• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Horns - Necessary to complete the Audiophile Journey?

mhardy6647

Major Contributor
Joined
Dec 12, 2019
Messages
1,407
Likes
2,067
and had Visonik Davids (anyone remember them?)
Yes, quite well -- the original "minispeaker" (of the modern era) and "inspiration" for the Radio Shack "Minimus 7".
Oft paired with M&K's "Goliath" subwoofer, and to good effect.

The small ads loudspeakers of the time (L-200, L-300, e.g.) were, to me, somewhat better overall (and somewhat larger, too, if memory serves).

I wouldn't mind having a pair of LS3/5A-spec monitors -- but they're a little pricey and not really on my main axis of hifi wants or needs or whatever.
 

Eurasian

Active Member
Forum Donor
Joined
Nov 2, 2018
Messages
168
Likes
106
You should get them too. I might be the only person in the universe who bought them for their extended bass. I was living in a tiny house - living room literally 8' wide - and had Visonik Davids (anyone remember them?) Swapping in the LS3/5as was like adding a subwoofer.
And I had a Goliath subwoofer!
 

Sal1950

Major Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
7,824
Likes
6,408
Location
Central Fl
Peter doesn't do things halfway, does he?
He sure as h-ll don't. It just confuses me a bit that he doesn't seem to have allegiance to any one speaker design.
Looks that he builds just about every type out there except panels, that scares me a bit.
More marketing focused rather than excellence? IDK

My interest has gotten the better of me. I've just ordered 2 JBL Eon 615s.
I can't wait to hear what you think of them. The numbers tell me they can't possibly be as bad as @watchnerd believes them to be. ???

My 9th loudspeaker purchase in the past couple months :facepalm:.
WHAT? OMG LOL

Perhaps I'll just throw in the towel on horns and get these, instead, to complete my audiophile bucket list:
LS3/5a the worlds most popular British WIMP speaker. :eek: They should all be connected to a SAE 1KW amp and driven till they let the smoke out. Along with AR 3s
LOL JK
 

Sal1950

Major Contributor
The Chicago Crusher
Forum Donor
Joined
Mar 1, 2016
Messages
7,824
Likes
6,408
Location
Central Fl
Joined
Jan 28, 2017
Messages
30
Likes
30
In answer to the OP's question, I'd say, "It depends on several factors":
- Your room
- Distance to listening position
- WAF> size matters
- Objectives related to directivity, bandwidth, SPL etc.

Studying horn technology is recommended to get a better idea of what's possible.
For example, you may discover that some modern compression drivers can easily compete with the best dome tweeters for significantly less money.
 

Duke

Senior Member
Manufacturer
Forum Donor
Joined
Apr 22, 2016
Messages
344
Likes
621
Location
Princeton, Texas
It just confuses me a bit that he doesn't seem to have allegiance to any one speaker design.
Looks that he builds just about every type out there except panels, that scares me a bit.
More marketing focused rather than excellence? IDK
Eyeballing the M series, my GUESS is that Peter is exploring the upper ends of two different high-output mid/high frequency technologies: Waveguides and ribbons.

In his larger designs I see attention being paid to radiation pattern, but using different puzzle pieces: Cone 'n' dome; cone 'n' waveguide; cone 'n' ribbon.

I have used the same waveguide Peter is using in the M1!5 in many different models. It is inexpensive and looks that way but performs very well. The M1!5 is obviously not an inexpensive speaker, so imo he is using that waveguide for its performance and not for its audiophile eye-candy appeal.
 
Last edited:
OP
watchnerd

watchnerd

Major Contributor
Joined
Dec 8, 2016
Messages
8,574
Likes
5,076
Location
Seattle Area, USA
Thread Starter #349
Eyeballing the M series, my GUESS is that Peter is exploring the upper ends of two different high-output mid/high frequency technologies: Waveguides and ribbons.

In his larger designs I see attention being paid to radiation pattern, but using different puzzle pieces: Cone 'n' dome; cone 'n' waveguide; cone 'n' ribbon.
I'm curious why the same speaker seems to come in a wave-guide-on-top and wave-guide-in-the-middle version.
 

Duke

Senior Member
Manufacturer
Forum Donor
Joined
Apr 22, 2016
Messages
344
Likes
621
Location
Princeton, Texas
I'm curious why the same speaker seems to come in a wave-guide-on-top and wave-guide-in-the-middle version.
MHM offers vertical symmetry, but if your ears aren't near the correct vertical height, the midwoofer lobing errors are worse. HMM is more forgiving. And eyeballing the cabinets, my guess is that there's a significant upcharge for the MHM version.

Since in this case it looks like the MHM version has the horn up high enough to be around seated ear height, that's the one I'd be inclined towards, pending Peter's recommendation. The relatively low crossover (900 Hz) means that your localization perceptions will be dominated by the horn so HMM would also work, but imo there is an argument to be made for the theoretically simultaneous arrival times of the two midwoofers in MHM configuration.

There are other considerations (including floor and ceiling interactions), but imo they are not dominant factors.

I have used both formats, albeit with a higher crossover frequency: MHM for big stand-mounted custom studio monitors where ear location was known in advance to within a few inches; and HMM for home audio speakers. Thumbnails attached. Neither one is currently offered, so these images are of academic interest only.

In the MHM studio monitors, I'm using the same waveguide-style horn that Peter uses in his M1!5. Notice how the tilt aims the speakers at the ears of the invisible engineer in the mixing chair. In the HMM home audio speaker, I'm using a SEOS (Super Elliptical Oblate Spheroid) waveguide-style horn from DIY Sound Group.
 

Attachments

Last edited:
OP
watchnerd

watchnerd

Major Contributor
Joined
Dec 8, 2016
Messages
8,574
Likes
5,076
Location
Seattle Area, USA
Thread Starter #351
There seems to be a hobbyist community around using TAD drivers with wooden bi-radial horns:





They sure look amazing.

But are there any technical merits / de-merits to these kind of horns versus other shapes?

Speaking of which....

Is there a primer somewhere on horn geometry?
 

Duke

Senior Member
Manufacturer
Forum Donor
Joined
Apr 22, 2016
Messages
344
Likes
621
Location
Princeton, Texas
There seems to be a hobbyist community around using TAD drivers with wooden bi-radial horns...

They sure look amazing.

But are there any technical merits / de-merits to these kind of horns versus other shapes?
Eyeballing those TAD horns, my guess is that their radiation pattern width is a full 90 degrees in the horizontal plane over most if not all of their spectrum, with the little "vanes" helping out in this regard at high frequencies. In the vertical plane I'd guess that the radiation pattern is considerably wider at the bottom end of the spectrum than at the top end. The part of the horn deep inside, back near the throat, is what controls the vertical pattern at high frequencies, and it looks to me like the top and bottom of the horn are virtually parallel back there, implying a tight vertical pattern. Then as we go down in frequency (as the wavelengths become longer), the pattern starts to be controlled more by the mouth-end of the horn, so it widens, at least in the vertical. But I could be wrong; there could be other things going on which I haven't taken into account.

As for potential sources of coloration, I like the big round-overs of the "lips" but am not a fan of the relatively sharp edges at the "corners" of the mouth. I'm not sure what the coloration implications of the "vanes" are; in general reflections within a horn are undesirable in my opinion.

But they sure do look awesome!!

Speaking of which....

Is there a primer somewhere on horn geometry?
The Wikipedia article looks pretty good to me.

On another forum Jack Bouska examined some of the qualitative issues around horn design. These two posts are imo the most instructional. Note that the abbreviation "CD" herein stands for "constant directivity", not "compression driver" or "compact disc":

http://www.audioheritage.org/vbulle...amp-Waveguides&p=132741&viewfull=1#post132741

http://www.audioheritage.org/vbulle...amp-Waveguides&p=132743&viewfull=1#post132743

Getting back to the TAD horns for a minute, they are designed for "old school" compression drivers which have a long internal throat with a relatively narrow flare angle. Such compression drivers generally do not work well on more modern waveguide-style horn shapes, such as the Quadratic Throat and Oblate Spheroid, nor on the more recent generation of JBL waveguide-style horns (which came along after Bouska's posts). These more modern, low-coloration, constant-directivity waveguide-style horns work best with modern compression drivers having a much shorter internal throat. Imo ideally the exit angle of the compression driver matches the entry angle of the horn, to avoid a diffractive discontinuity where they meet.

This website has useful polar maps of some of their horns: http://horns-diy.pl/. Let's look at a couple of radiation patterns.

The SEOS 12 (which was used in one of my thumbnailed designs in Post #350) is an approximately constant-directivity design. You can see that in the (narrower) vertical plane it starts losing pattern control around 2 kHz, whereas in the (wider) horizontal plane its pattern control is good for another octave or so. The pattern widening in the vertical plane is because the rectangular horn is physically too small in that dimension to maintain good pattern control below 2 kHz or so. However it's close enough that the off-axis sound has approximately the same spectral balance as the on-axis sound, out to the pattern's -6 dB limits (90 degrees horizontal, and ballpark 45 degrees vertical over most of the spectrum). When using this type of horn, I like to dip the on-axis response just a little bit south of 2 kHz to offset that excess vertical off-axis energy.

The J. M. LeCleac'h horn is clearly not a constant-directivity design; as you can see, the pattern becomes increasingly narrow as we go up in frequency. This simplifies crossover design AND results in considerably higher on-axis efficiency, as the top octave is usually the limiting factor, so by concentrating the energy into a narrow angle the sound PRESSURE level is higher within that narrow pattern. (Think of a variable nozzle garden hose: The same amount of water comes out regardless of the pattern width, but the PRESSURE where it hits is higher with the narrow pattern.) The downside is, that the off-axis sound has a significantly different spectral balance from the on-axis sound. So we are unlikely to see JBL using LeCleac'h horns any time soon. Note that JBL went to great lengths in the M2 waveguide to get an exceptionally wide radiation pattern (especially for a 1.5" throat compression driver) all the way up the spectrum, but that the broadband efficiency of the M2 is not particularly high for a large horn loudspeaker (92 dB).

The closest thing to a TRUE constant-directivity device on that website is probably the 15" Oblate Spheroid, but no measurements are shown on its page.

So if you want to use a flea-powered tube amp, you probably either want a horn which concentrates the top-octave energy into a narrow angle, or you want an additional small horn (tweeter or super-tweeter) to handle the very top end. If you don't mind having more modest efficiency, then you can use a constant-directivity horn to cover the entire upper portion of the spectrum. Typically 1" throat compression drivers have more top-octave energy than large-format (1.4", 1,5" and 2") compression drivers, so it is usually more cost-effective to run the midwoofer up a bit higher and cross over to a 1" throat compression driver, the GedLee Summa being an arguably advanced example of such (which to the best of my knowledge was never tested by Harman). But there are also arguments for going a bit lower and covering everything from ballpark 800 Hz on up with a single driver, hence designs like the JBL M2 and the beautiful DIY TADs in your photos.

Sorry for the rambling post, I'm winging it.
 
Last edited:

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,004
Likes
1,555
Location
Oxford, England
Sorry, I misinterpreted what you said. Still, I think they are an interesting science experiment.
I didn't say it either, though PA speakers I've hear have not sounded particular adequate for domestic playback (even though some were really good when playing at "live" levels).
 

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,004
Likes
1,555
Location
Oxford, England
The J. M. LeCleac'h horn is clearly not a constant-directivity design; as you can see, the pattern becomes increasingly narrow as we go up in frequency. This simplifies crossover design AND results in considerably higher on-axis efficiency, as the top octave is usually the limiting factor, so by concentrating the energy into a narrow angle the sound PRESSURE level is higher within that narrow pattern. (Think of a variable nozzle garden hose: The same amount of water comes out regardless of the pattern width, but the PRESSURE where it hits is higher with the narrow pattern.) The downside is, that the off-axis sound has a significantly different spectral balance from the on-axis sound. So we are unlikely to see JBL using LeCleac'h horns any time soon. Note that JBL went to great lengths in the M2 waveguide to get an exceptionally wide radiation pattern (especially for a 1.5" throat compression driver) all the way up the spectrum, but that the broadband efficiency of the M2 is not particularly high for a large horn loudspeaker (92 dB).
People generally object to this but I think that a distinction should be made between wide- constant-directivity low-gain (primarily) waveguides and horns (which in my view are a particular kind of waveguide).


Horns are meant to be used in a multi- ≥4-way configuration.
 

Duke

Senior Member
Manufacturer
Forum Donor
Joined
Apr 22, 2016
Messages
344
Likes
621
Location
Princeton, Texas
People generally object to this but I think that a distinction should be made between wide- constant-directivity low-gain (primarily) waveguides and horns (which in my view are a particular kind of waveguide).

Horns are meant to be used in a multi- ≥4-way configuration.
Yes, I should have made the distinction between high-gain devices (horns) and low-gain devices primarily designed for pattern control (waveguides). Thanks for catching that!

And because of the limited bandwidth across which a horn optimally increases gain, very high-efficiency horn systems often do have four or more "ways".

Nor did I mention midbass and bass horns, which are large and huge, respectively, and whose depth introduces time-alignment issues (which can be addressed in the digital domain, if one is so inclined).
 

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,004
Likes
1,555
Location
Oxford, England

Attachments

Last edited:

Duke

Senior Member
Manufacturer
Forum Donor
Joined
Apr 22, 2016
Messages
344
Likes
621
Location
Princeton, Texas
Something else which might be worth pointing out, brought to mind by tuga's posts just above:

Constant-directivity waveguide-style horns typically have tight-radius curves near the throat, with the rate of curvature decreasing towards the mouth (not counting the mouth round-over itself).

Non-constant-directivity horns typically have very gentle curvature near the throat, with the curvature tightening towards the mouth, sometimes even extending smoothly into the "lips" around the mouth, as in the case of the LeCleac'h horn.

In this family of curves, the blue is the Quadratic Throat and the lavender is the Oblate Spheroid. You can see that these two have most of their curvature near the throat, while that is not true of any of the others. I copied this image from one of Jack Bouska's posts:

HornProfiles.JPG
 

tuga

Major Contributor
Forum Donor
Joined
Feb 5, 2020
Messages
2,004
Likes
1,555
Location
Oxford, England
There seems to be a hobbyist community around using TAD drivers with wooden bi-radial horns:





They sure look amazing.

But are there any technical merits / de-merits to these kind of horns versus other shapes?

Speaking of which....

Is there a primer somewhere on horn geometry?
I dived into horns with something similar but with 12" woofer and cheaper chinese drivers, bough ex-demo from the distributor at 40% off.
Started with this 2-way:



Then converted it into this 3-way adding a Visaton horn tweeter and replacing the original horn with a tractrix.
(the overly-tall horn stand is a temporary prototype, made of Ikea leftover plywood drawers)


Then got fed up with the permanent work-in-progress tweaking and as it needed a new woofer and was getting too expensive I sold them.
 

Similar threads

Top Bottom