3 way MEH with a planar tweeter (GRS PT2522 tweeter, FaitalPro 3FE22 mids)

Member
Joined 2008
Paid Member
As the test horn (https://www.diyaudio.com/community/threads/3-way-meh-with-1-4-cd-3d-print-and-cnc.383396/) progresses forward, I am slowly starting to think about the successor of it.

Here is some first Hornresp simulation, using 4x 3FE22 as mids and 2x Fane Sovereign Pro 12-300, sealed with a little EQ and a basic crossover:
1687344964763.png


The Hornresp records are attached. Depending on how the measurements on the first prototype will finish, this one will be built using 12 mm chipboard, since the final one will be most probably from 12 mm birch plywood.

It is meant to be 85 x 65 degrees, 40 cm length, mouth dimensions ca 78 x 57 cm, with the option of external secondary flare. I am still not decided on the bass drivers, but the Fanes look pretty fine. I was also thinking about using car audio subwoofer drivers for lower SPL and lower LF cutoff.
 

Attachments

  • Syn2Mids.txt
    2.7 KB · Views: 76
  • Syn2Bass.txt
    2.7 KB · Views: 47
  • Syn2Proto.txt
    2.7 KB · Views: 50
  • Like
Reactions: 3 users
Member
Joined 2008
Paid Member
I really like the (open baffle) bass of the single 18" in my first test horn. I also had some good experience with SLOB 2x12 (I do not care for the slot, but I dig the force cancelling), therefore I am considering to use a folded 2x18 SLOB of matching size for the lowest band. Or two PPD style OBs.
 
  • Like
Reactions: 1 user
Member
Joined 2008
Paid Member
Improved (adjustable) fixture using 3D printed sliders and one hand clamps. This time I played around with the adjustments for a while and the result seems to be more square than the first one. Still not perfect, but good enough.
 

Attachments

  • IMG_7294.jpeg
    IMG_7294.jpeg
    593.5 KB · Views: 108
  • IMG_7296.jpeg
    IMG_7296.jpeg
    433 KB · Views: 106
  • IMG_7292.jpeg
    IMG_7292.jpeg
    341.3 KB · Views: 110
  • IMG_7291.jpeg
    IMG_7291.jpeg
    614.6 KB · Views: 94
  • Like
Reactions: 2 users
Not unlike a Chinese meal - it’s all prep. and very little cooking-time. ;) (..well, a stir-fry meal.)

CAD time + a bit of machine setup and the machines do the rest. (..though you typically have to check-in on the CNC and particularly the 3D print.) Of course like the meal there is also time spent on “cleanup”/quality-control.
 
  • Like
Reactions: 1 user
Member
Joined 2008
Paid Member
To make it a bit stronger and to practice painting, I used leftover paint from another project. Not exactly a fan of this green, but it looks better than the yellow I used on the previous model. One or two more layers and it will be fine.
 

Attachments

  • IMG_7302.jpeg
    IMG_7302.jpeg
    433.7 KB · Views: 88
  • Like
Reactions: 1 users
Member
Joined 2008
Paid Member
In the other thread, someone suggested to use two (or even three) long planars. I think this horn will be the next prototype to compare with the green one:
1687988123815.png

1687988161875.png

This was just a quick modification of the OpenSCAD file, it will most probably use a round central entry port for the 12" woofers. It takes only one "project board" of 16 mm chipboard (1400 * 1050 mm), which is dirt cheap. I need to solve the mounting of the large Heil AMT for the third prototype and then decide, which one is actually the best:) It will be a touch choice, since I am now really happy with the Trynity prototype with the small PT2522.
 
  • Like
Reactions: 1 users
Member
Joined 2008
Paid Member
Reducing the old AMT-1 adapter design to only square box insert seems to be an option. This will be printed either as two halves (one shown in the picture) or as one piece - that will be decided after some test prints. If this proves to be a viable mounting option, the third prototype will definitely be built as well. Most probably as two way, but that will depend on how the first green prototype will measure and how close will I be able to fit the 12" woofers.

1688078813005.png
 
Member
Joined 2008
Paid Member
Test fitting was successful. The front of the printed parts will be glued and screwed to the horn flange. If I find out the mids are necessary, it will be possible to fit them on the printed part again.
 

Attachments

  • IMG_7367.jpeg
    IMG_7367.jpeg
    438.4 KB · Views: 112
  • Like
Reactions: 3 users