I'm auditioning a couple of options for midranges in a horn-loaded system - a BG Neo8 and a set of Emilar compression drivers. I don't expect either one to reach 16KHz+ very gracefully... and I'm also not sure I need to hear much that high, but the thought exercise is grabbing me right now.
I understand horn driver directivity to be limited by throat size. 20KHz wavelength is 0.68 inches (17.3mm) so I guess smaller than that would be ideal.
B&C and LaVoce both have a couple of compression drivers with smaller than 1" diameter throats. They're not stated as being made to reach out past 18KHz though, and anyway I just read some complaints here about the phase plugs in these being very discontinuous and diffraction-prone.
The next best option seems like it might be the Dayton ND13FA: Dayton Audio ND13FA-4 - 0.5" Dome Tweeter. It's only down about 8dB at 45 degrees off axis at 20KHz. If it's built like the ND16FA, hopefully it has low distortion, good CSD and would take well to horn loading.
I have a 3D printer, and could maybe make a phase plug to fit it to a conical horn mouth with a smoothly transitioning wavefront. I'm not sure what to make of general advice that's been floating around here that horn-loaded domes don't take well to phase plugs though.
Any other options I should be looking at? Hoping to match up with 90x40 or so coverage from the midrange.
I understand horn driver directivity to be limited by throat size. 20KHz wavelength is 0.68 inches (17.3mm) so I guess smaller than that would be ideal.
B&C and LaVoce both have a couple of compression drivers with smaller than 1" diameter throats. They're not stated as being made to reach out past 18KHz though, and anyway I just read some complaints here about the phase plugs in these being very discontinuous and diffraction-prone.
The next best option seems like it might be the Dayton ND13FA: Dayton Audio ND13FA-4 - 0.5" Dome Tweeter. It's only down about 8dB at 45 degrees off axis at 20KHz. If it's built like the ND16FA, hopefully it has low distortion, good CSD and would take well to horn loading.
I have a 3D printer, and could maybe make a phase plug to fit it to a conical horn mouth with a smoothly transitioning wavefront. I'm not sure what to make of general advice that's been floating around here that horn-loaded domes don't take well to phase plugs though.
Any other options I should be looking at? Hoping to match up with 90x40 or so coverage from the midrange.
Just use a good B&C 1" driver and don;t worry so much about what is going on above 10 kHz. There will be sound, but almost anything this high up is going to have minimal directivity control, and waveguide will be best.
This is incorrect however. Its the waveguide design, especially at the throat as well as the phase plug that will limit the directivity control in this last octave. The throat size sets the limit of the HOMs and higher is better, so smaller throats are better, but the <1" drivers are not nearly as good as the 1" ones - like the DE500 which I use exclusively now.
Don't try and do a phase plug yourself unless you are very well versed in their design.
This is incorrect however. Its the waveguide design, especially at the throat as well as the phase plug that will limit the directivity control in this last octave. The throat size sets the limit of the HOMs and higher is better, so smaller throats are better, but the <1" drivers are not nearly as good as the 1" ones - like the DE500 which I use exclusively now.
Don't try and do a phase plug yourself unless you are very well versed in their design.
Last edited:
JBL uses two compression drivers and half-horns to widen the horizontal dispersion. It requires tiny compression drivers like the JBL 2408H.
Crossfired Waveguide Technology (CWT)
Crossfired Waveguide Technology (CWT)
Last edited:
The phase plug makes a big difference.
Take a look at this thread : For $200, can anything beat Pyle PH612 + JBL 2408H-1?
Here's a polar measurement that I did of the JBL 2408H-1. You can see that it maintains it's beamwidth up to about 18khz.
The 2408H-1 has a 1" throat. I have a pair of the new BMS headed my way this week, with a 0.68" throat. It will be interesting to see if they can match or exceed the JBL.
Obviously, this is a bit of a silly quest, I probably can't hear 18khz. But it's fun to see what's possible. IMHO, the reason that people like the sound of ribbon tweeters is largely because they offer high output above 15khz. Seems to add some "sparkle" to a speaker.
Take a look at this thread : For $200, can anything beat Pyle PH612 + JBL 2408H-1?
Here's a polar measurement that I did of the JBL 2408H-1. You can see that it maintains it's beamwidth up to about 18khz.
The 2408H-1 has a 1" throat. I have a pair of the new BMS headed my way this week, with a 0.68" throat. It will be interesting to see if they can match or exceed the JBL.
Obviously, this is a bit of a silly quest, I probably can't hear 18khz. But it's fun to see what's possible. IMHO, the reason that people like the sound of ribbon tweeters is largely because they offer high output above 15khz. Seems to add some "sparkle" to a speaker.
- Status
- Not open for further replies.