coin
Nousaine wrote:
So? So has Amar Bose. and the point of that is what? Although I've not listened to any of your 'systems' that I'm aware of, my guess is that any if your systems will cost 4X more and sound half as good as the Bose Premuim upgrade in that vehicle., you'd be really lucky. Oh so you want to DIS the systems I have created and you have never even heard any of them... Doesnt bother me... Only based on my experience with 200 hundred after-market systems (IASCA judge) and perhaps 400 OEM systems between 'prototype' and ":sold directly to the public." Iasca Judge? Is that supposed to impress me? I have been a judge more times that I can count, including judge at the very first world finals.... Dont forget (or maybe you dont know) the JUDGING and the contests started right here in Houston so I may have had a little more influence in how so many of todays contests eveolved that you might know... Why are you so quick to DIS everyone and everything before you even know anything about them??? So prove it; tell us something that is based on fact and not your biased opinion. My sweeps are my proof http://www.installer.com/tech/aiming2.html I get the feeling if we flipped a coin and you saw it was heads, you would yell at me to PROVE IT.... Here ya go http://www.installer.com/tech/quarter.bmp Eddie ha ha ha |
#158
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Bose good one!
ha ha ha ha
havent heard that one in a long time! Good one! still laughing narcolept wrote: OH OH! I GET TO SAY IT! "No Highs, No Lows, Must be Bose!" |
#159
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Standing wave definition explained
Nousaine wrote:
But you made a big issue of standing waves needing 2 sound waves traveling in 'different directions'. Since youve saved all our posts for the last year why don't you look up what you said? I just looked and I never said that pertaining to my web page http://www.installer.com/tech/aiming.html your must be mistaken And then you've not had the balls to convincingly explain exactly how your 'cartoon' that has 2 sound waves traveling in the "same direction" can cause a standing wave 'cancellation.' Soud waves to not have to be moving in opposite directions for a standing wave to occur... I have explained all that before and you act like you have never seen me say that... I used to know a guy that would get real drunk and then wanna talk tech with me, then the next morning he would be sober and not remember anything we talked about.... Are you drunk Tom?? Eddie I dont drink |
#160
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Finally TOMS evedence....!!! Read this one if no other!
Nousaine wrote:
My "evidence" is looking at your cartoon and looking at your defintion of standing waves and wondering "how" they jibe. So, is that all you can offer us?? |
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