1,4" or 2" horn for Faital HF206

[Defo]

Hello,

I have a pair of Faital Pro HF206 drivers which I want to buy horns for.
But the issue is - this driver is really a 1,4" exit with an 2" adapter fitted on as standard (with a 4 inch diaphram).

Which means that when using a normal 2" horn, the total horn length from actual driver exit will be slightly longer (about 3 cm) then intended.

Should I still go with a 2" horn, or a 1,4"?

 

[tinitus]

...... this driver is really a 1,4" exit with an 2" adapter fitted on as standard (with a 4 inch diaphram).

what ?

 

[fpitas]

I'm rather confused, too.

In any event, this is a very nice horn if you don't mind the narrowing dispersion at the high end:

Horns

I think they will make it 2" or 1.4" entrance, your choice.

 

[weltersys]

Hello,

I have a pair of Faital Pro HF206 drivers which I want to buy horns for.
But the issue is - this driver is really a 1,4" exit with an 2" adapter fitted on as standard (with a 4 inch diaphram).

Which means that when using a normal 2" horn, the total horn length from actual driver exit will be slightly longer (about 3 cm) then intended.

Should I still go with a 2" horn, or a 1,4"?

If you want even, wide dispersion out to 16 kHz (or so) the throat must be narrowed to 1" (or less).
Less "damage" (diffraction artifacts) occur narrowing a 1.4" to 1" than narrowing a 2" to 1", so the 1.4" is generally a better choice.

If you are planning to use it as a mid driver, say only up to 5 kHz, the choice is not as clear cut.

 

[Defo]

To address the confusion, see pic. It seems the driver is actually a HF146, but with an adapter expanding the throat to 2 inches.
I was rather suprised myself

If you want even, wide dispersion out to 16 kHz (or so) the throat must be narrowed to 1" (or less).
Less "damage" (diffraction artifacts) occur narrowing a 1.4" to 1" than narrowing a 2" to 1", so the 1.4" is generally a better choice.

If you are planning to use it as a mid driver, say only up to 5 kHz, the choice is not as clear cut.

I plan on using it "full range", that is 500hz and up. The horn will be of a spherical type.
It seems that going with the 1,4 inch throat is best, but that also means the horn will be longer, which could add more horn colorations, and theoretically will beam more with increasing frequency...

 

[fpitas]

That adapter looks like it has a pretty fast flare, and I doubt its throat angle will mate nicely to most horns. My choice would be to leave it off and use the driver on a 1.4" throat horn.

 

[POOH]

Using TAD 4002 that has the 1.5" to 2" snout I found with and without the snout in 400 Hz Edgar salad bowls the 1.5" was much better sounding. When compared with the full 2" exit 4001 the 4002 without the adaptor was much better too - here I was using the driver all the way up without a real tweeter - The Faital looks to be a fine driver.

 

[weltersys]

The horn will be of a spherical type.

Shaped like a globe ?

Many round horns (exponential, tractrix,etc.) simply cut off a portion of the throat to fit 1", 1.4" or 2", the horn length whether from the adapter "snout", or the horn throat will be about the same.
They all beam, unless conical or oblate spheroid.

 

[POOH]

Shaped like a globe ?

Many round horns (exponential, tractrix,etc.) simply cut off a portion of the throat to fit 1", 1.4" or 2", the horn length whether from the adapter "snout", or the horn throat will be about the same.
They all beam, unless conical or oblate spheroid.

Those beam too. Besides beeming can be good in a room

 

[LineSource]

A straight 1.4" throat exit from the compression driver will definitely generate the best sound when driving a mid-tweet range round horn like a JMLC.

Compression drivers with throat size adapters always show some discontinuities on the polar response plots.

Owner/Experts on both the JMLC and Lynn Olson threads recommend the JMLC 350 as the largest size JMLC mid-tweet to purchase for great high frequencies.

A spacer washer, like the cloth ring in your picture, is typically used to allow the diaphargm extra safe excursion travel. It is typically removed for low SPL home use to allow the best interfact to the horn.

 

[fpitas]

Those beam too. Besides beeming can be good in a room

Careful there. You'll get the constant directivity crowd in here with that kind of talk

 

[tinitus]

To address the confusion, see pic. It seems the driver is actually a HF146, but with an adapter expanding the throat to 2 inches.

interesting
I suspected the voice coil etc would be that same design
but a big surprice that it's 'just' a complete HF146 1.4" covered by the adapter

so I suspect the HF144 and HF204 are 'created' the same way

and only difference between the HF141 and HF201 is equally a simple insert with differnt exit hole

and HF140 = HF200

sorry, back to your waveguide/horn ... but thanks anyway, good to know this

 

[AndrewT]

Go from the driver to the horn direct, no added spacer.
I cannot see any advantage to adding an extra joint into the horn.

Try to find a horn that closely matches for both throat diameter AND throat exit angle.

 

[Defo]

It seems it will be best to use the drivers native 1,4" exit indeed. I will most likely try some simple horns made by myself first, and purchase a well made horn optimized for the driver at a later stage.

Thanks for the replies!

 

[tinitus]

I plan on using it "full range", that is 500hz and up. The horn will be of a spherical type.

It seems that going with the 1,4 inch throat is best, but that also means the horn will be longer, which could add more horn colorations, and theoretically will beam more with increasing frequency...

you might need very big horn

and that might have 2" throat

but will this driver really function well that low, without audible distortion

edit ... looks like some horns are all the same too, just with different adaptors, like the one you have on your driver

somehow I fail to see the difference
different exit/entry angles maybe ?

 

[Defo]

you might need very big horn

and that might have 2" throat

but will this driver really function well that low, without audible distortion

If you want directivity control and loading all the way down to 500 hz, then you would need to use a big horn.

But that doesn't mean you can't use a compression driver below horn/waveguide cutoff. It all depends on the application. For home listening levels, distortion levels are still neglectable below horn cutoff. Avantgarde Acoustic even does it with their midrange drivers, where the drivers are used well below the actual cutoff of the horn.

Note, I am by no means an expert. This is just the conclution I've reached from reading on this forum, and doing my own research.

 

[tinitus]

Defo, how is the angle on your driver adaptor, compared to the drivers own exit angle without the adaptor ?

I have been thinking about the same too

but having second thoughts ... 500hz ist still very low, and down where the driver is loosing output ?

 

[Defo]

Defo, how is the angle on your driver adaptor, compared to the drivers own exit angle without the adaptor ?

The angle seems identical. Looks like a pretty fast flare rate. I am still waiting for a response from Faital Pro about the actual numbers.

 

[tinitus]

Looks like a pretty fast flare rate.

shorter horn/waveguide maybe ? (but might not go low enough)

 

[Defo]

shorter horn/waveguide maybe ?

Yeah, thats one advantage. But given the rapid expansion rate, the horn/waveguide would almost certainly need to be custom made for the driver, which would be the disadvantage... But with that said, the driver sounds very good even now without(!) a horn.