(Inspired by Ron) ibR 108 horn

[Leonidas]

After building 4 or more times a concerti 108 clone I decided on a new horn , being insired by the way Ron folds the 126 horns.
This because the "frugel"horn design was to low for my ears.
I'm working on a detailed drawing, if anyone is in need for it.
Because I also did a group build with children I was able to compare the concerti clone to the ibR 108 horn.
The ibR wins by a large marge!!
Don't do to much posting but this one is really nice, even compared 2 my lowther dx3 on OB.

[rjbond3rd]

Hi Leonidas, very nice! Please do post your plans when you are able.

1. What does ibR stand for?
2. Can you tell us a bit about how you calculated it?

[Leonidas]

To rjbond3rd,

1 i(nspired) b(y) R(on) 108 horn.
Ron Clark did several designs, all of them "feel"good. But no specific
fe108ez design.

2 Did a lot of reading about the 108;
Vc between 1,5 and 2,5 Liter , in my design 2,78L , adjusted with styroporblock to 1,9 liter.Sounds the best in my room.
Line lenght 1,8 m and more , even some Japanese designs were 2,7 m.
my line is 2,2m.
Throath is 80% cone surface.

Then I simmed everything in hornresp and compared the results with things I builded before.
When everything looked promising I started building them.
They are supposed to be corner loaded.
They sound a lot better then the sims predict!!
Stil working on a deflector and a small fronthorn (NO supra baffle!!)
Will update as soon as possible (asap?? ; Im Dutch)
They measure 90x20x36cm.

[rjbond3rd]

Hi Leonidas, ibR -- I get it! Your work is very impressive.

So the second box is the Concerti clone. If I may ask, what is the third box, with the port opening? Did that do better than the Concerti clone?

[Scottmoose]

Ron did start on a design for the FE108ESigma, but abandoned it after a few months; IIRC he wasn't happy about the limited uncompressed dynamic BW of the driver, so it was never finished.

[Leonidas]

rjbond3rd : thank's for the compliment. I like to be productive.
The "spiral"design was something inbetween; Gemme audio do athing they call V-flex. As I understood this is a horn with a port at the mouth. So I wanted to know how audible an irregular CC was and at the same time how a port at the mouth sounded.
BTW MINE HAVE TWO PORTS, ONE AT THE RIGHT AND ONE AT TH LEFT SIDE (YOU CAN SEE STRAITH THROUG= FUNNY LOOKING)
My ears tell me that a triangular shape sounds better in the midrange.
I started with two small (5cm dia) holes and enlarged them until everything sounds best to my ears. Strangely that was when the two holes together were about half of the mouth size.(don't know how to explain exactly).
ibR 108 horn has better lows, But the "spiral-horn" made two women to cry when they played Susan Doyle.(not me)
ibR gives me goose skin at some cd's

Thank's to Scoot for his remark, I was unaware of Ron's effort.
Did Ron build reel proto's or did he only calculate/simmed?

I'm unaware of any compression : the kids had some cd's with them and they all agreed on a large "life-effect" (Muse-Resistance , Leonard Cohen-Life in London)
My room is 5.6x3.75x2.5 m. So not to big.
I don't listen to large orchestra's but more Norah Jones, Akoustic guitar Miles Davis and that kind of stuf.

[Scottmoose]

AFAIK, he never got to prototype stage; as I say, IIRC, he was never happy with the limited dynamic BW.

Gemme Audio's VFlex is basically marketing speak for 'mass loaded horn' where the terminus cross-section is choked down (as you have done with your box too).

[chrisb]

Originally Posted by Scottmoose

AFAIK, he never got to prototype stage; as I say, IIRC, he was never happy with the limited dynamic BW.

Gemme Audio's VFlex is basically marketing speak for 'mass loaded horn' where the terminus cross-section is choked down (as you have done with your box too).

Had a chance to see & hear a pair of these a while back - very pretty boxes, the sound was "OK" too - and even better with EnABLed drivers

[Leonidas]

To chrisb,

I found it a strange experience that the Gemme hole is that small.
If you have seen them in reel life ( I only saw pictures)
Have you seen anything like a pipe, or is there just a hole?
Mine sound best with 2x112cm diam. hole.
My "spiral-horn" is also for corner loading and the Vflex is freestanding, could that explain the difference??

[Leonidas]

BTW I promised planet 10 the drawings as soon as I finished them for his site.
Assuming that Ron agrees and is not offended in any way.

For rjbond3rd an attachment: the concerti 108 clone.
Basicly it's like the fostex rec. design but we made it more smooth with halfround and triangular hardwood in the first narrow part of the horn.
Expecting to get more acceleration over there.
Scott once mentioned the function of the 90 degrees parts, so we left that intact in the last part of the horn.
The Vc is aprox. 2,7 L , fits the fe126e , and has to be adjusted to 1.8~1,9 L for the 108. I use the circular piece loudspeaker cut-out , and put it inside the Vc , with is about right and tweak the rest by ear.
They really sound dynamic on low level, but I never heard the reel Gemme's.

One remark: I try to get MY SOUND , witch means that I cannot garantie anyone else likes my designs!!