So these are very nice drivers but why do you want to use them? the special property of the TD-4001 is the large format Be diaphragm which allows the driver to cover a wide frequency range of 600 - 20,000Hz without dome breakup. If you use it with a ribbon tweeter you could use a far lower cost Ti diaphragm driver without issue. The TAD is also more expensive than a brand new 18 sound Be driver or coaxial compression driver.
Personally I would simplify the design to 3 way and build something like this:
Suggested Design: 15SW100 / DCX464 / ME464 Point Source - YouTube
the response off axis will be much improved due to the acoustic closeness of the sources.
Lack of issue with excess group delay and Decay was where I was heading....If you are crossing, high enough, to use a 1st order xo then I'd think you moved the XO point well beyond "high enough" to avoid the distortions brought by the horn cutoff area. In my opinion the Waveguide has non of these issues....but I get the feeling it has its own challenges...something about a worse transient response...I've never looked into it, so I do not know.
Now with Weltersys, AllenB, et al in attendance and we'd really have some fireworks. Just kidding. But seriously, most them have been strongly insistent that I use JMLC AH425 horns to build my two-way system. How much distortion would that horn create than this one? https://josephcrowe.com/blogs/news/circular-horn-no-1689
But if I didn't go with that horn, can some recommend a better constant directivity horn than the TH-4001?
https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg for my midwoofers?
https://josephcrowe.com/blogs/news/altec-416-8b-in-100l-sealed
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The 1" driver/throat horn would have more distortion than your 3" BE on your AH 425.https://josephcrowe.com/blogs/news/circular-horn-no-1689
The TH-4001 is not a constant directivity horn, it's vertical directivity varies with frequency.
If you're referring to the Yamaha JA6681B, isn't the throat diameter 35mm ~ 1.4", like the Radian 745Be?
https://audio-database.com/YAMAHA/unit/ja-6681.html
That's what I thought Docali once said too. But check his reply about same at post 15698.
https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-785#
As for most devices you have to decide about compromises. TH4001 has almost constat directivity control in the major hrz listening plane. The vertical is less important. But it is still fairly good for this more, although much more narrow. But do you hear with your head on floor or ceiling level?
Ha! No, I wasn't over concerned with the vertical directivity for that obvious reason.
I may have an opportunity to use one of these 2” versions, rather than my 1.4” version, in the TH-4001 or if another 2" CD horn proves to be recommended for my room.
https://www.usspeaker.com/radian 760Bepb-1.htm
https://www.usspeaker.com/radian 760neoBepb-1.htm
https://www.usspeaker.com/radian 850Bepb-1.htm
https://www.usspeaker.com/radian 950Bepb-1.htm
Presumably, the 760 would be ideal.
Ferrite or Neodymium?
From HERE!
Note1, at the time the thread was created, Pierre thought he owned a used A290 when he made and posted these measurements (later, it turned out that he had bought a TH4001 ).
- Hence the mis-labelling seen in the following picture.
Note2, A custom throat adapter significantly smoothed out the response below 1K.
🙂
Note1, at the time the thread was created, Pierre thought he owned a used A290 when he made and posted these measurements (later, it turned out that he had bought a TH4001 ).
- Hence the mis-labelling seen in the following picture.
Note2, A custom throat adapter significantly smoothed out the response below 1K.
🙂
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Presumably, this is an accurate polar though driver was not specified.
https://audiohorn.net/img/bi-radial/TAD-TH4001-polar.jpg