You might ask yourself : what advantage do you expect, choosing horns, over direct radiators ?
or.....
TPL150/12p80nd
that is 100db.... 2 way
http://www.diyaudio.com/forums/multi-way/231551-beyma-12p80nd-tpl-150-a.html
You are missing my point. The JBL horn will have diffraction to spread the treble. This is how the 2504 spreads the treble. The treble will not beam on the JBL horn.
The answer is, better transient response. Better dynamics. Higher sensitivity.
Diffraction is a problem only when it is a result of poor design such as the edges of a cabinet causing diffraction effects. A diffraction lens that is properly designed is not the same thing as that is an intentional design feature. Given that it is still not necessarily a great idea to mix a horn with one type of polar response with a diffraction lens with a very different polar response.
I have all that with my Beymas - without the shortcomings of horns
Great, go start a thread about it. You are missing the whole point of this thread.
You are mostly right here. Both the horn and the tweeter (2405) use diffraction intentionally for HF dispersion.
So back to your second point, why bother with the superfluous tweeter?
Helmuth,
Please note 2360a are for free, here at home so I am trying to understand pros and cons of this horn now.
Also, I dont doubt you have a wonderful experience with Pro drivers.
In my case I have wonderful experiences with some features of L-100, Avant Gardes, KEF 105, ATC50, Everest D55000. I havent heard it all, so I have to go with my experience first, to show where what I am looking for could be.
So I naturally tend to follow what I've seen works well.
I've never seen those toilet like Seos horn at work... and you are right, they are damn ugly, and I admit that doesnt invite to buy somehting that you never hear before
But I've know I like horns, and I liked the sound of those biradials in the everest project.
So probably also, is my lack of more experience what is involved...
Please note 2360a are for free, here at home so I am trying to understand pros and cons of this horn now.
Also, I dont doubt you have a wonderful experience with Pro drivers.
In my case I have wonderful experiences with some features of L-100, Avant Gardes, KEF 105, ATC50, Everest D55000. I havent heard it all, so I have to go with my experience first, to show where what I am looking for could be.
So I naturally tend to follow what I've seen works well.
I've never seen those toilet like Seos horn at work... and you are right, they are damn ugly, and I admit that doesnt invite to buy somehting that you never hear before
But I've know I like horns, and I liked the sound of those biradials in the everest project.
So probably also, is my lack of more experience what is involved...
Going back to the tweeter/horn discussion...
I like your argument about tweeter alignment.
Also I read a bit what I could find about horns last night, specially Difraction and Biradial horns.
So I am evaluating using the BMS 4590 (instead of 4591 + supertweeter).
So my questions is... what would I expect in terms of Highs beaming?
Is it going to have a narrow sweet spot or not?
I not very familiar with this concept of difration in this design.
Best,
I like your argument about tweeter alignment.
Also I read a bit what I could find about horns last night, specially Difraction and Biradial horns.
So I am evaluating using the BMS 4590 (instead of 4591 + supertweeter).
So my questions is... what would I expect in terms of Highs beaming?
Is it going to have a narrow sweet spot or not?
I not very familiar with this concept of difration in this design.
Best,
I am looking at the 2360a datasheet:
http://www.jblpro.com/pub/obsolete/23606566.pdf
Shows that there is no beaming up to 10khz... that seems very good to me... probably never got something better with my Sabas or Fostexs at home...
in the 10khz-20khz and 20degres it still looks quite decent...
Also wondering if I would be able to hear anything avobe 10khz...
So I am concluding bms4590 and this horn should be good enough for the 300hz-20khz range....
Am I right?
http://www.jblpro.com/pub/obsolete/23606566.pdf
Shows that there is no beaming up to 10khz... that seems very good to me... probably never got something better with my Sabas or Fostexs at home...
in the 10khz-20khz and 20degres it still looks quite decent...
Also wondering if I would be able to hear anything avobe 10khz...
So I am concluding bms4590 and this horn should be good enough for the 300hz-20khz range....
Am I right?
You have answered your own question with the PDF on the next post.
To expand on that, the beamwidth on the 2360 is better than that of the mentioned Beyma tweeter. It is not as smooth a roll off as the 2405, but not that far off from it.
As far as hearing above 10khz, yes you will be able to hear it.
Hi charly
You ask about “sweet spot”, if you mean the width of the seating area that you get a near perfect stereo image that is one thing, if you mean how wide is the area that one speaker sounds the same, that is another. The latter is the degree of constant directivity it has or doesn’t have (changing directivty).
Also “diffraction” is generally a “bad thing” but the reason why is less clear. When you have diffraction, like at the edge of a tweeter or cabinet edge, there is an acoustic discontinuity and so, sound is also radiated from THAT discontinuity. Ideally then, what you do not want is more than one source of sound, two or more sources of sound produce an interference pattern / comb filtering. When we take a response measurement and see a series of dips and peaks, we are often seeing a comb filter as it appears in that measurement point in space. A measurement called a Cepstrum can identify the time periodicity of this issue One way to describe what comb filters is, is the interaction of a direct and reflected (delayed) signal. An ideal horn deals with refraction entirely, it contains the wave propagation until its acoustic dimension is large enough to propagate freely without further angular expansion and at all frequencies radiates as if it were coming from one tiny point.
The horns you linked to are an example of how close one can get in the real world for a one driver horn. There are other ways but those were nice horns.
As for the BMS coax driver, I am familiar with that one and I believe if you had a suitable horn and made your end response flat and happy, you would be ecstatic with the results.
There is a giant advantage to horn directivity if preserving a stereo image is the end goal. For example here they concluded loudspeaker directivty was one of the most important factors in making the cross talk cancelation to work. More information arrives at the listener the more directivity you have (other things being equal).
3D3A Lab at Princeton University
What one cannot have with Constant directivity and a 1.4 or 2 inch exit driver is a wide angle horn.
In practice, at the very top end, even a 1 inch exit can only radiate as a point into a horn about 50 to maybe 70 degrees wide without some interference and no more. Keep in mind, 20KHz is a wavelength of only about 5/8 inch and figure that out front, where ever you can see the driver, you are in the full band width pattern.
How low you can use the driver depends on how much acoustic loading your horn provides at the bottom (which governs the raw response corner) and how loud you wish to listen.
I can tell you that essentially ALL of the bad things loudspeakers do, increase faster than the signal we want to reproduce and so “headroom is always your friend”.
I know of instances where a speaker with three of those drivers provides hifi sound for 30,000+ people at foot ball games etc. In other words, they would be still be effortlessly loafing as loud as your ever likely to listen in your living room. To do it right, you also need to be able to measure the raw responses and deal with them, the easiest way is electronically. Horn systems are harder to make work properly and have more things to deal with, but they deliver more of the signal to the listening position than others too.
Have fun in horn land, it’s a cool place.
Best,
Tom
You ask about “sweet spot”, if you mean the width of the seating area that you get a near perfect stereo image that is one thing, if you mean how wide is the area that one speaker sounds the same, that is another. The latter is the degree of constant directivity it has or doesn’t have (changing directivty).
Also “diffraction” is generally a “bad thing” but the reason why is less clear. When you have diffraction, like at the edge of a tweeter or cabinet edge, there is an acoustic discontinuity and so, sound is also radiated from THAT discontinuity. Ideally then, what you do not want is more than one source of sound, two or more sources of sound produce an interference pattern / comb filtering. When we take a response measurement and see a series of dips and peaks, we are often seeing a comb filter as it appears in that measurement point in space. A measurement called a Cepstrum can identify the time periodicity of this issue One way to describe what comb filters is, is the interaction of a direct and reflected (delayed) signal. An ideal horn deals with refraction entirely, it contains the wave propagation until its acoustic dimension is large enough to propagate freely without further angular expansion and at all frequencies radiates as if it were coming from one tiny point.
The horns you linked to are an example of how close one can get in the real world for a one driver horn. There are other ways but those were nice horns.
As for the BMS coax driver, I am familiar with that one and I believe if you had a suitable horn and made your end response flat and happy, you would be ecstatic with the results.
There is a giant advantage to horn directivity if preserving a stereo image is the end goal. For example here they concluded loudspeaker directivty was one of the most important factors in making the cross talk cancelation to work. More information arrives at the listener the more directivity you have (other things being equal).
3D3A Lab at Princeton University
What one cannot have with Constant directivity and a 1.4 or 2 inch exit driver is a wide angle horn.
In practice, at the very top end, even a 1 inch exit can only radiate as a point into a horn about 50 to maybe 70 degrees wide without some interference and no more. Keep in mind, 20KHz is a wavelength of only about 5/8 inch and figure that out front, where ever you can see the driver, you are in the full band width pattern.
How low you can use the driver depends on how much acoustic loading your horn provides at the bottom (which governs the raw response corner) and how loud you wish to listen.
I can tell you that essentially ALL of the bad things loudspeakers do, increase faster than the signal we want to reproduce and so “headroom is always your friend”.
I know of instances where a speaker with three of those drivers provides hifi sound for 30,000+ people at foot ball games etc. In other words, they would be still be effortlessly loafing as loud as your ever likely to listen in your living room. To do it right, you also need to be able to measure the raw responses and deal with them, the easiest way is electronically. Horn systems are harder to make work properly and have more things to deal with, but they deliver more of the signal to the listening position than others too.
Have fun in horn land, it’s a cool place.
Best,
Tom
It is not increased directivity, it is increased dispersion of the highs that make the filter necessary.
As Tom points out, to get the best results, you must be able to measure your system, and make corrections, and it will be easier to do electronically than passively.
You will need to do more than just correct for the HF rolloff. You will need to have filters to cut out bumps, and make your driver/horn combination as flat as possible in response.
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