2404H horns with 2414H-1 drivers work?

[CowFish]

Hello,
Noob questions here and looking for some input.
I'm building a pair of custom 3 ways based on the 2214H 12" woofer in a L100t3 enclosure. I don't much care for the 104H-x mids or 035ti tweets, hence going custom, but I do LOVE that 12" woofer in 3 ways.
The mids are already sorted.

So for the hf, I'd really like to use the 2414H-1 compression driver as I've come to love it based on my Studio 580 & 590 speakers. This is that same 1" driver that comes in many of the JBL EON series pa speakers btw.
Will it screw into a 2404H baby cheek horn and work well from about 2.5k and up?
The mid I chose is very flexible as far as crossover point, so that's not the issue, more so if that driver would work with that horn to cover the hf portion of this home stereo 3 way tower.

Thank you so much for any input, and I will be documenting this build here with lots of pics!
Best regards

[grumpy]

Not with any kind of predictable success.
Would sound come out the hole? Sure.

Do you have both the 2404 horn (removed from the ring-radiator driver/phaseplug assembly) and the 2414 in hand?
I think it would answer your question. There are (much) more appropriate horns to hang your 2414 on.

[CowFish]

Thank you for the input, I did not know that.
I do not own any 2404s, and because they're expensive, I wanted to ask here first about using them for this application.
What are some (inexpensive-ish) horns that would be more appropriate for the 2414H-1? Anything from parts-express?
I know pretty much nothing about horns, except that I really like the bi-radial ones on the Studio 580s.
Thanks!

[grumpy]

could look at eminence apt-200s horn from PE or perhaps something from JBL’s JRX series that fits the 1 3/8” 18tpi threads of the 2414 type driver (very different horns, will depend on your use and custom crossover skills). I have nothing pre-made/tested for you. Others here might.

Thank you for the input, I did not know that.
I do not own any 2404s, and because they're expensive, I wanted to ask here first about using them for this application.
What are some (inexpensive-ish) horns that would be more appropriate for the 2414H-1? Anything from parts-express?
I know pretty much nothing about horns, except that I really like the bi-radial ones on the Studio 580s.
Thanks!

[pos]

The small waveguide used in the AC16 is a good candidate, and you could even use the passive network of the AC16 with the 2414.
I use it with a 2407 and the result is impressive: directivity is very well controlled in the 2.5kHz-20kHz range.
Here it is: https://reconingspeakers.com/product...ide-horn-lens/

[CowFish]

could look at eminence apt-200s horn from PE or perhaps something from JBL’s JRX series that fits the 1 3/8” 18tpi threads of the 2414 type driver (very different horns, will depend on your use and custom crossover skills). I have nothing pre-made/tested for you. Others here might.

The apt 200s reminds me of the baby cheeks horn and it's inexpensive, so I'm leaning towards that for sure.
The AC16 is always a feasible back up.
I've gotten pretty good with building passive crossovers, and also have an Ashly XR-1001 electronic crossover at hand.
Thanks so much for the advice.

[Horn Fanatic]

[QUOTE=CowFish;416729]Hello,

"Will it screw into a 2404H baby cheek horn and work well from about 2.5k and up?"

Greetings -

The 2414 compression driver has a 1 inch throat exit.

The throat for the 2404 bi-radial horn has a 1/2 inch throat entry.

Even if you could adapt the 2414 driver to the 2404 horn, the 1 inch to 1/2 inch adapter that would be required will cause a restriction which would technically behave as an acoustical low-pass filter, in a similar manner as a choke on a woofer results in an electrical low-pass filter. In electrical terms you have an inductor. In acoustical terms you have an acoustical mass. They both use the same symbol and calculations, the resulting value in Henry. As far as acoustical compliance; calculations between an acoustical circuit are treated the same as with an electrical circuit, the resulting value in Farad. Such an arrangement will in fact, reduce high frequency. The frequency where the attenuation will occur can be calculated, providing the volume between the 1 inch throat exit of the 2414, and 1/2 inch throat entry of the 2404 horn is known.

Picture using the JBL 2330 throat adapter from a 2 inch exit 2440 to an ALTEC 1.4 inch throat horn.

Another example would be the JBL 4530 folded horn enclosure. The diaphragm area of the 15 inch speaker is greater than the throat area of the bass horn by an approximate factor of 2:1. The volume of the speaker chamber, and the area difference between the speaker and throat, combine to serve as an acoustical low-pass filter. The very function of an acoustical low-pass filter is to attenuate high frequency. The diaphragm area, the throat area, and chamber volume are interrelated. Change one parameter, and you will change the attenuation frequency.

With respect to a Helmholtz resonator; take a coke bottle for example. Blowing across the neck produces a resonant frequency because air is trying to get into the bottle at the same time air is trying to get out. Change the volume of the bottle, the frequency changes. Change the neck length, the frequency changes. Change the diameter of the neck, the frequency changes.

If you read the literature about the JBL 4520 & 4530 enclosures, it states that the speaker acts as a direct radiator above 150 cycles. Frankly, I'm not buying it. I believe it's more like approximately 300 cycles. Perhaps if the chamber volume was doubled or so, the frequency would drop. The problem with that scenario, is if you change the volume without changing the throat area to compensate, the acoustical reactance of the chamber acoustical compliance, and acoustical mass reactance of the throat area would cause an impedance mismatch, which would preclude any chance of reactance annulling. The acoustical reactance of the diaphragm, the chamber volume acoustical reactance, and throat area acoustical mass reactance as an acoustical circuit, must be at unity. Increase the chamber volume, increase the throat area. Or decrease in kind.

The same principle holds true for your above mentioned scenario.

H.F.

P.S. The throat adapter between the JBL ring radiator motor, and the 2404 bi-radial horn by itself would function as an acoustical low-pass filter, if it weren't for the phase plug. In case you were wondering.

[CowFish]

Very interesting, thank you for that detailed response and info.
I guess at this pint my two options for integrating a baby cheek into this 3 way hifi tower are: 2404 with stock drivers, or 2414H-1 drivers with apt-200s horns. The latter option being significantly less expensive.
Thank you all for chiming in. I will get started with this build within a few days and document it in a dedicated thread here.
Best regards

[Horn Fanatic]

Very interesting, thank you for that detailed response and info.
I guess at this pint my two options for integrating a baby cheek into this 3 way hifi tower are: 2404 with stock drivers, or 2414H-1 drivers with apt-200s horns. The latter option being significantly less expensive.
Thank you all for chiming in. I will get started with this build within a few days and document it in a dedicated thread here.
Best regards

If you plan on using the APT-200 horn, consider this.

As a rule of thumb, the crossover frequency that should be used is typically one octave above the low frequency cut-off of the horn. Or, the wavelength of the crossover frequency should be half that of the horn circumference in order to inhibit or eliminate any distortion caused by having the wavelength of the crossover frequency equal to, or greater than the circumference of the horn. The later scenario will cause a portion of the out going wave to reverse direction back to the source, and in turn collide with the oncoming wave. The condition is called a standing wave, which is an undesirable resonance. It's the same reason microwaves do not penetrate the glass in a microwave oven. The wavelength of the microwave frequency is greater than the circumference of the individual holes in the screen. The energy bounces back into the oven. Have you ever wondered why you can watch your food cook in a microwave oven, and not get cooked yourself?

A simple experiment;

Take a paper towel tube, place it to your mouth, then do the 'oooo' thing over a wide frequency range. At one point you will feel the tube resonate. That is because you reached a frequency which has a wavelength greater than the circumference of the tube, and have induced a standing wave.

For example; An ALTEC Lansing 811 horn is typicaly crossed over at approximately 800 Hz. The 811 horn flare rate is approximately that of a 400 cycle horn. The same holds true for the 511 horn, which is typically crossed over at 500 Hz. The flare rate for the 511 would approximately be that for a 250 cycle horn.

Another example; the circumference of a JBL 075 ring radiator is approximately 9.8 inches. Divide the velocity of sound by the circumference and you get 1.3K plus change. The cross over frequencies over the years used on the 075 have been between 2.4K & 2.6K.

The 077 has yet a smaller mouth area, and JBL saw fit to use the N7000 on that device. The mouth area for the 077 is approximately 1.5625 square inches, with a circumference of approximately 4.4 inches. The low frequency cut-off based on the 077 mouth circumference is approximately 3K.

The math will bear this out.

Putting a reduced mouth area horn on a compression driver will not increase it's frequency response to that of a ring radiator tweeter. Doing so would actually loose the capability to cleanly reproduce the lower frequencies for which it was designed.

Good luck,

HF

[CowFish]

Thank you for that information. It all makes sense.
Luckily, the mid I'm using is a full ranger and thus very flexible up top (and at the bottom) to crossover.
What would be a good crossover frequency starting point for the APT-200 horn loaded with a 2414H-1 driver?
For the 12" woofer low pass, I was just going to copy the JBL L100t3 crossover.

Thanks!

If you plan on using the APT-200 horn, consider this.

As a rule of thumb, the crossover frequency that should be used is typically one octave above the low frequency cut-off of the horn. Or, the wavelength of the crossover frequency should be half that of the horn circumference in order to inhibit or eliminate any distortion caused by having the wavelength of the crossover frequency equal to, or greater than the circumference of the horn. The later scenario will cause a portion of the out going wave to reverse direction back to the source, and in turn collide with the oncoming wave. The condition is called a standing wave, which is an undesirable resonance. It's the same reason microwaves do not penetrate the glass in a microwave oven. The wavelength of the microwave frequency is greater than the circumference of the individual holes in the screen. The energy bounces back into the oven. Have you ever wondered why you can watch your food cook in a microwave oven, and not get cooked yourself?

A simple experiment;

Take a paper towel tube, place it to your mouth, then do the 'oooo' thing over a wide frequency range. At one point you will feel the tube resonate. That is because you reached a frequency which has a wavelength greater than the circumference of the tube, and have induced a standing wave.

For example; An ALTEC Lansing 811 horn is typicaly crossed over at approximately 800 Hz. The 811 horn flare rate is approximately that of a 400 cycle horn. The same holds true for the 511 horn, which is typically crossed over at 500 Hz. The flare rate for the 511 would approximately be that for a 250 cycle horn.

Another example; the circumference of a JBL 075 ring radiator is approximately 9.8 inches. Divide the velocity of sound by the circumference and you get 1.3K plus change. The cross over frequencies over the years used on the 075 have been between 2.4K & 2.6K.

The 077 has yet a smaller mouth area, and JBL saw fit to use the N7000 on that device. The mouth area for the 077 is approximately 1.5625 square inches, with a circumference of approximately 4.4 inches. The low frequency cut-off based on the 077 mouth circumference is approximately 3K.

The math will bear this out.

Putting a reduced mouth area horn on a compression driver will not increase it's frequency response to that of a ring radiator tweeter. Doing so would actually loose the capability to cleanly reproduce the lower frequencies for which it was designed.

Good luck,

HF

[Horn Fanatic]

"What would be a good crossover frequency starting point for the APT-200 horn loaded with a 2414H-1 driver?"

Thanks!

Based on the horn mouth dimensions, I think 1.5K would be safe bet. However, the 2414 data sheet suggest a 2.1K crossover frequency. The 2414 published highest frequency response is listed as 20K. It probably begins to tank before that.

H.F.

P.S. It's just my opinion, but is the 2414 actually suited for reproducing music for a consumer audio system? That it is used in an EON speaker doesn't bode well for use in a Hi-Fi system. Titanium diaphragm I presume?

[gdmoore28]

If you plan on using the APT-200 horn, consider this.

As a rule of thumb, the crossover frequency that should be used is typically one octave above the low frequency cut-off of the horn. Or, the wavelength of the crossover frequency should be half that of the horn circumference in order to inhibit or eliminate any distortion caused by having the wavelength of the crossover frequency equal to, or greater than the circumference of the horn. The later scenario will cause a portion of the out going wave to reverse direction back to the source, and in turn collide with the oncoming wave. The condition is called a standing wave, which is an undesirable resonance. It's the same reason microwaves do not penetrate the glass in a microwave oven. The wavelength of the microwave frequency is greater than the circumference of the individual holes in the screen. The energy bounces back into the oven. Have you ever wondered why you can watch your food cook in a microwave oven, and not get cooked yourself?

A simple experiment;

Take a paper towel tube, place it to your mouth, then do the 'oooo' thing over a wide frequency range. At one point you will feel the tube resonate. That is because you reached a frequency which has a wavelength greater than the circumference of the tube, and have induced a standing wave.

For example; An ALTEC Lansing 811 horn is typicaly crossed over at approximately 800 Hz. The 811 horn flare rate is approximately that of a 400 cycle horn. The same holds true for the 511 horn, which is typically crossed over at 500 Hz. The flare rate for the 511 would approximately be that for a 250 cycle horn.

Another example; the circumference of a JBL 075 ring radiator is approximately 9.8 inches. Divide the velocity of sound by the circumference and you get 1.3K plus change. The cross over frequencies over the years used on the 075 have been between 2.4K & 2.6K.

The 077 has yet a smaller mouth area, and JBL saw fit to use the N7000 on that device. The mouth area for the 077 is approximately 1.5625 square inches, with a circumference of approximately 4.4 inches. The low frequency cut-off based on the 077 mouth circumference is approximately 3K.

The math will bear this out.

Putting a reduced mouth area horn on a compression driver will not increase it's frequency response to that of a ring radiator tweeter. Doing so would actually loose the capability to cleanly reproduce the lower frequencies for which it was designed.

Good luck,

HF

HF, that is one of the clearest and most concise explanations I've read about horn mouth area, resonant frequencies, crossover frequencies and other technicalities. I'm bookmarking this post for future reference. Thanks so much, my friend!

GeeDeeEmm

[CowFish]

Based on the horn mouth dimensions, I think 1.5K would be safe bet. However, the 2414 data sheet suggest a 2.1K crossover frequency. The 2414 published highest frequency response is listed as 20K. It probably begins to tank before that.

H.F.

P.S. It's just my opinion, but is the 2414 actually suited for reproducing music for a consumer audio system? That it is used in an EON speaker doesn't bode well for use in a Hi-Fi system. Titanium diaphragm I presume?

Yes the 2414H-1 (polymer diaphragm) sounds absolutely top notch in my Studio 580 & 590 towers designed by Greg Timbers. Some of the best speakers I've ever heard if not the best. My upstream electronics are no slouches either and my room is somewhat treated though not perfect, so that doesn't hurt. I've had many, many speakers come through my listening room and auditioned countless more in friends' listening rooms, and I gotta say these are endgame speakers for me.

These new project towers I'm building for a friend, using the 2214H 12" woofers, some 5" full rangers, and now most likely the APT-200S horns loaded with 2414H-1 compression drivers. I'll design the passive crossovers, improve the L100t3 cabs (bracing and mirror imaging) and veneer in fresh cherry and deliver them when I think they're well dialed in. Should be a fun project.
I will document the build on here with lots of pics.
The reason for the custom mids and hf (over stock L100t3) is that I don't think the 104H-2 mids and 035ti tweeters are that great.