Horn Speakers - Is it me or.......

[Tim Link]

A.classic collapsing polar. In those cases, there are other designs that are clearly better than horn IMO.

Like what?

 

[Vineeth Kumar V]

Thanks to people like Marcel (and others) who have given away horn/waveguide design software (ATH) for free, one can do good DIY system designs (with good horns/waveguides) easily, at home these days.
Here is a simple example of what one can cook up at home on a small PC at home in a few hours.

Device width x height = 346.46 x 287.46 mm (13.640 x 11.317")
Device length = 115.00 mm (4.528")
40mm roundovers on all sides 25cm depth to the box..

A prototype MEH version of the above horn (I know the measurement mic mounting is not optimal )

horizontal polar measurements from prototype and sample crossover

Match between BEM simulations and measurements
Dotted line below is the SP DI from SIM
solid line is from actual measurements..

Concept full system design (using dual 15inch drivers for taking care of lower frequencies in Genelec W371 style controlled directivity bass module)

Sample predicted polars of the full system with the above MEH horn

Woofer module cabinet in real

Well in the real world I changed the color of the woofer module cabinets to white..

 

[Vineeth Kumar V]

Here is another example DIY horn system.. The "Hells Bells"

 

[AudioJester]

Thanks to people like Marcel (and others) who have given away horn/waveguide design software (ATH) for free, one can do good DIY system designs (with good horns/waveguides) easily, at home these days.
Here is a simple example of what one can cook up at home on a small PC at home in a few hours.

Device width x height = 346.46 x 287.46 mm (13.640 x 11.317")
Device length = 115.00 mm (4.528")
40mm roundovers on all sides 25cm depth to the box..

A prototype MEH version of the above horn (I know the measurement mic mounting is not optimal )
View attachment 400032
View attachment 400031

horizontal polar measurements from prototype and sample crossover
View attachment 400033

Match between BEM simulations and measurements
Dotted line below is the SP DI from SIM
solid line is from actual measurements..

Concept full system design (using dual 15inch drivers for taking care of lower frequencies in Genelec W371 style controlled directivity bass module)
View attachment 400043
View attachment 400044

Sample predicted polars of the full system with the above MEH horn
View attachment 400045

Woofer module cabinet in real
View attachment 400048

Well in the real world I changed the color of the woofer module cabinets to white..
View attachment 400049
View attachment 400046
View attachment 400047

Incredible!
Iam guessing low distortion at high spl?

 

[Vineeth Kumar V]

Incredible!

Thankyou

Iam guessing low distortion at high spl?

A modular, configurable directivity system was the goal..

 

[Newman]

A prototype MEH version of the above horn (I know the measurement mic mounting is not optimal )

Hi there, what are the drive units on this baby?

 

[Vineeth Kumar V]

Hi there, what are the drive units on this baby?

That is a B&C DE 360 compression driver + B&C 4NDF3416 (4 nos)

 

[Flaesh]

what

BC 4NDF34 mids and DE***-8 driver))

https://www.hifivision.com/threads/a-multi-way-speaker-design-around-the-exar-400-horn.95750/page-3 btw

 

[Vineeth Kumar V]

Most of the stories around the above builds are available here: https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7746756

 

[Tim Link]

Or you haven't heard a quality horn yet... I lean towards that, and especially since you are talking about coloration. That's indication of a horn that's poorly designed.

A lesson I keep learning about high frequency horns is that I don't like them too phyiscally near to anything else. My high frequency horns always sounded a bit odd when I had them sitting flush with the mouth of my bass horn. Moving them forward just a few inches really cleared things up. More recently I've placed them a full foot forward on their own speaker stands, and that brought things to a new level. Now tonight I moved them another 10" forward, and it's just amazing how open and clear they've become. I would not call this colored at all. Very detailed and lush, captivating and beautiful. Strangely, the bass seems clearer and tighter too. I gues the overtones are just clearer integrating better. What I've got is nothing super fancy, just a BL-409 horn bought off of Parts Express for dirt cheap, and hooked up to some JBL 2426h drivers, and then EQ'd using DSP, crossed over at 900 Hz. Maybe not perfect but at this point I'm really having a hard time complaining about the high frequency response. I've heard the JBL HDI series and some of their bigger ones like the 4367. Those sound slightly like horns typically sound to me, especially the 4367. Now I'm wondering if it's just the fact that the horn is right next to and flush with the woofer.

Edit: I listened more to this, and kept moving the tweeters further forward. At some point I become proximity aware of them. The sound also gets "aggressive." What does that mean? It just means I don't think it's good if they get too close. Going back to the first position I liked, I found the effect did not always please me as much, depending on what I was listening to. It makes the highs more direct, which can make them seem too much on some material. I didn't have much luck trying getting a pleasing result turning them down more or adding more delay. I guess I want to hear more reflections on some content. Coloration from reflections can be nice sometimes, adding a perceived richness at the expense of clarity. When people say "microdynamics," I think it's just clarity across a broad frequency spectrum, mixed with good tonal balance. I'm saying that because microdynamics is a word that pops in to my head when trying to describe how it sounds to move the tweeters a little further from other objects. But when I think about what that word means to me, it's the same as clarity. Transients sort of pop out with distinction when there's better clarity, even if the volume change isn't a lot.

 

[Tim Link]

Is there really no penalty to having extra holes along the sides of the horn flare?

 

[Vineeth Kumar V]

Is there really no penalty to having extra holes along the sides of the horn flare?

At least on this particular horn, there are some side effects..
In the above measurements, I used only the drivers at the top and bottom and not the ones on the sides. I had closed the mid taps on the side walls using cellophane tape.. Here are more details about the impact of taps (top/sides) on the CD response

Below is an on axis response plot of the DE 360 on the waveguide in 3 cases
1) All mid ports open (red, lot of wiggles)
2) Side mid ports closed (green, much less wiggles)
3) All mid ports closed (blue, slightly better than above but not by much)

This is the reason why I have changed the location of mid taps on the latest iteration of this MEH as shown below

 

[Head_Unit]

uneven directivity over frequency and narrowing at high frequencies to a pencil beam width.

But they are all highly directional

Well these horns beamed the high frequencies like a laser.

Tweeters do the same thing, all high frequency devices' power response falls off at high frequencies.
- However maybe we are more used to how that is for typical dome tweeters. And depending on the horn design, a tweeter may well be less extreme.
- Lots of horns are really designed for PA use, to beam the sound concentratedly at an audience.
- I believe lots of horns are designed by people who don't really know what they hell they are doing and copycat something else, which in turn is maybe not so informed or outright based on ancient designs.

To achieve flat on-axis response, horns' directivity thus narrows and narrows. The way to do things is really to have a constant directivity, which means a falling response at high frequencies. But in an active system, this can be crossovered/EQ'd out. In a passive system the horn (or waveguided tweeter) would generally be much more sensitive in the midrange than the woofer, and a high crossover frequency should flatten the overall response but with more constant directivity. That's what we are at long hallelujah last starting to see from some makers. Even finally in the budget realm (Monolith) where you can get so much benefit by deepening the plastic ring around a tweeter into a waveguide for minimal additional cost.

 

[Tim Link]

At least on this particular horn, there are some side effects..
In the above measurements, I used only the drivers at the top and bottom and not the ones on the sides. I had closed the mid taps on the side walls using cellophane tape.. Here are more details about the impact of taps (top/sides) on the CD response

Below is an on axis response plot of the DE 360 on the waveguide in 3 cases
1) All mid ports open (red, lot of wiggles)
2) Side mid ports closed (green, much less wiggles)
3) All mid ports closed (blue, slightly better than above but not by much)
View attachment 400960

This is the reason why I have changed the location of mid taps on the latest iteration of this MEH as shown below
View attachment 400961
View attachment 400962

The way to do things is really to have a constant directivity, which means a falling response at high frequencies. But in an active system, this can be crossovered/EQ'd out. In a passive system the horn (or waveguided tweeter) would generally be much more sensitive in the midrange than the woofer, and a high crossover frequency should flatten the overall response but with more constant directivity. That's what we are at long hallelujah last starting to see from some makers. Even finally in the budget realm (Monolith) where you can get so much benefit by deepening the plastic ring around a tweeter into a waveguide for minimal additional cost.

For dome tweeters loaded in to horns, it seems the thing to do is push the motor strength up in a way that in free air the upper end of the tweeter's frequency range is very sensitive and efficient, with a constantly rolling off response as the frequency goes down. When it's loaded into a CD horn, the response will flatten as the horn brings the sagging midrange response up.
Are there any dome tweeters specifically intended to be loaded into CD horns?

 

[miero]

PURIFI Tweeter:
- https://purifi-audio.com/blog/tech-notes-1/the-purifi-tweeter-project-part-1-15

 

[Tim Link]

PURIFI Tweeter:
- https://purifi-audio.com/blog/tech-notes-1/the-purifi-tweeter-project-part-1-15

Looks like a great project. They are going for smooth, resonant free response, but not necessarily flat response. The fact that it's intended to be adapatable to a variety of waveguides with different dispersion rates suggest it will still need EQ. Maybe it won't if you pick a particular dispersion rate.
I get the impression that there's some technical issue with trying to make a CD horn/driver combo that is actually flat.

This is supposedly a textbook excellent response. https://ampslab-spk.com/2021/05/03/h6512-jbl-2414-review/
I see a lot of roll-off.

 

[miero]

A.classic collapsing polar. In those cases, there are other designs that are clearly better than horn IMO.

There is a new 3D model available if you want to try constant polars:
- https://cults3d.com/en/3d-model/various/ath-a460d-stl-kit

 

[Bjorn]

Also a collapsing polar though not that bad as the other. So much measurements these days, but people don't understand them!

 

[miero]

These are only simulations of a new waveguide. But measurements of a real device are expected to match them very closely. We will see in couple of days.

It is being already assembled:
- https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7825438

 

[Tim Link]

Also a collapsing polar though not that bad as the other. So much measurements these days, but people don't understand them!

Does "collapsing polar" just mean the directivity gradually increases with frequency?