Baby Butt Cheek tweeter Eminence EM:200S frequency cut off point

[Phenoholic Anonymus]

I have some questions about this tweeter / horn type.

1. Can someone point me out where to buy this horn without the APT tweeter attached to it in Europe. I cannot find this horn without the tweeter attached to it. I only care for the flare.

2. What would be the frequency cut off for this hornflare type. I intend to use it 2.5 kHz and above. It would be usefull if i have someway to determine the fc for this tweeter type. As an alternative for the EM 200S flare, i could get this smaller one. 88 x 88 mm (and replace the driver). But i have some doubt about size and Fc of the Dibeise F24 flare. Please notice both Baby But Cheek tweeter's do not have the difraction slot as seen in the original JBL 2404H.

 

[flg]

I am also interested in this Butt-Cheek...
Eminance has 2 pages. 1 for car audio and 1 for the horn, I believe.
Edit: the link you gave is without the driver! (Butt they K%&A^& laying down, by the pic)
I've seen 1600 and 2500 as the Fclow. But, the data is with their driver??? I'm interested in using maybe a DE-250??? At Fc=2250Hz maybe (1.6-2.750kHz)
There are a couple others that might be considered comparable but 🙄 Butt higher Fc.
The Beyma maybe...
Thanks for posting, I was about ready to start this thread myself 😀

 

[Phenoholic Anonymus]

I am particulary interested in this one because of the 90 x 90 degree radiation. A good fit for the midhorn i plan to use. The denovo DNA 150 could be a good match. (slighty OT link to other babycheek with roughly the same dimensions + neodymium DNA 150 style tweeter + measurement).

Parts express states 1.300 as lowest recommended crossover point. I guestimate the mouth to be about 150 cm2. 1.3 kHz is fairly optimistic...

I have heard the APT 50 in several designs. It will never offend someone, and it will never make someone pay particular attention to it, it can play loud, but it does not make my clock tick.

 

[weltersys]

1. Can someone point me out where to buy this horn without the APT tweeter attached to it in Europe.
2. What would be the frequency cut off for this hornflare type. I intend to use it 2.5 kHz and above. It would be usefull if i have someway to determine the fc for this tweeter type. As an alternative for the EM 200S flare, i could get this smaller one. 88 x 88 mm (and replace the driver). But i have some doubt about size and Fc of the Dibeise F24 flare.
3)Please notice both Baby But Cheek tweeter's do not have the difraction slot as seen in the original JBL 2404H.

1) Can't help you.
2) The smaller bi-radial horn (with a different driver) does not start dropping off until around 800 Hz. Using the APT driver I'd expect response to be falling steeply by at best 1600 Hz, the APT Fs is 2100 Hz.
I'd guess the APT LF response to be between the two shown below, the "APT Raw" is an APT80 with an additional 3/4" 90 degree horn flare, the "2x6T" is a 90 x 40 conical horn about 13.5" wide x 5" tall.
The APT HF response is a crap shoot, each of the ten I own have quite different response.
3)The lack of the diffraction slot will reduce VHF dispersion and output compared to the 2404.

Art

 

[Phenoholic Anonymus]

Thanks Art! The bigger Eminence Buttcheeck flare should be just about usable 2.5 kHz and up i guestimate.

 

[weltersys]

Thanks Art! The bigger Eminence Buttcheeck flare should be just about usable 2.5 kHz and up i guestimate.

If you put it on a large baffle it probably would be no more than 180 degree dispersion at 2.5kHz and below 😉.

 

[Phenoholic Anonymus]

So no hornloading or pattern control below 2.5 kHz?

 

[Elias]

Beyma CP25 is similar size. Available in Europe.

 

[Phenoholic Anonymus]

Thanks Elias,

The good reviews for the CP25 (and it's wide dispersion) got me interested in this type of horn. The 100 x 60 directivity of the CP25 is to wide for my needs. Besides i like the idea of the TPI thread so i can switch drivers. There are some budget CD drivers i am curious about, the DNA 150 style neodymium beeing one of the them, Sica CD 83.26 /380 beeing another. There is little known about these drivers, but what can be found is enough to spike my curiosity.

It's strange nobody is familiar with this hornflare -sans- APT 80 tweeter. Maybe i should have posted this in Pro Audio. Does anybody know another Buttcheek 90 degrees wide dispersion TPI flare for 2 kHz and up? Available in Europe.

 

[weltersys]

So no hornloading or pattern control below 2.5 kHz?

Pattern control does not turn off instantly, but below around one wavelength of the smallest mouth dimension the pattern will start to widen as the waves diffract around the mouth.

You wrote "the 100 x 60 directivity of the CP25 is to wide for my needs".

Without polar response charts of the different horns it is impossible to compare their dispersion.
The difference between -6 dB at 90 and 100 degrees, even if they both were constant directivity (they aren't) would be very little.

 

[Elias]

Does anybody know another Buttcheek 90 degrees wide dispersion TPI flare for 2 kHz and up? Available in Europe.

Some older models of P Audio were like that, too. They still available in some online shops.

 

[Phenoholic Anonymus]

Pattern control does not turn off instantly, but below around one wavelength of the smallest mouth dimension the pattern will start to widen as the waves diffract around the mouth.

Thanks, it was this simple guideline i was looking for . I am new to horn's, this helps me make a crude judgement about range when comparing horns. So 90 or 100 degrees is not such a big difference, good to know!

Thanks Elias for the P.audio tip. These are quite big i believe (230 x 230), it's a shame we cannot buy this simple piece of Eminence hornflare ABS without the driver in the EU. Makes you wonder about 3D printing, afaik that's 0.40 euro / cm3 + some initiatal setup costs +- 5,- 🙂

 

[badman]

Look for Selenium HM17-25, which is similar if not identical.

 

[Phenoholic Anonymus]

Thanks, the Selenium is available in the EU and not overpriced. Maybe time to ease up on the 90 degrees a little.

 

[weltersys]

Maybe time to ease up on the 90 degrees a little.

If you already have the APT 80, why not make an extension with a round over.
The extension can easily be made to whatever size you would like using a 45 degree router bit using a hole jig, just make each layer larger, and when as big as you want hand file the exit round and finish sand.

Just increasing the depth by 3/4" makes the horn quite a bit larger, decreasing the pattern control frequency, and reducing edge diffraction.

Again, the difference between a nominal 80 x 80 and 90 x 90 is not much, and the APT driver has relatively ragged frequency response on any horn.

 

[Phenoholic Anonymus]

An externally hosted image should be here but it was not working when we last tested it.

Something like this? I planned to make roundover's around the horn and play with some felt in the mouth. I had not yet combined the idea of a roundover with making a horn bigger / extending the range where wave's roll back. Thanks, another piece clicks in place. The buttcheeck flare shown above would also need a roundover at the top and the bottom ( in the picture, where the front plate is flat).

Did anybody try 45 degree roundovers yet on hornflares? The results on baffle roundovers for tweeters would suggest that would work.

An externally hosted image should be here but it was not working when we last tested it.

 

[weltersys]

Something like this?
Did anybody try 45 degree roundovers yet on hornflares? The results on baffle roundovers for tweeters would suggest that would work.

The 45 degree horn extension for the APT 80 benefits from a radius (roundover) at the mouth.
The (crappy)diagram below might make what I was suggesting more clear, the white portion is the original APT 80 horn mouth, three layers of extensions above.
Although I only added 3/4" depth and rounded the mouth, the difference was quite audibly smoother( and pattern control to a lower frequency) compared to the APT 80 raw horn.

Rounding over the hard edges of any horn, especially little horns, will reduce edge diffraction.

Some of the LaCleach horns have huge roundovers.

 

[Phenoholic Anonymus]

Thanks for the drawing! 50% original / 50% add on diy mdf horn 🙂 I noticed the JMLC horns. And i have followed Mr. Bateman's adventures with roundovers. Interesting stuff.

 

[weltersys]

Thanks for the drawing! 50% original / 50% add on diy mdf horn 🙂

I seldom use MDF, but the addition of the extension and roundover really do help.

Here is the response of a 2x8" monitor with an APT with a 3/4" extension and roundover, the acoustic crossover is around 3500 Hz, but is nearly undetectable in the phase and frequency response in that region, though the upper APT dips and peaks are 🙄.

The entire passive crossover had a low parts count, only 2 coils, 2 capacitors, 2 resistors, and about 30 hours of substituting parts to get a good response.

 

[Kwikas]

Phenoholic,

Any update on this? Just interested. I am considering using these wave guides for my surrounds (above a JBL 2123h) but would like to hear from some one who has had real time experience with using them.

There seems to be limited info or feedback from custom builders who've tried the EM200S.