Horning a cone-based midrange driver...

[Lee in Montreal]

I read a few articles on Dr Edgar's experimentations with making horns around a cone-based midrange driver. It looks like his main target was efficiency. Basically using a tractrix-shaped horn, and if there was no rear enclosure, then the pavillon's circumferrence would be the legnth of the lowest frequency wave (that makes for a huge unit if the cut-off target is 180Hz) for the system to work as a dipole.

Am I tempted having some fun trying things around a 5" JBL 104H-2 driver (which I just purchased and should soon get).

What are your thoughts on the subject? BTW Not wanting to be too specific yet about the system, but it will be crossed over at a 7K to a 2405 on top, and to 180Hz at the bottom to a pair of 2225h in 4530 bins. I am enjoying music in my house, so no PA system here. I also run two 2235h subs for the 20Hz-60Hz feel. Everything is driven by multi amps (Adcom 5500, Yamaha P2200, Rotel and Technics SE-9060) and an active crossover.



Could be fun to do some woodwork

http://forums.klipsch.com/forums/t/8...px?PageIndex=2

[Ruediger]

... see funktion-one.

Ruediger

[louped garouv]

... see funktion-one.

Ruediger

older EAW designs have utilized the phase plugs also,
as well as the "DD" horn by RLA

see the horn on the left here...
http://www.wavemusic.com/community/a...3&d=1161920566

[Lee in Montreal]

Hmmm... Before I start making mid horns with a big dick in its center, I will start with something more simple... ;-) Just trying to understand how a horn will affect frequencies.

[Mr. Widget]

Hmmm... Before I start making mid horns with a big dick in its center, I will start with something more simple... ;-) Just trying to understand how a horn will affect frequencies.

Horns have an upper and lower cut off frequency. I am not sure what would be the best compromise for a single horn/driver to run over the entire 180Hz to 7KHz range. There were numerous "full range" horns back in the early days of audio, but in the high fidelity era this broad spectrum is usually divided among multiple horns and drivers.


Widget

[Eaulive]

I'm elaborating a plan for a midbass front loaded horn with a 12" B&C driver, it's still in the design phase but I should build it next summer, I'll keep you posted.
It's sized to fit on top of the 4520 cabinet, I want to use the 4520 in the lowest region before the phase cancellation begins, around 130Hz, and then go with this horn until around 800Hz.

As far as I understand, the phase plug is working in the upper portion of the bandwidth and has little o no effect in the lower cutoff region.... but I may be wrong

[Lee in Montreal]

... I want to use the 4520 in the lowest region before the phase cancellation begins, around 130Hz...

That is my dilemna too with the 4530. I love the bass below 130Hz, then it starts being "vague" and too plentyfull North of 130Hz for home audio. I guess I might simply get a DCX2496 and cut at 200Hz while attenuating the 130-200Hz area. There are very few drivers than can cover 180Hz to 7khz where the 2405is crossed over. and trully, if I can avoid a four way system, I will be happy. The 2402 goes as low as 3.5KHz but dies at 15KHz...

[Mr. Widget]

There are very few drivers than can cover 180Hz to 7khz where the 2405is crossed over. and trully, if I can avoid a four way system, I will be happy. The 2402 goes as low as 3.5KHz but dies at 15KHz...

The best drivers capable of 180Hz to 7 or more kilohertz that come to mind are tall ribbons, electrostatic panels, or other planar devices. None of them are as dynamic as a horn loaded cone or compression driver though.


Widget

[yggdrasil]

One possible problem though is the higher frequencies.

The driver will need a very strong motor, if not, you will see an early roll off.

[Lee in Montreal]

I bought a pair of 104H-2 which seems to cover a wide enough range. Seems to be okay between 200Hz and 7KHz. And as I won't use it for PA, the small 40W power handling doesn't matter.

[subwoof]

The cone midrange will need to be in a small sealed chamber to balance the air resistance of the horn load otherwise the cone will develop an offset.

Back in the 80's I made 12" ( 2202A ) horn loaded cabs for the big nightclub systems and used the 2343 horn ( from the 2395 lens ) for a HF. For sizzle 2402's were mounted inside the horn. The cab is 24" square and designed to park on top of a 4530.

I still have one pair of those parked in the storage and it was converted to the newer 238X horn sometime down the road.

If you want a plug + play alternative, look at these molded mf/hf assemblies.

http://www.jblproservice.com/pdf/AE%...6315,95-WH.pdf

http://www.jblproservice.com/pdf/AS%20Series/CS3115.pdf

Just make a simple box and go.

I have a pair of each ( used ) but need a few internal parts for the 1.5 ones...

And I think the crossovers exist but have not unpacked everything yet.

[macaroonie]

There is enough info in this link to make your head spin. LE5 is discussed

http://www.volvotreter.de/downloads/...range-Horn.pdf

If you do an image search for Edgar mid horn you will find this and lots more :-

[Lee in Montreal]

There is enough info in this link to make your head spin. LE5 is discussed

http://www.volvotreter.de/downloads/...range-Horn.pdf

That was the first hit I got when searching and read thru DrEdgar's papers.

Thanks

PS How are your "new" JBL Professional Series speakers ;-)

[Ruediger]

I just added a paper from D.B. Keele to the technical references thread: LF horn design using TS parameters.

Ruediger

[DavidF]

I bought a pair of 104H-2 which seems to cover a wide enough range. Seems to be okay between 200Hz and 7KHz. And as I won't use it for PA, the small 40W power handling doesn't matter.

Low cut of 200Hz is about an octave too low per the original Edgar horn and JBL mid driver in the article. I would think you need a much longer horn and perhaps an exponential configuration to get a response that low.