It's undoubtedly the program, in modern terms I am just a hack. That I could get anything to work "over-the-net" amazed even me! How one would go about debugging something like that I have absolutely no idea. Polar_map is a dead end because of what I am doing now. I found the development environment so appealing that I jumped into a project that is so complex that I had resisted doing it for years - for good reason. It would not have been possible without .Net. What I am doing now will allow anyone to create those kinds of polar maps with a simple home setup. What I posted requires MathCAD interface to cruch the data and its very clumsy. What Polar_map is now is only one of multiple features of the new software.
OK, then let me put it another way.
HTML img tags have an alt field. Although it was mostly to help text browsers, it is also used for accessibility and gives something to read whilst our images download, i.e: it protects the resource from breaking. Respectfully, in your case this would mean putting up the original still images.
HTML img tags have an alt field. Although it was mostly to help text browsers, it is also used for accessibility and gives something to read whilst our images download, i.e: it protects the resource from breaking. Respectfully, in your case this would mean putting up the original still images.
I'm sorry, I don't follow. I know about the "alt" field, but I don't do much with it because nothing on my site takes any time to load - at least not for me.
EDIT! Something crossed my mind and I checked. I had forgotten that I had taken down the original images for the speakers. So now I follow your comments. It was my intention to have BOTH a static image and the link to the program. I just have not gotten arround to doing the static images.
But I do appreciate your concern now and thanks for pointing out this mistake. I had forgotten where I was in the process.
"I'm too old for this."
EDIT! Something crossed my mind and I checked. I had forgotten that I had taken down the original images for the speakers. So now I follow your comments. It was my intention to have BOTH a static image and the link to the program. I just have not gotten arround to doing the static images.
But I do appreciate your concern now and thanks for pointing out this mistake. I had forgotten where I was in the process.
"I'm too old for this."
Dr. Geddes' program isn't something that renders in the browser. It's actually a fully fledged application that runs on your machine like MS Word would (it just uses a different installation mechanism). It doesn't render in the browser at all. It requires the .net frame to be installed on the machine to launch and I think only IE can launch it. It's an idea Microsoft had for the .net framework a long time ago. People would write applications to run client side, that would be launched through IE. So the developer could make improvements, and the next time a user launched it, it would simply download the app again and the user would have the changes. I'm not aware of any major applications written to use it, and I'm not sure Microsoft touts it anymore, they've moved on to Silverlight.
He should be able to compile it to an exe such that it would run fine through wine on linux. A little effort and he could compile it to work on a Mac too.
Writing Mac OS X applications with Microsoft Visual Studio Express - MacCentre701
I don't see .net being the future though. Especially not client side one click deploy .net applications. .net will still remain a major development platform player, but I see everything shifting to HTML5 (including the .net framework, Mircosoft will just be a few years behind as usual). The demo of Quake2 playing in a browser using HTML5 is very impressive. Eventually the idea of a desktop computer is going to disappear. Our desktops will become internet thin clients, and your OS and all applications will live on servers out on the internet. Not going to happen in the next year or two, but ~10 I'd bet on it.
Google's Chrome OS and their announcement a week ago or so that they were dropping Windows from their organization entirely are Google's first major public steps in this direction.
He should be able to compile it to an exe such that it would run fine through wine on linux. A little effort and he could compile it to work on a Mac too.
Writing Mac OS X applications with Microsoft Visual Studio Express - MacCentre701
I don't see .net being the future though. Especially not client side one click deploy .net applications. .net will still remain a major development platform player, but I see everything shifting to HTML5 (including the .net framework, Mircosoft will just be a few years behind as usual). The demo of Quake2 playing in a browser using HTML5 is very impressive. Eventually the idea of a desktop computer is going to disappear. Our desktops will become internet thin clients, and your OS and all applications will live on servers out on the internet. Not going to happen in the next year or two, but ~10 I'd bet on it.
Google's Chrome OS and their announcement a week ago or so that they were dropping Windows from their organization entirely are Google's first major public steps in this direction.
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For those of you making bets, I would not bet against MS. When you are the king of market share you are never "first to market" - it makes no sense. That's what the small guys do. But you do make sure that you select from the "bleeding edge" those technologies that work best. MS is ALWAYS late, and always will be - exactly what I would do in thier situation. No one, and I repeat, no one, has the market clout of MS. In the PC business Apple isn't even a player, they make their money on phones and MP3 players. In PCs they basically loose money.
I have some inside info on Google and I wouldn't bet them against MS in the long run.
Dustin is right that it is a client side app using "one click" and sucessful or not its embedded in Visual Studio and without it others would never see this program at all, IE or otherwise. So as far as I am concerned its a God-send. There is no mention of Silverlight in Visual Studio 2008.
What people don't realize is that a great portion of this program is written in FORTRAN. Yep - thats right. Now would anyone believe that a FORTRAN app could be run from the web!? I certainly wouldn't have. And there is no way that its going to run in Mac OS since the FORTRAN compiler doesn't support Mac. I don't know of any that do. Linux, yes, but not Mac.
I have some inside info on Google and I wouldn't bet them against MS in the long run.
Dustin is right that it is a client side app using "one click" and sucessful or not its embedded in Visual Studio and without it others would never see this program at all, IE or otherwise. So as far as I am concerned its a God-send. There is no mention of Silverlight in Visual Studio 2008.
What people don't realize is that a great portion of this program is written in FORTRAN. Yep - thats right. Now would anyone believe that a FORTRAN app could be run from the web!? I certainly wouldn't have. And there is no way that its going to run in Mac OS since the FORTRAN compiler doesn't support Mac. I don't know of any that do. Linux, yes, but not Mac.
The app is not an HTML app, so how could it run in a browser? Whatever the future may bring regarding standards, the fact is that the App does not run in a browser. And even if it "could" be made to run in a browser, I not about to learn all new programming techniques to make that happen. I do not see the point in agruing what it "could be" versus what it "is". My job is not programming web apps, but clearly one of my major expertises is "numerical methods in acoustics". I do not ever see major engineering software running as a browser app, I just don't think that makes sense (the browser being the interface "terminal" to a server app, maybe, but the app will still be running in a higher level language than HTML. Client - server programming is beyond my expertise however.)
So to be more specific - try programming a Fourier Transform or Singular Value Decomposition in HTML. These techniques only exist in C++ and FORTRAN, with FORTRAN being by far the more efficient. Its an interesting story about why Intel bought the FORTRAN compiler from HP when HP wanted to cancel it. Its because INTEL has so much internal critical software written in FORTRAN than they needed to maintain an efficient compiler, and what they offer is by far the best FORTRAN compiler that has ever existed. Let me give you an example. In my program there are two large 2-dimensional complex matrices that need to be multipled together. In FORTRAN that code is one line of three variables like A = B*C and, the best part is, that the compiler parallelizes the computations running it on as many processors as are available to the system. No other language does this. No other language even comes close. In C++ this requires the coder write seperate threads for each processor - a monumental task and C++ does not have a native Complex Data type. I don't think that any other language could even do the problem. I know that VB.Net can't.
So to be more specific - try programming a Fourier Transform or Singular Value Decomposition in HTML. These techniques only exist in C++ and FORTRAN, with FORTRAN being by far the more efficient. Its an interesting story about why Intel bought the FORTRAN compiler from HP when HP wanted to cancel it. Its because INTEL has so much internal critical software written in FORTRAN than they needed to maintain an efficient compiler, and what they offer is by far the best FORTRAN compiler that has ever existed. Let me give you an example. In my program there are two large 2-dimensional complex matrices that need to be multipled together. In FORTRAN that code is one line of three variables like A = B*C and, the best part is, that the compiler parallelizes the computations running it on as many processors as are available to the system. No other language does this. No other language even comes close. In C++ this requires the coder write seperate threads for each processor - a monumental task and C++ does not have a native Complex Data type. I don't think that any other language could even do the problem. I know that VB.Net can't.
I believe that I have solved the biggest concern. Thanks AllenB for making me aware of this flaw in my website. I had forgetten to complete what I was doing.
A static picture of each system is now shown on the web page for each system and people with the right access can still run an interactive one. The format for all of the data pictures (mine and others) is now the same, which was a major goal of this whole thing. We can now compare many different systems is a standard format that makes these comparisons relavent, unlike the previous situation where there was no compreshensive data set available which could be compared across different designs.
A static picture of each system is now shown on the web page for each system and people with the right access can still run an interactive one. The format for all of the data pictures (mine and others) is now the same, which was a major goal of this whole thing. We can now compare many different systems is a standard format that makes these comparisons relavent, unlike the previous situation where there was no compreshensive data set available which could be compared across different designs.
Here is the text from my post. Let's see if it works.
I see from this thread that people were asking questions about the setup in my BMW. Here are some answers to your questions.
First, my dissertation was on a constant beamwidth, wide bandwidth array and had nothing to do with my car. JBL was nice enough to send me a bunch of speakers to use in the array though. I think it is cool that some of your have actually found and downloaded it btw.
No, I don't work for Harman. I work for this company ETS-Lindgren | EMC and RF Microwave Testing, Measurement and Shielding We build test chambers and I do all of the chamber design for the acoustics side of the business - anechoic chambers, reverberation rooms, noise control rooms, studios, audiometric rooms, etc.... So I live primarily in the industrial test and measurement world. If you are ever in the Austin area, send me a PM and I can give you a tour of our factory and our lab. We have a very large hemi-anechoic chamber with a >0dBA noise floor. Nice and quiet in there. Anyway, on to the 2118 setup I ran.
So the 7 series is no more. It was in a fire at Audio FX in Georgetown, Texas. Some of the equipment was recovered and I was able to save the diffraction rings for the mids. I gave them to someone in Florida with a Civic as long as he promised to be nice to them. That was a few years ago.
No this was not part of a thesis and was never published. I lost all of my test data when my old school pc died and don't have a need/desire to test again. I have the math and my notes somewhere but no promises on finding that and posting.
Yes, it what Gary used in his Regal, but due to the crossover points and size of his mids, it was more for points that sound. The technique I used only works when trying to mate a large speaker with a tweeter. If I had the room, I would have run the 2118 with a 2105 and then the Scan tweet, but I did not have the room. So unless you are going to run an 8 in a 2 way setup, don't waste your time trying this.
Now for the educational portion of the program....(no math)
If you look at sound radiation from a baffled piston (loudspeaker), you will see a relationship between loudspeaker diameter and wavelength as they relate to beamwidth. As the wavelength approaches the diameter of the piston, the main lobe narrows and side lobes appear. Now that is a simple algebraic relationship and nothing in acoustics starts out as a simple algebraic equation. It starts with differential equations with certain boundary conditions. One of the boundary conditions is that the edge of the loudspeaker in not clamped, which is what you have with a loudspeaker that moves freely at the edge. The other boundary condition is that the distance from the center of the loudspeaker to the edge of the loudspeaker is constant. It is this condition that determines loudspeaker beam patterns. If you are at a point directly in front of a speaker (say 1 m) and measure to the center of the dust cap, you get a distance of 1m. Now if you measure from the same point to the edge of the cone, you get a longer measurement. The difference between the two is the key because that difference if the same for any point at the edge of the cone. When the speaker moves (assuming pistonic motion), a wave front appears about the surface of the cone and travels toward you. The wave motion from the center of the cone gets there first and the wave from the edge (called the edge wave) gets there a little later. This difference or delay is also a phase shift. When you combine both waves at your position, they can combine constructively and destructively depending on the amount of delay. If the wave length is very large, there is little or no change in the directivity. If the difference is on the order of a wavelength, then you get interference and the beam pattern changes.
Now, if the edge of the loudspeaker is random, then the interference is reduced and the beamwidth stays omni-directional at higher frequencies. Also, the side lobes, when they appear, are 27 dB below the main lobe in amplitude. Since it is hard to build a random edge woofer and make it work well, you build the next best thing – a lens or diffraction ring as I call it. Of course, if you do the math you will see that an 8” speaker is good to about 1 kHz before you need this. My 8s play to almost 3 k so I need a ring. When you get to a 6”, you are at ~3k before this would do you any good so it is not necessary. They work for me because I go from an 8 to a tweeter. If you put them on anything smaller, they are not worth the effort.
I have to give credit where credit is due on these. Gary Biggs helped me make mine. Actually he made them because my aluminum skills at the time were not so hot. I did polish them myself though.
So....who wants to see a picture? I would like to post one.
Feel free to ask questions, but I don't spend much time on forums. So send me a PM if I don't reply.
-Doug
In a previous post Geddes mentioned the possibility of using a waveguide mouth with an irregular shape to break up the dip in the response. Here's a similar idea which was used by Douglas Winker, who used to work for Harman iirc. The original post is here:
DIY - reducing speaker beaming - Page 2 - DIYMA.com
Winker used it to extend the upper frequency response of an 8" woofer, but the idea is similar. It seems like this might be useful with the woofer if it's intended to be listened to off axis. (Like these speakers are.)
For those of us who can't see your undoubtedly interesting program - I think you might be underestimating the number of people into high-performance speakers who prefer OSX - any highlights? What model was the Behringer?
FFT can be done in about anything, though not always very efficiently. I've seen FFT subroutines in Visual Basic even. There are some very fast FFT algorithms for Pascal/Delphi (which I use). It can't do the multiprocessor trick, though, at least not with the code I've used.
If using .NET compilers, all the languages reduce to one underlying language, the .NET common runtime -- VBasic,Net, C#.net, Delphi.net all are just dialects in that situation. I don't know whether there's a Fortran.NET.
I don't remember the model number. How many small powered Behringer two ways are there. I don't understand "prefer OSX". The argument over OS's is not going to go away over this issue. No matter what you do someone is unhappy.
I searched for VB6 FFT implimentations and couldn't find any. I saw that there was a Java one. What about Singular Value Decomposition? FFTs are trivial by comparison.
The FORTRAN is not .net, but does run in the same IDE and uses the same debugger so the difference is transparent (albeit no Managed Code). It does not compile to the common language of .Net, but compiles down to assembler, which is, of course what makes it non-transportable. But its also what allows for lightning fast implimentations especially when running on Intel chips. The compiler knows all about how to optimize for Intel's strengths. From what I understand virtually all of the large FEA packages use this compiler for the number crunching. FORTRAN is obviously not GUI capable (although it can do COM.)
Yes this is very similar to my comments. But the quoted statement above is incorrect. The random edge will remove any "coherent effects" such as an axial hole, or lobes, but in general the beam width stays the same. This can be proven from in a number of different ways, but that will be left to the reader.
the "Truth" series?, size?, ported, kevlar, ribbon? I assume biggest woofer "small monitor" is better for directivity integration?
looks like "Eurolive" series also has a elliptical waveguide w/12" woofer...
BEHRINGER: Products
looks like "Eurolive" series also has a elliptical waveguide w/12" woofer...
BEHRINGER: Products
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Yup. In my day (home office) job, I use an FFT routine to look at stock market data in Tradestation's 'Easy Language', which has its roots in Pascal.
Automated Trading System & Platform - Tradestation