No. I just wanted to emphasize the need for terminations. I agree that its hard to terminate a conical horn (compared to constructing the basic pyramid) but I think its worth the effort
If the original poster maLx is still here: you can skip over the complicated discussions above.
The take-home lesson of the last 15 (ish) posts is that a conical horn will sound a bit better if you put a bit of a curve at throat and mouth, like in the picture. The larger and smoother you can make the mouth curve, the better it will be... but too big gets awkward, obviously.
The DIY project I linked in post 9 is, IMO, a good example + fairly easy to replicate (or do a smaller copy).
Klipsch K402 replica build - DIY Audio Projects - StereoNET
The take-home lesson of the last 15 (ish) posts is that a conical horn will sound a bit better if you put a bit of a curve at throat and mouth, like in the picture. The larger and smoother you can make the mouth curve, the better it will be... but too big gets awkward, obviously.
The DIY project I linked in post 9 is, IMO, a good example + fairly easy to replicate (or do a smaller copy).
Klipsch K402 replica build - DIY Audio Projects - StereoNET
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If the horn was long (deep), the issue might have been your 3.5" fullrange -- it's gonna have some pretty nasty off-axis HF radiation by itself and that's going to bounce back and forth down through the horn tube. Might have worked better with a smaller driver, or made as a 90degree waveguide which is nice and short and holds directivity to a lower frequency for a given mouth size.
maLx, reading is good.
What is the purpose? A full conical would be a waveguided system. Should the OP just begin with one horn and see how it goes or make a decision?
I was trying to say don't copy that original link, at least try to understand it first.
What is the purpose? A full conical would be a waveguided system. Should the OP just begin with one horn and see how it goes or make a decision?
Yea, I think that one horn would be a good starting point.
A small fullrange driver on a prebuilt horn (vintage or off-the shelf)
+ loads of eq
+ a separately amplified woofer
I'd be a quick & easy start, and the system could scale up if required.
Some examples here:
Small format cone driver in horn thread
More about conical horns
First, I think that the definitions waveguides and horns is very blurred. Probably most would say that they are largely the same.
My cardboard 60 degree conical horns are intended to reduce dispersion (constrained directivity) to prevent early reflections, thus, they are waveguides. However, because they are conical, they avoid beaming (the pattern control of the highest frequencies is determined early on in the horn) that occurs with exponential horns, thus, with the help of phase plugs, the higher frequencies have a wider dispersion.
But, even with conical horns, the pattern control and the loading of the driver increases the output (the efficiency) at the listening position, thus, they are also a horn.
I could call them either a horn or a waveguide, or use either term, for that matter as both apply.
Second, I don't think that you need any kind of rounding at the throat of the conical horn if you are using a cone speaker. When Geddes was really touting the benefits of OS waveguides, it was really in the context of compression drivers, which come with an exit angle already baked in. Thus, you need to match the starting angle of the waveguide with the exit angle of the compression driver to avoid a sudden discontinuity that would contribute to HOMs. Cone drivers don't have any exit angle. I could see designing the mating of waveguide to the cone driver to avoid discontinuity (for example, in my case, the frame of the driver is exposed at the horn throat - I intend to avoid this when I make a permanent horn). However, a rounding of the horn throat provides such a discontinuity (although it is not too bad because it is rounded). I would think that a constant angle right from the termination at the driver at the horn throat would be the best approach.
Do I have any hard evidence to support my theory about this (and it is only a theory)? No. I do recall that a guy named JohninCR made some waveguides/horns for some cone drivers and tried both a straight angle and an OS waveguide style roundover at the throat. He thought that the straight conical without a throat roundover sounded better.
The data is clear, though, that a roundover at the horn mouth reduces HOMs. I think that a compelling example of that is the guy who spoke through a magazine rolled up as a megaphone, with and without a towel wrapped around the megaphone mouth provided the most compelling evidence of that. Clearly, the megaphone with the towel at the horn mouth sounded clearer.
Retsel
First, I think that the definitions waveguides and horns is very blurred. Probably most would say that they are largely the same.
My cardboard 60 degree conical horns are intended to reduce dispersion (constrained directivity) to prevent early reflections, thus, they are waveguides. However, because they are conical, they avoid beaming (the pattern control of the highest frequencies is determined early on in the horn) that occurs with exponential horns, thus, with the help of phase plugs, the higher frequencies have a wider dispersion.
But, even with conical horns, the pattern control and the loading of the driver increases the output (the efficiency) at the listening position, thus, they are also a horn.
I could call them either a horn or a waveguide, or use either term, for that matter as both apply.
Second, I don't think that you need any kind of rounding at the throat of the conical horn if you are using a cone speaker. When Geddes was really touting the benefits of OS waveguides, it was really in the context of compression drivers, which come with an exit angle already baked in. Thus, you need to match the starting angle of the waveguide with the exit angle of the compression driver to avoid a sudden discontinuity that would contribute to HOMs. Cone drivers don't have any exit angle. I could see designing the mating of waveguide to the cone driver to avoid discontinuity (for example, in my case, the frame of the driver is exposed at the horn throat - I intend to avoid this when I make a permanent horn). However, a rounding of the horn throat provides such a discontinuity (although it is not too bad because it is rounded). I would think that a constant angle right from the termination at the driver at the horn throat would be the best approach.
Do I have any hard evidence to support my theory about this (and it is only a theory)? No. I do recall that a guy named JohninCR made some waveguides/horns for some cone drivers and tried both a straight angle and an OS waveguide style roundover at the throat. He thought that the straight conical without a throat roundover sounded better.
The data is clear, though, that a roundover at the horn mouth reduces HOMs. I think that a compelling example of that is the guy who spoke through a magazine rolled up as a megaphone, with and without a towel wrapped around the megaphone mouth provided the most compelling evidence of that. Clearly, the megaphone with the towel at the horn mouth sounded clearer.
Retsel
Ideally, both driver and horn are considered as one coupling system, from the diaphragm to the horn mouth. This implies a smooth transition along the various components inside the system without major disturbances in the pathway of the wavefront.
The purpose of a roundover, mouth extension or "end- correction" is a smoother transistion from pressurized wavefront inside a horn to the surrounding air in order to minimize interferences.
An important factor to consider is the compression ratio of said system.
The purpose of a roundover, mouth extension or "end- correction" is a smoother transistion from pressurized wavefront inside a horn to the surrounding air in order to minimize interferences.
An important factor to consider is the compression ratio of said system.
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There are pro's and con's to every horn profile, but I will stick to what Dr. Bruce Edgar says
" The tractrix horn profile sounds best in the midrange"
I would look in Dave's Fast Lane Audio's Eliptrac 400hz. horn kit and use a good 2" compression driver. This horn sounds excellent and cost $250 + shipping. This design uses all cnc cut MDF and is easy to assemble if you have a place to work. Good luck.
" The tractrix horn profile sounds best in the midrange"
I would look in Dave's Fast Lane Audio's Eliptrac 400hz. horn kit and use a good 2" compression driver. This horn sounds excellent and cost $250 + shipping. This design uses all cnc cut MDF and is easy to assemble if you have a place to work. Good luck.
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