I would like to see ANYONE post a design for a tapped horn that has 7 db of gain across the entire bandwidth of an equivalent sized "optimally flat" vented enclosure (VRC =VAS, Tuning =FS), in an enclosure no larger than said vented box.
Shoot... show me 4 db over the same bandwidth as an "optimally flat" vented enclosure with a tapped horn of size no larger than the vented box.
Shoot... show me 4 db over the same bandwidth as an "optimally flat" vented enclosure with a tapped horn of size no larger than the vented box.
Graphics Design Program Needed
You need to migrate the points into a graphics program expressed as a set of geometric elements, such as a splines, polylines, etc.
There are many ways to do this, here is two briefly described:
Using a spline command in any decent graphics design program, such as AutoCAD, you can create a horn profile that may be plotted to any scale desired.
To automate creation of the set of macro commands needed, read the (x,y,z) points into Excel and then use string formula to create the individual commands with the point data imbedded.
Once you setup of the spreadsheet it can be reused with little modification.
If you are VBA wise, you can create Excel User Defined Functions to generate the individual macro commands. Then read these commands to a text file that can be executed by a graphics program.
With a little more study, a program may be written directly in the macro language of the graphics program to process the text file of (x,y,z,) points directly.
Regards,
WHG
You need to migrate the points into a graphics program expressed as a set of geometric elements, such as a splines, polylines, etc.
There are many ways to do this, here is two briefly described:
Using a spline command in any decent graphics design program, such as AutoCAD, you can create a horn profile that may be plotted to any scale desired.
To automate creation of the set of macro commands needed, read the (x,y,z) points into Excel and then use string formula to create the individual commands with the point data imbedded.
Once you setup of the spreadsheet it can be reused with little modification.
If you are VBA wise, you can create Excel User Defined Functions to generate the individual macro commands. Then read these commands to a text file that can be executed by a graphics program.
With a little more study, a program may be written directly in the macro language of the graphics program to process the text file of (x,y,z,) points directly.
Regards,
WHG
Hoisted
No they are not wrong!
Your example has a usable bandwidth of less than a decade. Question: how would you make it wider? Semantics is a petard that hangs both ways.
Regards
WHG
No they are not wrong!
Your example has a usable bandwidth of less than a decade. Question: how would you make it wider? Semantics is a petard that hangs both ways.
Regards
WHG
Yes, wrong. Any design that does not use one side of the cone as a direct radiator is going to be bandwidth limited to about 3 octaves max.
The amount of bandwidth shown is pretty average for a tapped horn with 25 hz tuning. You could get more bandwidth by making the flare longer, tuning lower. Although at some point you're going to get somewhat of a rising response and the practical limit is about 3 octaves.
IF you are willing to use one side of the cone as a direct radiator and the enclosure doesn't produce too much resonance that screws up the direct radiation then your bandwidth is limited only by the driver's own bandwidth limitations on the high end and you can get several octaves out of it, but that has nothing at all to do with this conversation about horns.
This is dead simple. In a tapped horn or front loaded horn you have a few impedance peaks to play with. The size of the enclosure will determine the strength of the resonances and the flare shape and length (and chambers in flhs) will determine the spacing between them. If there is no limit on the enclosure size you can have MASSIVE amounts of gain, and you can achieve this gain over the entire practical limit of about 3 octaves. Sure, if you place the resonances closer together you will get a bit more gain over a bit less bandwidth but the enclosure size is orders of magnitude more important in determining efficiency than bandwidth is.
For example you can take this same driver, same tuning and put it in a tiny tapped and get exactly the same bandwidth. You can't get much more out of it no matter what you do unless you change the tuning. So size controls efficiency.
I can't imagine any horn related scenario where this is not true.
The amount of bandwidth shown is pretty average for a tapped horn with 25 hz tuning. You could get more bandwidth by making the flare longer, tuning lower. Although at some point you're going to get somewhat of a rising response and the practical limit is about 3 octaves.
IF you are willing to use one side of the cone as a direct radiator and the enclosure doesn't produce too much resonance that screws up the direct radiation then your bandwidth is limited only by the driver's own bandwidth limitations on the high end and you can get several octaves out of it, but that has nothing at all to do with this conversation about horns.
This is dead simple. In a tapped horn or front loaded horn you have a few impedance peaks to play with. The size of the enclosure will determine the strength of the resonances and the flare shape and length (and chambers in flhs) will determine the spacing between them. If there is no limit on the enclosure size you can have MASSIVE amounts of gain, and you can achieve this gain over the entire practical limit of about 3 octaves. Sure, if you place the resonances closer together you will get a bit more gain over a bit less bandwidth but the enclosure size is orders of magnitude more important in determining efficiency than bandwidth is.
For example you can take this same driver, same tuning and put it in a tiny tapped and get exactly the same bandwidth. You can't get much more out of it no matter what you do unless you change the tuning. So size controls efficiency.
I can't imagine any horn related scenario where this is not true.
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Here's an example in picture form. I didn't want to spend too much time on this so I used front loaded horns and I used the Hornresp default example. I changed the Ang to 2pi because the default is already a full size ideal horn in .5pi and I needed an undersized horn for this example.
Top row left - Hornresp default design in 2pi space
Top row right - Same driver but I used "System design - With driver" to create an ideal horn with same flare frequency as the second half of the default design, and with 1 decade of bandwidth
Second row - schematic of both designs, the ideal full size horn is not quite 4x larger than the default design
Third row - FR of both designs at 2.83V
Fourth row - efficiency of both designs
Clearly you can see that the large full size ideal horn has MORE bandwidth at BOTH ends and BETTER efficiency across the board, not the other way around as stated. Again, size controls efficiency and bandwidth doesn't have much to do with it. I could make a MUCH more dramatic example if I started with a smaller horn than the Hornresp default design but I didn't want to spend more than 5 minutes on this and I didn't want to have to defend the quality of the example horn.
The full size ideal horn in this example is not exactly practical for a few reasons but it is still a good example.
Top row left - Hornresp default design in 2pi space
Top row right - Same driver but I used "System design - With driver" to create an ideal horn with same flare frequency as the second half of the default design, and with 1 decade of bandwidth
Second row - schematic of both designs, the ideal full size horn is not quite 4x larger than the default design
Third row - FR of both designs at 2.83V
Fourth row - efficiency of both designs
Clearly you can see that the large full size ideal horn has MORE bandwidth at BOTH ends and BETTER efficiency across the board, not the other way around as stated. Again, size controls efficiency and bandwidth doesn't have much to do with it. I could make a MUCH more dramatic example if I started with a smaller horn than the Hornresp default design but I didn't want to spend more than 5 minutes on this and I didn't want to have to defend the quality of the example horn.
The full size ideal horn in this example is not exactly practical for a few reasons but it is still a good example.
An externally hosted image should be here but it was not working when we last tested it.
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Yes
You example clearly demonstrate that the product of band-width and efficiency is not a constant here. The area under the curve for the larger horn is commensurately larger. I am not often surprised here, but your point is well taken.
Regards,
WHG
You example clearly demonstrate that the product of band-width and efficiency is not a constant here. The area under the curve for the larger horn is commensurately larger. I am not often surprised here, but your point is well taken.
Regards,
WHG
Actually, after looking at it for a few minutes I realize it's a very bad example and terribly unfair, the difference in low end efficiency in this example is due to rear chamber size, not enclosure size. The Hornresp default horn is not a good example horn, it doesn't seem possible to make an ideal full size horn for that driver with a reasonable rear chamber size. I guess I should have spent a bit more than 5 minutes on it. I'll try to post up something more reasonable a bit later.
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Ok, sorry about that, I think this example is a lot more fair. The difference in efficiency in this one is almost completely due to enclosure size, I tried to make sure everything else was very close. You could change Vrc and/or S1 in either example horn to match the other but it doesn't change much. In this example the flare frequency and T is the same for both (so they should be covering the same frequencies).
Top row left - an undersized horn from my records
Top row right - same driver, I used "System Design - with driver" to create an ideal full size horn
Second row - schematic of both - the big horn is almost 18x larger than the little one
Third row - FR of both at 1 watt at 5.92 ohms
Fourth row - efficiency of both
Fifth row - FR and efficiency overlaid for easier comparison
Flare frequency and T are exactly the same this time so the high end bandwidth is ~ the same, but there's more bandwidth on the low end in the larger horn, as expected. Average efficiency in the larger horn is much higher, as expected, especially on the low end. Flare frequency controls the tuning frequency, flare T controls the high end bandwidth, and enclosure size controls low end extensions and efficiency, especially the low end efficiency. (Basically.)
Top row left - an undersized horn from my records
Top row right - same driver, I used "System Design - with driver" to create an ideal full size horn
Second row - schematic of both - the big horn is almost 18x larger than the little one
Third row - FR of both at 1 watt at 5.92 ohms
Fourth row - efficiency of both
Fifth row - FR and efficiency overlaid for easier comparison
Flare frequency and T are exactly the same this time so the high end bandwidth is ~ the same, but there's more bandwidth on the low end in the larger horn, as expected. Average efficiency in the larger horn is much higher, as expected, especially on the low end. Flare frequency controls the tuning frequency, flare T controls the high end bandwidth, and enclosure size controls low end extensions and efficiency, especially the low end efficiency. (Basically.)
An externally hosted image should be here but it was not working when we last tested it.
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What have I started?
Let it go guys.
As simple as I can make my "definition" which is already in my little paragraph.
If you are going for a fancy box.
That is anything other than a sealed or vented enclosure. Then to give it a horn moniker I like to see more gain in it's passband than an equivalent simple box.
Note that many tapered pipe designs have some gain. About three db.
Then people stick a driver part way down the tapered pipe and call it a tapped horn.
The argument is that it looks like a taped horn.
OK it does.
I design horns of many different types for many different purposes. And I have built more than I can even begin to count. In fact I make a big chunk of my living doing this kind of design work. Must mean either I know what I'm doing, or people like to throw money my way for fun. ( Sometimes I wonder which one it is.)
(Thanks David, it's all your fault really!)
Including real tapped horns. They are not that easy to design correctly.
Call what ever you want by what ever name you want. In my little world the names do matter. A horn has to have gain. having gain means you have a limited passband. The better the design the greater gain within the required passband. No big mystery.
I'm sorry I posted my little banter above. Lets get back to more interesting things please.
Let it go guys.
As simple as I can make my "definition" which is already in my little paragraph.
If you are going for a fancy box.
That is anything other than a sealed or vented enclosure. Then to give it a horn moniker I like to see more gain in it's passband than an equivalent simple box.
Note that many tapered pipe designs have some gain. About three db.
Then people stick a driver part way down the tapered pipe and call it a tapped horn.
The argument is that it looks like a taped horn.
OK it does.
I design horns of many different types for many different purposes. And I have built more than I can even begin to count. In fact I make a big chunk of my living doing this kind of design work. Must mean either I know what I'm doing, or people like to throw money my way for fun. ( Sometimes I wonder which one it is.)
(Thanks David, it's all your fault really!)
Including real tapped horns. They are not that easy to design correctly.
Call what ever you want by what ever name you want. In my little world the names do matter. A horn has to have gain. having gain means you have a limited passband. The better the design the greater gain within the required passband. No big mystery.
I'm sorry I posted my little banter above. Lets get back to more interesting things please.
Hi Damien,
Thanks, that would be great.
On thinking about the problem a little more, it would also be very useful for me to have a copy of your complete Hornresp.dat file (including the faulty record), if that is okay by you. The Hornresp.dat file is located in the 'Data' subfolder just beneath the folder in which you have your Hornresp.exe file.
If you like, you can send me the copy of your Hornresp.dat file as an email attachment. Simply click on the Hornresp link at the bottom of this Post and then click on my name on the Hornresp webpage to open an email message addressed to me.
Thanks again, and kind regards,
David
Ugh!
Thanks for the clarifying example. The immediate conversation here, has been brief and informative. The objections to it, reinforces my reasons for not posting here frequently. Most of the horn designs out there, are too-small for the mission that they are expected to fill, and they sound accordingly nasty as a result.
Regards,
WHG
Thanks for the clarifying example. The immediate conversation here, has been brief and informative. The objections to it, reinforces my reasons for not posting here frequently. Most of the horn designs out there, are too-small for the mission that they are expected to fill, and they sound accordingly nasty as a result.
Regards,
WHG
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Just to share everyone, i have put those files online. I just needed to use a little trick to support those type of file, changing their extension in xls :
hornresp.xls : just rename it as .dat
stupiddesign.xls : just rename it as .txt
Damien
While this statement is true.
The neat part for me is that many people are trying.
When you do something out of the ordinary for yourself there is a real and true sense of pride in the design and creation of your work.
I do not in any way want to belittle anyone's efforts.
Over the years I have been involved as a design consultant in horns the bottom line for anyone looking at making them is that there is a real life gain in output versus cabinet build complexity.
That is the sole justification for a manufacturer. More output per watt.
If you can do it in a smaller enclosure alla Tapped horn popularised by Mr. Danley is a side benefit.
But there are few tapped horns available that match the engineering prowess of what Mr. Danley has offered.
That tells me a simple truth. They are not that easy to create.
There are plenty of prior art patent examples that could smash any claims to originality in court. Dating back 50 years in some of the examples. Seriously there is very little new things in speaker design.
The ability to challenge a patent does not get you to the point that you know how to design a tapped horn.
The patents granted to Mr. Danley cover his synergy concept. That is fairly unique, although there are many examples of it in the literature as well.
His synthesis of the placement options and the tradeoffs are very well thought out. He deserves patent protection on this unique bit of engineering in my opinion.
The low frequency tapped horns are in a situation that the driver that work well in a truly optimised tapped horn are expensive versus a conventional vented enclosure. The tapped horn enclosure itself is more expensive to build than a conventional enclosure.
You quickly find out that these are businesses that are trying to make money. The designs that have the greatest return on investment are the ones that get the most traction from the marketing department.
Very often the best designs do not ever see the light of day.
The ability to challenge a patent does not get you to the point that you know how to design a tapped horn.
The patents granted to Mr. Danley cover his synergy concept. That is fairly unique, although there are many examples of it in the literature as well.
His synthesis of the placement options and the tradeoffs are very well thought out. He deserves patent protection on this unique bit of engineering in my opinion.
The low frequency tapped horns are in a situation that the driver that work well in a truly optimised tapped horn are expensive versus a conventional vented enclosure. The tapped horn enclosure itself is more expensive to build than a conventional enclosure.
You quickly find out that these are businesses that are trying to make money. The designs that have the greatest return on investment are the ones that get the most traction from the marketing department.
Very often the best designs do not ever see the light of day.