Hi, Everyone.
So I've decided to undertake a pretty interesting project. I want to build myself a set of loudspeakers that are smaller versions of what OMA builds Oswalds Mill Audio Imperia is a $280,000 horn speaker | What Hi-Fi?
I'd use 4ohm focal drivers for something similar. The issue I am facing is that I have huge space limitations. So I'm trying to design some small and simple horns for a possible 6" midrange woofer and a 3" midrange woofer (I already have two 10" subs in the room performing great--and the tweeters I'm mounting just in free air)
What I am trying to understand is how do I properly calculate these horn sizes or at least understand what the frequency response of the speaker will be when they are in horns or at least know what I'm getting into.
I've tried Hornresp but I think I'm too much of a noob to understand it all.
Any advise on how to get started designing the horn and then having a possible SketchUp drawing of what the CNC cuts would need to be would be much appreciated.
Thanks,
Joey
So I've decided to undertake a pretty interesting project. I want to build myself a set of loudspeakers that are smaller versions of what OMA builds Oswalds Mill Audio Imperia is a $280,000 horn speaker | What Hi-Fi?
I'd use 4ohm focal drivers for something similar. The issue I am facing is that I have huge space limitations. So I'm trying to design some small and simple horns for a possible 6" midrange woofer and a 3" midrange woofer (I already have two 10" subs in the room performing great--and the tweeters I'm mounting just in free air)
What I am trying to understand is how do I properly calculate these horn sizes or at least understand what the frequency response of the speaker will be when they are in horns or at least know what I'm getting into.
I've tried Hornresp but I think I'm too much of a noob to understand it all.
Any advise on how to get started designing the horn and then having a possible SketchUp drawing of what the CNC cuts would need to be would be much appreciated.
Thanks,
Joey
If you like the look of the OMA, you might also fancy the Jadis Eurythmie. The driver layout / unusual styling are somewhat similar, but it would be much cheaper to clone.
This is an intro to hornresp:
Hornresp for Dum... hmm... Everyone
- Home Theater Forum and Systems - HomeTheaterShack.com
Note that if you shrink the horns, they won't go as low. If your horns only reach down to 400Hz (for example), you'll need to add a woofer to fill the gap between the subs and the horns.
What is your space? Do you own it?
This is an intro to hornresp:
Hornresp for Dum... hmm... Everyone
- Home Theater Forum and Systems - HomeTheaterShack.comNote that if you shrink the horns, they won't go as low. If your horns only reach down to 400Hz (for example), you'll need to add a woofer to fill the gap between the subs and the horns.
What is your space? Do you own it?
Thanks for the info! It’s going in my condo and yes I own it. When you ask what my space is do you want measurements and layout? I can draw those up and provide them. I’m trying to marry a home theater setup with two loudspeakers, where as when I listen to music the receiver will go into two channels mode. I was thinking of using a Pioneer Elite LSX-102 as it goes 4ohm at 170w a channel. I have a Pro-Ject XB Experience Turntable with a Pro-Ject tube box phono amp, a Kimber cable, and a Blue Point Cartridge.
Also I have two Pioneer Shallow 10” subs which I am happy with their output level, but I think I want to build them a stronger, slightly bigger sealed box. This will all be staying and what will be leaving is my 5 B&W m1 speakers for something I make.
Also I have two Pioneer Shallow 10” subs which I am happy with their output level, but I think I want to build them a stronger, slightly bigger sealed box. This will all be staying and what will be leaving is my 5 B&W m1 speakers for something I make.
This page and calculator have good info on cutting conical horns in that style:
100 Hz Multi-sided Conical Midbass Horns - DIY Firefly
Compound Miter Saw Calculator
If you don't have the requisite tools / want to skip some of the labour, IKEA have wooden bowls (Sekin) that can be turned into horns, like this:
Horn FAST in timber
Your 6" midwoofer could be good for 350Hz - ?4kHz.
The LF limit will depend largely on the baffle / mouth termination, the HF will depend on the driver.
100 Hz Multi-sided Conical Midbass Horns - DIY Firefly
Compound Miter Saw Calculator
If you don't have the requisite tools / want to skip some of the labour, IKEA have wooden bowls (Sekin) that can be turned into horns, like this:
Horn FAST in timber
Your 6" midwoofer could be good for 350Hz - ?4kHz.
The LF limit will depend largely on the baffle / mouth termination, the HF will depend on the driver.
Since you own it, would it be a possibility to suspend your horns from the roof? That'd allow you to go big without taking up any floor space.
With rough dimensions + a photo people will be able to help more. I'm just a tinkerer. There will be others who know more about room effects / integration that will have good tips.
Another lazy tip: If you want the look of wood, without the work, you can just add a wood veneer to an existing horn, as on this page:
No Audiophile Field Trip #1
Super bold idea! The one reason why I don’t want to do that is because of the layout. If I suspend them from the ceiling, I’d have to angle them in a way where I’d have one very specific focal point and if they were on the floor and about 5 feet tall... I’d have a good focal point but it would also extend backward a bit so if I’m entertaining people in the kitchen they will still be able to have a good listening experience. If I draw up the room layout with some photos would that help or can you get what I’m saying from my explanation?
The floor space isn’t the problem I don’t think also. I have a large wall unit that extends up to the ceiling of that same room so if I have 4 cubic of floor space I’ll have the same on the ceiling and the horns would be almost facing down.
The floor space isn’t the problem I don’t think also. I have a large wall unit that extends up to the ceiling of that same room so if I have 4 cubic of floor space I’ll have the same on the ceiling and the horns would be almost facing down.
There is a great thread on an almost full conical system from a couple of years ago that follows the practical development of a system like this, but the search system prevents me from using words like 'seven' and 'big' in a title search. I can't find it. Anyway..
Conical horns (or equivalent) can be an excellent choice, especially at higher frequencies. OMA say..
Conicals have a complex set of trade-offs. One means that they can be more difficult to terminate, and to make small. The lower horns in your link appear to be compromised acoustically toward making them less easy to call conical.
Although fundamentally this design looks reasonable within limits, for the price it is shamefully lacking.
Conical horns (or equivalent) can be an excellent choice, especially at higher frequencies. OMA say..
This is one of their benefits, but it isn't the end of the story.OMA said:
Conicals have a complex set of trade-offs. One means that they can be more difficult to terminate, and to make small. The lower horns in your link appear to be compromised acoustically toward making them less easy to call conical.
Although fundamentally this design looks reasonable within limits, for the price it is shamefully lacking.
Is this the one you mean?
A K-402-Based Full-Range Multiple-Entry Horn - Technical/Modifications - The Klipsch Audio Community
Conical horns don't have a focal point that sounds best. Actually, right on axis is where they measure worst.
Anywhere in the covered angle sounds about the same. That's the strength of conical (and other constant directivity) horns.
Here is an example of a (mostly) conical horn with wide dispersion. A nice DIY effort, well described:
Klipsch K402 replica build - DIY Audio Projects - StereoNET
I'd think that something more or less like that could work well mounted against the ceiling - it would have wide enough coverage to suit multiple listening spots.
No, this one was a floor to ceiling stack of conical separates. IIRC it had a few gems of wisdom such as some lower frequency size and profile compromises and their trade-offs.
I had a big conical horn(60/90/70 cm, H/W/D), synergy loaded with a 3.5" full range and 12" midbass. The measurement looked ok but in the end I scraped it. There was something in the sound that made long time listening tiring. Maybe there were HOMs.. i don't know.
I did also a tractrix horn with a 4" full range, covering 300-3k, it was much better regarding listening time, could listen all day long. Could be that it was not so deep and tractrix, so less HOMs? I don't know..(36/50/40 cm, H/W/D)
You can check also other profiles, Le Cleach for example, it is said to be good.
I did also a tractrix horn with a 4" full range, covering 300-3k, it was much better regarding listening time, could listen all day long. Could be that it was not so deep and tractrix, so less HOMs? I don't know..(36/50/40 cm, H/W/D)
You can check also other profiles, Le Cleach for example, it is said to be good.
Hi, All.
So here are the woofers/Tweeters I am using for the Loudspeakers. The 3" woofer is what I am thinking of putting a horn next to with the goal of having good sound projection and depth and no distortion.
You can find the spec sheets for all in the folder here: Drivers - Google Drive
Additionally, I'm looking at the link that Hollowboy provided. I just want to ensure that I am understanding this correctly: https://www.screencast.com/t/LvoOZfwi
So this would be a horn with 12 sides, that is 14cm near the speaker and if I were to measure it front to back it would be 33cm? But how do I know how big the mouth is?
I know these are noob questions but you guys have been amazing with help! Excited to get this project done.
So here are the woofers/Tweeters I am using for the Loudspeakers. The 3" woofer is what I am thinking of putting a horn next to with the goal of having good sound projection and depth and no distortion.
You can find the spec sheets for all in the folder here: Drivers - Google Drive
Additionally, I'm looking at the link that Hollowboy provided. I just want to ensure that I am understanding this correctly: https://www.screencast.com/t/LvoOZfwi
So this would be a horn with 12 sides, that is 14cm near the speaker and if I were to measure it front to back it would be 33cm? But how do I know how big the mouth is?
I know these are noob questions but you guys have been amazing with help! Excited to get this project done.
The use of conical horns for midrange and treble is an exceptionally bad idea. Spend a few minutes with axidriver or hornresp and you'll see what I mean.
An oblate spheroidal waveguide is largely a conical horn with a spline at the throat and a roundover at the mouth.
So, you might wonder, "How can an oblate spheroidal waveguide sound good when a conical horn sounds bad?"
I think the answer to that question is twofold:
1) The spline at the throat and the roundover at the mouth is REALLY important. 'The devil is in the details' and though a conical horn and OS waveguide look similar, those two additions make a world of difference. In particular, if you spend some time simulating waveguides, you'll find that once a wavefront is screwed up, there's no way to repair it. IE, if the throat of your waveguide or horn isn't perfect, you might as well throw the horn in the trash.
2) OS waveguides are very large, considering how narrow the bandwidth is. For instance, the OS waveguide in the Gedlee Summa loads the compression driver down to approximately 450Hz. Basically the waveguide is exceptionally large for a tweeter, and by using such a large waveguide, you avoid the pitfalls of a small waveguide. Mouth diffraction in particular.
Long story short: I honestly can't think of any good reason to use a conical horn, except for a basshorn. For midrange and treble? There are dozens of superior options.
Side note: about five years ago, a French audiophile group measured the Oswald Mills horns, IIRC. The results of that test may be, um, "enlightening."
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Assuming you'll run:
Faital HF
3" midrange (on horn)
6.5" bass (direct radiating)
+ subwoofers
a) that's a pretty complex build
b) your system efficiency will be limited by the 6'5" to about 85dB. The Faital bullet tweeter will be about 20dB more sensitive than the rest of the system
c) the 3" and the Faital are a poor match. The Faital is recommended for crossover >2.6kHz. The 3" has a big peak and dip at 2-3kHz, implying it works best with a crossover below 2kHz
...so I'd consider simplifying. Get a small driver with a wider response, e.g:
Test Bench - SB Acoustics SB65WBAC25-4 2.5” full-range driver
Put that on a horn, and don't use a tweeter at all.
"The base radius is the distance from the center of the pyramid's base to one of the base corners."
Another way to do this is with hornresp. It calculates petal sizes (but not cut angles), discussed here:
Hornresp
And yet another way to build them:
doityourselfaudio: 140Hz Petal Horns
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Citing a difference between OS and conical could be splitting hairs. If the driver produced the right spherical wavefront then the cone would be appropriate, in fact, that might be ideal. They don't though, because this would dictate the necessary horn and remove versatility from the driver so they settle on a plane wavefront. This is the reason OS is used as much as it is but its qualities are conceptually as conical.
With regard to bass conicals, in the original link the angle of the profiles narrows as frequencies get lower. This makes them appear to be truncated exponentials, or at best, a mixture. Loading has been considered, where normally directivity would not necessarily want to narrow with decreasing frequency. Not that it necessarily would with these lower horns. It just seems that they are classified as conical for marketing purposes.
With regard to bass conicals, in the original link the angle of the profiles narrows as frequencies get lower. This makes them appear to be truncated exponentials, or at best, a mixture. Loading has been considered, where normally directivity would not necessarily want to narrow with decreasing frequency. Not that it necessarily would with these lower horns. It just seems that they are classified as conical for marketing purposes.
Do an HR model of an unterminated conical horn and then look at the impulse spectrogram that HR can produce. You'll see multiple levels of mouth reflections. A conical horn with a secondary flare isn't much better. Patrick is correct; a conical horn really needs roundovers at the mouth and a spline at the throat to match CD exit angle doesn't hurt either.
My Conical Horn experiment
I made 60 degree square conical horns for my Lowther DX4 Drivers by attaching the horn onto the open baffles that they were mounted to (Basszilla). I used some large pieces of cardboard and the horns measure 3 feet long and almost 4 feet per side at the mouth. To keep the design simple, the throat of the horn is 8 inches square, attaching to the open baffle just to the outside of the Lowther driver. They are a little leaky at the point of attachment (keep in mind that this is simply an experiment), but I don't think that this is a big deal. I simply damp the rear wave with some thick insulation.
I needed to come up with a new crossover for the DX4s. While the horn brings up the lower frequencies nicely, the Lowthers still have a large hump in the 5k to 10K region, and it took some experimentation to shelve that down to be flat. Prior to fixing that, a lot of music was unlistenable as the high frequencies were just too strong.
I had to get creative with a supertweeter. What I did was to cut a small slit in the top of the horn near the throat just large enough to allow the Gs2i supertweeters to face down into the horn. It is a bastardized arrangement, but it does bring in some high frequencies.
I have a pair of 15 inch drivers on open baffle to cover 150 hz up to 500 hz, and a pair of long throw 18 inch drivers also on a quasi open baffle for under 150 hz.
Several observations:
The conical horns only load the DX4 drivers down to 500 hz. This is where a tractrix (including the laCleach) excels because the narrower throat loads the bass frequencies better.
Dispersion is wide, likely much better than a tractrix which would beam the higher frequencies - this is important because I plan on using this for a home theater.
Avoiding of the reflections off the side walls really cleans up the soundstage. Also, horns can be pushed all the way back against the back wall, so they are not at imposing as one might think.
There likely are HOMs, likely created because of the sudden termination of the horn into free air at the mouth.
My plans going forward is to make the throat much smaller, to be about equal to SD of the driver - this will likely lower the horn cutoff some. I will likely make the horn walls out of reinforced MDF, which is better damped than plywood.
I also plan on adding a large (6 - 12 inches) of a "roundover" with fabric filled with soft Styrofoam or open cell foam at the mouth termination to dampen the reflections at the mouth.
Near term, I intend to run the supertweeter off the 4 ohm taps of my SET output transformers which will raise the output relative to my DX4s, which are run off of the 8 ohm tap. Long term, I will come up another way to inject 7K+ hz into the horn - maybe a Transylvania tube???
Overall, I am encouraged by the experiment, at least enough to keep going. I like the wide dispersion of the Conicals. These speakers are in a fairly large room (19 feet by 26 feet with a vaulted ceiling) and the horns really help to fill this room with sound whereas the open baffles sometimes would not (using a SET amp) depending on the loudness of the source.
Retsel
I made 60 degree square conical horns for my Lowther DX4 Drivers by attaching the horn onto the open baffles that they were mounted to (Basszilla). I used some large pieces of cardboard and the horns measure 3 feet long and almost 4 feet per side at the mouth. To keep the design simple, the throat of the horn is 8 inches square, attaching to the open baffle just to the outside of the Lowther driver. They are a little leaky at the point of attachment (keep in mind that this is simply an experiment), but I don't think that this is a big deal. I simply damp the rear wave with some thick insulation.
I needed to come up with a new crossover for the DX4s. While the horn brings up the lower frequencies nicely, the Lowthers still have a large hump in the 5k to 10K region, and it took some experimentation to shelve that down to be flat. Prior to fixing that, a lot of music was unlistenable as the high frequencies were just too strong.
I had to get creative with a supertweeter. What I did was to cut a small slit in the top of the horn near the throat just large enough to allow the Gs2i supertweeters to face down into the horn. It is a bastardized arrangement, but it does bring in some high frequencies.
I have a pair of 15 inch drivers on open baffle to cover 150 hz up to 500 hz, and a pair of long throw 18 inch drivers also on a quasi open baffle for under 150 hz.
Several observations:
The conical horns only load the DX4 drivers down to 500 hz. This is where a tractrix (including the laCleach) excels because the narrower throat loads the bass frequencies better.
Dispersion is wide, likely much better than a tractrix which would beam the higher frequencies - this is important because I plan on using this for a home theater.
Avoiding of the reflections off the side walls really cleans up the soundstage. Also, horns can be pushed all the way back against the back wall, so they are not at imposing as one might think.
There likely are HOMs, likely created because of the sudden termination of the horn into free air at the mouth.
My plans going forward is to make the throat much smaller, to be about equal to SD of the driver - this will likely lower the horn cutoff some. I will likely make the horn walls out of reinforced MDF, which is better damped than plywood.
I also plan on adding a large (6 - 12 inches) of a "roundover" with fabric filled with soft Styrofoam or open cell foam at the mouth termination to dampen the reflections at the mouth.
Near term, I intend to run the supertweeter off the 4 ohm taps of my SET output transformers which will raise the output relative to my DX4s, which are run off of the 8 ohm tap. Long term, I will come up another way to inject 7K+ hz into the horn - maybe a Transylvania tube???
Overall, I am encouraged by the experiment, at least enough to keep going. I like the wide dispersion of the Conicals. These speakers are in a fairly large room (19 feet by 26 feet with a vaulted ceiling) and the horns really help to fill this room with sound whereas the open baffles sometimes would not (using a SET amp) depending on the loudness of the source.
Retsel
Were you replying to me? I mentioned terminations in my first post of the thread.
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