So if horn A has a mouth that is 1 meter wide and has horizontal coverage of 40 degrees...
And if horn B mouth is 25 cm wide and has 80 degrees of horizontal coverage...
Which horn has wider coverage in reality at the listening spot?
Is the dispersion pattern measured from the driver or from the horn mouth?
Do smaller horns have more narrow dispersion in reality because of the smaller mouth size?
And if horn B mouth is 25 cm wide and has 80 degrees of horizontal coverage...
Which horn has wider coverage in reality at the listening spot?
Is the dispersion pattern measured from the driver or from the horn mouth?
Do smaller horns have more narrow dispersion in reality because of the smaller mouth size?
Here tale a look at this for same mouth size vs short, medium and Long throw. You just can't look at just the horn. You need to look at the whole system directivity. Smaller mouth/throat size typically wider dispersion last octave. Frequency wavelength flare rate horn length all matter. Look at the differences between the 3 horns in the attachment.
Rob 🙂
https://www.lansingheritage.org/html/jbl/specs/pro-comp/2360-series.htm
Rob 🙂
https://www.lansingheritage.org/html/jbl/specs/pro-comp/2360-series.htm
Hi,
simplest way to summarize is that mouth size relates to how low in frequency a horn can control sound. This is true for any objects, not just horns, but regular flat speaker box baffles as well!
The relationship is quite simply between physical size of the object and sound wavelength. Small objects can control only high frequencies, whose wavelength is short. Conversely the object needs to be big the lower in frequency you wish to control the sound. 1kHz is 34cm long so you need object roughly that size to have some control. Too small object has about no effect, the sound just diffracts around it as if it didn't exist when wavelength is about 10x size of the object. If you had the 34cm sized horn and scaled that to 3.4m it would have same pattern control down to 100Hz. You'd need 34m sized device to have it down to 10Hz, or 3.4cm device if you only need to control 10kHz.
Nominal coverage, like 40deg or 80deg you mentioned, happen only on shorter wavelengths than size of the object. A 40deg nominal coverage device would have to be very deep, in order to have most part of the "walls" in 40deg angle from throat to mouth. You could use simple trigonometry to get rough figure for horn depth. Using 1m mouth diameter and 40deg nominal coverage, the depth would need to be about 1.4m. Same calculation for 80deg nominal device gives about 60cm for depth. You could have it deeper or shallower, and it would affect the actual device profile and coverage pattern that results, so it's not as simple as this 🙂
You can get into details by searching around, reading books about it.
simplest way to summarize is that mouth size relates to how low in frequency a horn can control sound. This is true for any objects, not just horns, but regular flat speaker box baffles as well!
The relationship is quite simply between physical size of the object and sound wavelength. Small objects can control only high frequencies, whose wavelength is short. Conversely the object needs to be big the lower in frequency you wish to control the sound. 1kHz is 34cm long so you need object roughly that size to have some control. Too small object has about no effect, the sound just diffracts around it as if it didn't exist when wavelength is about 10x size of the object. If you had the 34cm sized horn and scaled that to 3.4m it would have same pattern control down to 100Hz. You'd need 34m sized device to have it down to 10Hz, or 3.4cm device if you only need to control 10kHz.
Nominal coverage, like 40deg or 80deg you mentioned, happen only on shorter wavelengths than size of the object. A 40deg nominal coverage device would have to be very deep, in order to have most part of the "walls" in 40deg angle from throat to mouth. You could use simple trigonometry to get rough figure for horn depth. Using 1m mouth diameter and 40deg nominal coverage, the depth would need to be about 1.4m. Same calculation for 80deg nominal device gives about 60cm for depth. You could have it deeper or shallower, and it would affect the actual device profile and coverage pattern that results, so it's not as simple as this 🙂
You can get into details by searching around, reading books about it.
Last edited:
Horn B has more 'dispersion' while horn A is said to have more directivity.
Dispersion is measured in the house and there're two methods:
- Rotate the loudspeaker and keep the microphone(s) stationary and somewhere sensible.
- Keep the loudspeaker stationary and move the microphone(s) around the house.
As mentioned by Robh3606, horn length, flare rate, coverage angle and driver diameter all matter. It is possible for two horns, one large and one small, to have the similar coverage angle, flare rate and dispersion characteristics, but across different frequency bands. I hope that gives some idea.
Yes i understand the basics
Mouth size, horn size is depending on a frequency
I was thinkering bwaslo sym calc v5 and that got me thnking... the lower with frequency you go, the horn size gets big and fast
Why i ask is, because most narrow dispersion MEH possible to be used with ubacch system...
Meaning i need electrostatic level narrow dispersion
Ubacch works well only with the most narrow dispersion speakers and once you hear the system working, theres no turning back... every another "one million dollar" system is just so boring when the stereo image is between the speakers, and not at your ear
Maybe its another topic
But yes i need the most narrow dispersion possible horn with directivity, hopefully constant, starting from 300hz, no matter of what size horn
I looked into paraline, its narrow dispersion, but didnt find any working diy projects
Mouth size, horn size is depending on a frequency
I was thinkering bwaslo sym calc v5 and that got me thnking... the lower with frequency you go, the horn size gets big and fast
Why i ask is, because most narrow dispersion MEH possible to be used with ubacch system...
Meaning i need electrostatic level narrow dispersion
Ubacch works well only with the most narrow dispersion speakers and once you hear the system working, theres no turning back... every another "one million dollar" system is just so boring when the stereo image is between the speakers, and not at your ear
Maybe its another topic
But yes i need the most narrow dispersion possible horn with directivity, hopefully constant, starting from 300hz, no matter of what size horn
I looked into paraline, its narrow dispersion, but didnt find any working diy projects
Last edited:
Narrow means bigger mouth and longer horn. This post shows using one narrow dimension but the same can be said about narrow waveguides in general.
https://www.diyaudio.com/community/...on-axisymmetric-waveguide.375799/post-6754096
https://www.diyaudio.com/community/...on-axisymmetric-waveguide.375799/post-6754096
This is a complicated question.
Although some generalizations can be made, the only way to visualize dispersion is to imagine the horn shape as a barrier in a body of water, with ripples coming out of it. The curvature and dimensions affect how the waves travel and disperse. There's no real easy math here, it requires computer simulation to model it accurately. Slight changes can make huge differences in frequency response at various angles, and the differences at one frequency are not the same at others.
The best way to understand what a horn will do is to look up the specifications and graphs given by the manufacturer, and do your best to read and interpret them.
This subject is complicated enough to fill an entire semester in grad school. A course on microwave/radio antenna and wave guides with the associated mathematics - calculus and computer simulation - would have a lot of conceptual overlap although one is to do with electromagnetic waves, and the other sound.
Although some generalizations can be made, the only way to visualize dispersion is to imagine the horn shape as a barrier in a body of water, with ripples coming out of it. The curvature and dimensions affect how the waves travel and disperse. There's no real easy math here, it requires computer simulation to model it accurately. Slight changes can make huge differences in frequency response at various angles, and the differences at one frequency are not the same at others.
The best way to understand what a horn will do is to look up the specifications and graphs given by the manufacturer, and do your best to read and interpret them.
This subject is complicated enough to fill an entire semester in grad school. A course on microwave/radio antenna and wave guides with the associated mathematics - calculus and computer simulation - would have a lot of conceptual overlap although one is to do with electromagnetic waves, and the other sound.
I built a Paraline system, but wouldn't advise it for what you are trying to achieve, a constant directivity narrow pattern horn for home use.
MEH (multiple entry horns) along the lines of the DSL SH25 (25x 25 degree) or the 40 x 30 EV MTS-4153-43FWB would give you very defined narrow coverage angles.
Both are "simple" 2 part "Keele break" conical horns as in the bwaslo .
The SH 25 dimensions are 28" x 28" x 50.7" deep, still far too small to maintain a -6dB coverage angle to 300 Hz.
The bi-radial 40x20 JBL 2366 40x20 horn is similar in size to the SH -25, it looses vertical pattern control below ~900 Hz:
The larger 43" x 43" x 58.7" (1092mm x 1092mm x1491mm) 40x30 EV MTS-4153-43FWB is still too small to control pattern below ~400Hz, it expands to ~100 degrees at 300Hz:
Anyway, that gives you an idea of horn size required for narrow pattern control to low frequencies.
Art
Last edited:
The coverage angle of a horn is measured soon after the driver exit.
When the pattern is narrower, the horn might sound louder as all energy is focussed to a smaller angle. However, slight changes to the listening position could bring about perceivable differences in sound.
Last edited:
That EV mts is really interesting...
How can they sell it with the Danley having the patents?
First i need to finish k-402 meh to see if Ubacch works with it.
How can they sell it with the Danley having the patents?
First i need to finish k-402 meh to see if Ubacch works with it.
Last edited:
The datasheets of the EV speakers mentioned here are interesting. It looks like the coverage pattern for the narrower horn gets as low or even lower than the wider coverage version. The mouth dimensions are the same. What am I missing? Looking at the Bacch site, a reasonably large horn that would fit the room geometry should work well according to what they claim.
Depth of the narrower device is greater than size of mouth, which must relate to it somehow. As in Keele's classic
edit. article here https://audioxpress.com/article/Understanding-Horn-Directivity-Control
The formula and article says that the narrower pattern device would have to have bigger mouth to have control at same low frequency, which is opposite of what EV datasheets show. I think the data in datasheets must be wrong then, or it somehow deviates from this Keele's classic.
edit. article here https://audioxpress.com/article/Understanding-Horn-Directivity-Control
The formula and article says that the narrower pattern device would have to have bigger mouth to have control at same low frequency, which is opposite of what EV datasheets show. I think the data in datasheets must be wrong then, or it somehow deviates from this Keele's classic.
Last edited:
It depends also which system you buy from Ubacch, full headtracking etc or just a plugin
Many people get disappointed with the system when they try it with average 1980's designs "drivers-on-piece-of-wood" speakers, even with tweeter waveguides.
Nothing happens then, plugin on or off
Once speakers have narrow directivity its absolutely amazing, even with plugin only
Many people get disappointed with the system when they try it with average 1980's designs "drivers-on-piece-of-wood" speakers, even with tweeter waveguides.
Nothing happens then, plugin on or off
Once speakers have narrow directivity its absolutely amazing, even with plugin only
Last edited:
They must listen too far then, so that early reflections dominate perception. EQ doesn't affect system directivity, which makes the early reflections. If you have narrower coverage system, you can be listening further out in the room before early reflections start to dominate, so there is higher chance you happen to sit close enough so that early reflections do not dominate perception. So, to fix this for traditional speaker, for any speaker and room, just shrink listening triangle size enough, and in general make good positioning. This is not popular option, as positioning has nothing to sell and nothing to buy, no silver bullets, but requires listening skill and work.
Small listening triangle is not always practical, like in a normal livingroom, in which case one perhaps should acquire narrow coverage system, or do some acoustic treatment, to reduce early reflections, to allow auditory system to pick out the direct sound from noise in the room (early reflections) all the way at the sofa.
Small listening triangle is not always practical, like in a normal livingroom, in which case one perhaps should acquire narrow coverage system, or do some acoustic treatment, to reduce early reflections, to allow auditory system to pick out the direct sound from noise in the room (early reflections) all the way at the sofa.
Last edited:
Many MEH patents have been issued to various individual and corporate entities long before and after those issued to Danley.
Ubacch "works" with any dispersion pattern, it just has less "work" required to remove the room response from the HRTF (head related transfer function) the more narrow (and consistent) the dispersion pattern of the speaker system is.
The Klipsch K-402 has wider horizontal dispersion and is physically wider than the EV MTS horns, so it maintains it's horizontal pattern of ~90 degrees to a lower frequency, ~270 degrees.
The K-402's vertical pattern of ~60 degrees doubles to ~120 degrees ~350Hz ("pattern flip") due to it's more narrow vertical dimensions.
My experience listening to the recorded and live output of binaural head microphones through headphones and very narrow dispersion horns (13x13 WS Maltese, 35x35 EAW KF750 nested horns) make me think the HRTF is more likely to be retrieved from the frequency ranges with wavelengths shorter than the over the head distance from ear drum to ear drum, roughly 700 Hz and higher for my noggin.
In other words, something like the more narrow SH-25 may work better with Ubacch than the K-402, even though it's pattern control does not reach as low.
That said, the K-402 pattern control is far more narrow than any typical front-loaded speaker.
The shorter EV MTS 60x40 and the longer 40x30 horn both have ~100 degree dispersion at 315Hz, a larger relative change in dispersion for the narrower 40x30.
Art
Last edited:
I see, thanks. This makes me want to try a MEH with a narrower angle than usual for the next build.
Informative video about the EV mts system, its optional to have cardioid bass on the system. That way pattern control extends even lower
I quess i can try flipping the k402 sideways if needed, if Ubacch doesnt work well. Meaning having the 60 degrees horizontal 90 degrees vertical. I quess i will get more reflections from floor and ceiling then
Last edited:
I've no experience with Baach, so no idea how to weigh in on the desirability of a narrower patterning using it.
So i just trust you know that you're doing there...
If you're after constant directivity, ala a MEH and using Syncalc, you've no doubt seen how large and how deep a horn gets trying to maintain narrow pattern control lower in freq.
A 40x40 built to 300Hz, is roughly a 5ft wide x 5ft high x 5 ft deep.
30x30 to 300Hz ? ...6ft x6ft x 8 1/2 ft... yikes!
(and those depths don't include the CD depth!)
Personally, I found a 60x60 MEH, good to about 250Hz, to be the largest box I could stomach and move around.
And listening wise, 60x60 to be too narrow. (without Baach of course)
90x60 to about 200Hz, is where I've settled in, after a lot of larger sized MEH experimentations.