# LeCleach Sounds Lovely.



## Patrick Bateman (Sep 11, 2006)

For the first time in close to a decade, I built a horn this month. (Most of my projects have been waveguides lately.)

I built a LeCleach horn for a home audio project.

These things sound lovely. If anyone is interested in making some of these for a car, they're definitely worth a look.










This is the one I built. Too big for a car, but it's designed to go down to 300hz, so you could get away with one that was a fraction of this size if you were horn loading a compression driver.

When I first started building horns, way back in the 90s, I really liked how horns had a way of making it sound like you *weren't* listening to a car stereo. For instance, when listening to something like "Sweet Jane" by The Cowboy Junkies, you could really get a feel for what the recording space sounded like.

In all my years of building waveguides I'd kinda lost touched with that intimacy.

I think the reason that this happens is due to the very long depth of horns. A waveguide with 90 degrees of coverage and a twelve inch mouth is about six inches deep. A horn with a twelve inch mouth is about 20 inches deep. Due to the much longer depth, the wavefront is contained in the horn for a longer amount of time, and I think that has something to do with that 'intimacy' that the LeCleach does.

Long story short - the longer length seems to minimize a lot of early reflections.

Anyways, might be a fun project for someone who wants to try making their own horns. There's a lot of depth underneath the dash of a car, particularly if you can build the horns to fit the car.

Everything you need to model a LeCleach horn is in hornresp.


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## Elgrosso (Jun 15, 2013)

I'm thinking more and more about trying a jmlc 2000/1400 or 1000, whatever fits on dash.
Did you test them?


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## Patrick Bateman (Sep 11, 2006)

Yes, I made and tested a LaCleach horn.

A lot of my waveguides are influenced by his designs, but I haven't made a "true" LeCleach horn in a few years.

Basically I utilize a lot of those big fat roundovers you see in LeCleach designs.


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## Elgrosso (Jun 15, 2013)

Ok, did you test the short versions as well?

I’m thinking... we have two ways to try to control chaos in our car:
Either integrate as best as possible the horn/waveguide with the car panels (ex smoothing the transitions mouth to windshield/dash/pillar). So the sound-waves continue to expand smoothly once passed the edges of the mouth.

Or just better control the diffraction at the edges so less sound-waves directly hit these panels. With big round-over like you did on the homster, or here on Le Cléac'h horns.


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## Patrick Bateman (Sep 11, 2006)

Elgrosso said:


> Ok, did you test the short versions as well?
> 
> I’m thinking... we have two ways to try to control chaos in our car:
> Either integrate as best as possible the horn/waveguide with the car panels (ex smoothing the transitions mouth to windshield/dash/pillar). So the sound-waves continue to expand smoothly once passed the edges of the mouth.
> ...


Unfortunately the size gets crazy in a hurry.









Here's a set of LeCleach horns I heard a few years back. That's a tweeter horn!









The 'spherical' horn profile used by Avantgarde Acoustics is virtually identical to the LeCleach profile. Here's a full range Avantgarde setup. They're hyoooge.










I know you already know this, but the dash plays a huge part in the sound of a car audio horn, it basically forms the mouth.

You *could* use a "true" LeCleach in a car but the cutoff frequency would be very very high, like 4500hz for a unit that's 6" in diameter.


Again, not discouraging you, they DO sound lovely. But they're huge!


I could probably be convinced to 3D print some out of sheer curiosity. I know Autotech out of Poland sells some but they're way too big for car use.










For car audio, the obvious one to 'clone' would be the Iwata, basically make it 1/4 the size and move up the crossover to match.

Here's an Iwata demo here: AUTOTECH IWATA-600 & 300 Size Comparison - AVS Forum | Home Theater Discussions And Reviews


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## Patrick Bateman (Sep 11, 2006)

There's a GREAT quote on the Iwata thread that helps explain a lot of my design decisions when I build waveguides:

The "Iwata 215Be's" info and build thread - AVS Forum | Home Theater Discussions And Reviews

_I too hear a difference with the IWATAs. For me the IWATAs sound 'bigger' than do other horn systems that I have had. All too often with my previous horn systems I could close my eyes and with my ears successfully point to the horn as the source of the music. With the IWATAs it is a different story. I find the music much more engulfing and I can no longer close my eyes and see the horn as the source of the music. It is a much different presentation than what I had expected. Does that sound like a reasonable description?? I am not satisfied with my own words but lack a better ones to share._

I LOVE THIS QUOTE.

For years, I've been kind of obsessive about eliminating diffraction from my speakers and waveguides. I learned this from owning my Gedlee Summas. Basically they had this ENORMOUS cabinet but they sounded very "small", almost like you were listening to a little mini monitor.









Here's a pic of my Summas on the right and my Vandersteens on the left.

IMHO, the Summas disappear because of that big ass roundover on the baffle.










So I think that what Carl is describing when he listens to the Iwatas isn't cause by the profile of the horn, it's caused by the ROUNDOVER on the horn's exit.

But the roundover is also what makes the Iwata and the LeCleach so darn big.










And yes, my experiments in that "homster" thread were largely influenced by owning my Summas.










Note that you can largely duplicate the effect of a roundover by using sound-absorbing foam. Basically we're trying to clean up reflections. Charlie Hughes designed this one, I believe he was also working with Geddes, so there's a lot of cross pollination here, we're kinda 'standing on the shoulders of giants' so to speak.


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## Elgrosso (Jun 15, 2013)

Well I was more thinking baout the small version, 2000 or 1400:
JMLC-2000 - Horns by Auto-Tech
JMLC-1400 - Horns by Auto-Tech

Or even something like that:
SL1KHZ - Stereo Lab

10cm should be ok on dash, maybe a bit more if I cut it in few places.
It's anyway limited by space so over 2khz maybe more, might be a little too much "in my face" but it's fun to test.
Only thing is, compared to other waveguides around they are kind of expensive.

I just got few cheap waveguides from different places + some cheap loaded tweeters that I will disassemble. I will try on my dome tweeters. 
Like the monacor wg300:








It's almost as large but more shallow of course.

About the peavy, what is the effct of the foam exactly?
Its shape I can understand, but do the micro bubbles absorb some waves and smooth out diffractions in the same time?


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## thehatedguy (May 4, 2007)

Hughes was working for Peavey at the time he designed the quadratic throat wave guide. His company is local to where I work, but never been by the place.


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## Patrick Bateman (Sep 11, 2006)

Elgrosso said:


> Well I was more thinking baout the small version, 2000 or 1400:
> JMLC-2000 - Horns by Auto-Tech
> JMLC-1400 - Horns by Auto-Tech
> 
> ...


The foam in the Peavey horn acts as an acoustic filter. There's a bunch of different ways to absorb air, foam is one of them. You can use closed cell foam, open cell foam, fiberglass insulation, and felt. IIRC, closed cell foam and fiberglass insulation are the most aggressive ways to absorb air. Open cell foam is on the opposite end of the spectrum; an entire foot of open cell foam only attenuates sound a few dBs. 

So basically you put the closed cell foam in places where you want to attenuate the sound. In the case of Peavey, they're putting it where the diffraction happens, at the transition from the mouth of the horn into the room itself. 

One of the main reasons I stopped messing with Lecleach was because the JBL progressive transition waveguides had impulse response that's very good. This is one of the areas that LeCleach is supposed to excel at; it's impulse response should be exceptional. (If you simulate a conical horn and a LeCleach horn in Hornresp, you'll see that the LeCleach excels at impulse response.)

One of my 'Eureka' moments in simulating the M2 waveguide (1) was the realization that the M2 waveguide behaves quite a bit like a conventional horn *while also behaving like a waveguide.*

Let me see if I can explain this, it's confusing:










Here's the expansion rate of a bunch of horn types. You can see that conical expands really quickly, and the 'traditional' horn types like exponential, *they expand slowly.* Both types have their advantages and disadvantages. Conical has really even coverage, but lousy impulse response. Exponential has great impulse response, but the coverage isn't even at all.










The M2 is basically a combination of both. On the orthogonals, it's a conical horn, on the X and the Y axis it's a diffraction horn. My 'hunch' is that the good impulse response of the LeCleach and exponential horns may relate to the expansion rate of the horn. If that is true, then it explains why the JBL progressive transition waveguides have good impulse response, better than you'd expect. (The JBL PT waveguides are just a less-extreme version of the M2 waveguides.)

(1) JBL M2 for The Poors - Page 49 - diyAudio


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## Patrick Bateman (Sep 11, 2006)

thehatedguy said:


> Hughes was working for Peavey at the time he designed the quadratic throat wave guide. His company is local to where I work, but never been by the place.


Are you in the 'Speaker Freakers' Facebook group? Charlie posts there on occasion.


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## Elgrosso (Jun 15, 2013)

Thanks PB, are you sure about ccf VS ocf or did you mix them up? I always thought open was a better sound "absorber"


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