Are Iwata horns that good?

[Lee in Montreal]

52200
52201
52202
52203
52204

Is that Iwata horn that good? Strangely, I can't get any response graphs.
How better than, say, a similarly sized 2350.

[spkrman57]

But they sure do look pretty!!!

Regards, Ron

[Lee in Montreal]

But they sure do look pretty!!!

Regards, Ron

And these are beast at around 30" wide x 24" deep x 14" tall.

Currently transforming the above drawings into cercles and elipses that CAD can understand. CAD softwares don't understand Bezier curves, so I have to find simple equivalent circular shapes. But that part is done. Then on to find ways to stack wood to avoid losses of material and excessively heavy horns.

Imtermediate stage of draft. The original (can be seen in blue) is approximativee and specs/measures don't match the drawing. No to mention the lack of symetry on a draft done by hand 25 years ago... )

52205

[Lee in Montreal]

The joys of making dust. Some guy's making an Iwata horn.

http://www.youtube.com/watch?v=2MFcTfjeMI0

If I had to do it, I'd machine the sides at the same time. Top and bottom being the same, just make holes for dovel pins and you get a complete horn out of two similar parts as has been done by others. Except that I would also machine the bottoms and tops to make lighter horns.

[polar_bear_0104]

very interesting. thanks for sharing lee...i'm interested to find out too...i've encountered a few iwatas too but have not had long time with them to form an opinion.

[richluvsound]

Great project .

thanks for posting it .

Rich

[carolus]

52200
..... Is that Iwata horn that good? ....

Hi Lee,
FYI,
I build those Iwata (4units) in 1983 in DIM ..... with wood multilayer, concept in slices .... with 10cm adaptor from 2" square to 2" round ....
In 5-way-horn concept,
See (Iwata) publication "L'audiophile N°21 & 25" ...
Do-it,
It's beautifull music .....
Allez, salukes & ... best regards,
Karel

[Lee in Montreal]

I build those Iwata (4units) in 1983 in DIM

Hi Karel

Do you have pictures of them? Please let us know what is "DIM"... ;)

On another note, a Polish supplier is producing fiberglass horns. Here's an Iwata 300. I wonder about the material's resonance. Using fiberglass is a very cheap way to produce horns too. The hardest (and most expensive) part is making the original mold. Then copies are a walk in the park. MrWidget seems to have been succesfull with polyurethane plastic I believe.

52220
52221

[stephane RAME]

http://www.horns.pl/iwata300wh4.html

Stéphane

[Lee in Montreal]

http://www.horns.pl/iwata300wh4.html

Stéphane

Thanks Stéphane. Also a bunch of American dudes from AVSaudio.com just bought a huge pallet of horns from this outlet. I am waiting for them to start sharing their feedbacks.

http://www.avsforum.com/avs-vb/showthread.php?t=1336262

52222
52223

[carolus]

Do you have pictures of them? Please let us know what is "DIM"... ;)

On another note, a Polish supplier is producing fiberglass horns. Here's an Iwata 300. I wonder about the material's resonance. Using fiberglass is a very cheap way to produce horns too. The hardest (and most expensive) part is making the original mold. Then copies are a walk in the park. MrWidget seems to have been succesfull with polyurethane plastic I believe.


Hi Lee,
See photo ... my Iwata(-s) anno 1983, material: wood-multilayers-18mm-glued, it's "amorphe" (believe me) ...
In DIM, read "did it myself" (or DIY) ...
I am very satisfied ... no need to change my modest montage .....
Indeed, the Iwata300 is more "recent"
Best regards,
Karel
https://lh3.googleusercontent.com/-bkKqRnqu03E/Ti--pkNpoII/AAAAAAAAECc/zal43kTH-yY/s800/_DSC4672.JPG

[yggdrasil]

Hi Karel.

Is that a small Iwata for 1" driver you have on top there?

Do you know of more documentation / drawings for Iwata's. The only drawing I have found is the one Lee posted in #1.

[Lee in Montreal]

Yuichi's Audio Lab has many drawing available too.

http://www.geocities.jp/arai401204/

[yggdrasil]

Thanks Lee.

I am a big fan of Yuichi's horns. They look simply amazing. Haven't yet built any of his designs, but I have used the same ideas to build a version for 1.5" drivers.

Johnny

[Lee in Montreal]

Thanks Lee.

I am a big fan of Yuichi's horns. They look simply amazing. Haven't yet built any of his designs, but I have used the same ideas to build a version for 1.5" drivers.

Johnny

Yup.Yuchi's horns seem to be easy to produce.

BTW I am just off the phone with a one-guy wood shop. I will supply drawings today and we are going to see what can be done to produce a pair of Iwatas. The good thing is that the guy does CNC machined sculptures and restaurant signs as an artisan. So, while a part is being machined, he can spend that time sanding and finishing existing parts instead of watching the bit make saw dust :D Basically, I can simply send him drawings, and then pick-up fully assembled units. Also, one of my goals on this production of a prototype is to make the horns lighter than the bulkier ones we usually see posted.

[Carl_Huff]

I bought a pair of the Polish IWATA 300 fiberglass horns. That's a JBL 2035 driver below it in a stock JBL Cinema cabinet. I am really, really pleased with how nice these sound! In my case I am using JBL 2446H compression drivers loaded with aftermarket 'cheapy' aluminum diaphragms crossed at 24dB per octave at 550Hz. I am toying with the idea of buying a pair of Truextent beryllium diaphragms.

http://theeasyview.com/members/carl_huff/PIC_01_20110703175227.JPG

http://theeasyview.com/members/carl_huff/PIC_04_20110703175221.JPG

I used an AP20 as active crossover and Dirac Live to optimize the room. below are the before and after room plots. As you can see a super tweeter could be easily justified, but even without the end result is very pleasant to listen to.

http://theeasyview.com/members/carl_huff/FREQUENCY_20110703175223.jpg

http://theeasyview.com/members/carl_huff/IMPULSE_20110703175224.jpg
____________
Best Regards,
Carl Huff

[louped garouv]

of my goals on this production of a prototype is to make the horns lighter than the bulkier ones we usually see posted.

have you seen some of the Fostex designs?
I have a pair of H425s (in need of repair) that seem much lighter than the 350Hz edgarhorns I am using...

here's a post with brochure posting of the Fostex line...
http://www.audioheritage.org/vbulletin/showthread.php?5229-Mystery-Large-Format-Monitors&p=225774&viewfull=1#post225774

[Mr. Widget]

I have a couple of questions... does anyone know the sonic differences between the flat sided wood and the swept back sided fiberglass Iwata 300 horns? I assume the fiberglass horns have this shape because it is supposed to reduce diffraction and edge termination issues, but in real terms what does it do?

Carl, how dense is your horn? Free floating like that, and with that type of geometry, free floating is about the only way you can use them, but free floating, I have to think they must ring a some level.

Lee, thanks for posting the AVS link... very interesting. I wasn't aware of these fiberglass horns. They look well made and seem to be a nice low to moderately priced source for horns.

From my experience playing with fairly dense and inert horns, there are measurable and audible differences between lower mass free floating horns and massive horns that are baffle mounted.


Widget

[Carl_Huff]

I have a couple of questions... does anyone know the sonic differences between the flat sided wood and the swept back sided fiberglass Iwata 300 horns? I assume the fiberglass horns have this shape because it is supposed to reduce diffraction and edge termination issues, but in real terms what does it do?

This is an elliptical horn. It does not sound like any horn that I have heard before. It's presentation is wide and coverage is even. You can walk about the room and not hear the boundaries from left to right that I had expected to hear.

http://diysoundgroup.com/IwataWG.htm



Carl, how dense is your horn? Free floating like that, and with that type of geometry, free floating is about the only way you can use them, but free floating, I have to think they must ring a some level ...

From my experience playing with fairly dense and inert horns, there are measurable and audible differences between lower mass free floating horns and massive horns that are baffle mounted.

The fiberglass is surprisingly dense. When you rap on the body of the horn with your knuckles you hear more of a thud than a ring. The character of that 'thud' does change slightly as you move from throat to mouth. But you are right, the horn might well benefit from having an acoustic dampening material applied to it. They are without a doubt more resonant that the same contour carved by CNC from a block of wood. I would be very interested in comparing them to one another.

My IWATA 300s are from the first group buy. They have since made some improvements. Newer horns have a metal mounting ring similar to that of the old Gauss fiberglass horns. Mine have an MDF ring. The metal ring is said to be stronger and affords more support to the horn body.
______________
Best Regards,
Carl Huff

[Lee in Montreal]

Here's a response graph I found off Phil Mundi's website. It is for a very simliar Iwata horn as the ones I am building, but with a mouth that seems to have a bit less horizontal opening. Nonetheless, it seems to me as it is a 400Hz horn if not a useable 300Hz (can a diaphragm safely widthstand such low frequencies in a home environement - aka low sound levels?). I am a bit surprised though at the upper cut-off. 9kHz? Could that be that Mundi is using non-stock 2441 diaphragms?

52248
52249

[Mr. Widget]

Nonetheless, it seems to me as it is a 400Hz horn if not a useable 300Hz (can a diaphragm safely widthstand such low frequencies in a home environement - aka low sound levels?).I'd expect the diaphragm to age more rapidly when asked to operate at such a low frequency even if you keep the levels quite moderate... more over, if you are concerned about sound quality, using a horn too low gives you that classic "horn" sound. I have found that if you use a 300Hz horn to 600Hz you will have a much more natural sounding horn that doesn't "honk" at you.


I am a bit surprised though at the upper cut-off. 9kHz? Could that be that Mundi is using non-stock 2441 diaphragms?Possibly, but I wouldn't count on it.

Small changes in the horn can have large changes in the performance... two horns that "look" the same may not be the same or sound the same. That said, many DIYers use vintage or used drivers and the performance of these drivers can differ widely from their specifications.


Widget

[Lee in Montreal]

The distance from the diaphragm to the mouth is 0.692m or 1/4 wave of 125Hz

The mouth is 0.158m tall by 0.935m with a total perimeter of 2.186m. Shouldn't it "allow" a 158Hz cut off? Therefore, I suspect that this horn could well work down to 400Hz "cleanly" if the driver allows it. These are only suspicions and only testing will tell. ;)

I found this, where the manufacturer claims it "can reproduce frequencies from 250Hz".
http://www.jgaudio-systems.com/lesnikov/produtos_iwata_en.html

[1audiohack]

Sadly what's nearly always missing from these graphs is the phase response. With that information, literally the other half of the picture, one can better determine if the driver simply can't produce the required / desired energy or it there is something else at play.

A properly functioning 2441 on a 2311 horn would tempt even me to run without a tweeter, put that same driver on a big Yuichi or the Iwata pictured or a 2360 and there's little hope in my mind the driver can deliver the energy needed to satisfy my requirements for HF. Even the 2397's frequency response curve sinks like a safe about 9.5 kHz.

[Lee in Montreal]

Yup. These are only physical measurements that don't take in account the specific shape of the horn, which is where reflections and nulls are eliminated, and will impact the audible bandwidth, not just the calculated one.

[cody_zox]

Where to find 3D model for making wooden Iwata horn on CNC machine? Can somebody help please? I need it to go as low as 250Hz or maybe 300Hz and not to be wider of 85cm in size.

[Lee in Montreal]

Where to find 3D model for making wooden Iwata horn on CNC machine? Can somebody help please? I need it to go as low as 250Hz or maybe 300Hz and not to be wider of 85cm in size.

There are plenty of 2D drawings on the internet. You can have the 3D model done from those 2D drawings.

[JoMoCo]

Now that Carl has lived with his IWATA fiberglass units for awhile maybe we could talk him into sharing .. some measurements perhaps ..
:cheers:

[Carl_Huff]

Now that Carl has lived with his IWATA fiberglass units for awhile maybe we could talk him into sharing .. some measurements perhaps .. :cheers:The PIC server that I had used in my previous post has since gone offline. Here is my latest use of the IWATA 300s.

55158 55159


55160

These are restored Altec 828 cabinets loaded with a new GPA 416-8C driver. And below is the amplitude response that comes out of them. This particular PIC is of the right channel. However the left is very similar.

55161

The 'Before' PIC is what what was measured using Dirac Live software tools running on my PC laptop. The red overlay was the target curve that I created. The 'After' PIC is what Dirac Live running in a Datasat RS20i was able to provide. I confirmed the After curve using RTA software measured at my favorite listening position. I really, really like the IWATAs! I use them every day.
________________
Best Regards,
Carl Huff

[Carl_Huff]

Just a quick update on my aging ALTEC 828 cabinets and IWATA 300 horns.

Thanks to our very own Widget I have recently acquired a pair of Truextent beryllium diaphragms for my JBL 2446H compression drivers. Within the last week I have mated them with my IWATA 300s and have spent the last few days tweaking the install. I am absolutely enamored with them! I am an aging (grumpy??) bugger that had grown cynical watching the published claims for new products and had been slow to buy them, but am now very glad that I did.

Truextent beryllium diaphragms and IWATA 300 horns are at the heart of my reference listening system.
_____________
Best Regards,
Carl Huff

[A Vanderkruk]

I have made several of the modified iwata 270 hz 400hz 600hz and 800hz all test very well and have the best home use sound stage coverage I have heard as well, I have to agree with the coments. My approach was to mould the top and bottom profile's and I made them with a sand epoxy composite, this is hard like granite and offers no stored energy is very relective and increase sensitivity and clean clean sounding.The side profile is wood veneer backed with composite, much more build time than fiberglass but worth it.5708857089

[Carl_Huff]

"... I made them with a sand epoxy composite ..."

Aah! Very nice!!

Please tell us more about how you built your horns. For example what 'sand epoxy composite' material did you use? I would like to experiment with that material myself.
_____________
Best Regards,
Carl Huff