Page 3 of 3 FirstFirst 123
Results 31 to 38 of 38

Thread: 2470 Franken drivers

  1. #31
    Senior Member
    Join Date
    Apr 2003
    Location
    Australia
    Posts
    7,942
    http://www.lansingheritage.org/image...omp/page10.jpg

    The Selenium look more like the consumer HL92

    That longer than the HL91/2307

    We look forward to your progress on horn evaluations

    I will post the voltage driver of the EQ network discussed previously later in
    The week

  2. #32
    Member
    Join Date
    Mar 2012
    Location
    Sutter Creek, CA
    Posts
    57
    Cutting the plates for a 2308 on my CNC laser would be pretty easy. I just have to find a .bmp file or drawing of one plate and correctly size it. Its basically a rectangle, but the V notch specs are the unknown. Tap Plastics can provide the ABS sheet material. Or I can use a cheap 1/8" plywood for experimenting.

    It will take a few days to get this all together.

    Will post more when I make some progress.

    HL92 is close, but not exact. 2312 maybe?

  3. #33

  4. #34
    Senior Member ivica's Avatar
    Join Date
    Jan 2008
    Location
    serbia
    Posts
    1,703
    Quote Originally Posted by GoldcountryJim View Post
    Cutting the plates for a 2308 on my CNC laser would be pretty easy. I just have to find a .bmp file or drawing of one plate and correctly size it. Its basically a rectangle, but the V notch specs are the unknown. Tap Plastics can provide the ABS sheet material. Or I can use a cheap 1/8" plywood for experimenting.

    It will take a few days to get this all together.

    Will post more when I make some progress.

    HL92 is close, but not exact. 2312 maybe?
    Hi Jim,

    If you do like formulas, as I have sent you a link, you can redraw from the
    http://www.audioheritage.org/vbullet...l=1#post186755

    regards
    ivica

  5. #35
    Member
    Join Date
    Mar 2012
    Location
    Sutter Creek, CA
    Posts
    57
    The patterns for the plates are really helpful. The plan is to cut prototypes this weekend.

    I read somewhere on the forum that the plates have to be spaced less than 1/2 the wavelength (of the highest frequency?) apart to work properly. It seems the actual number of plates is less important and just needs to cover the horn opening.

    Does anyone have information on this?

    Have a bunch of parts ordered (horns, adapters, diaphragms) and just waiting for them.

  6. #36
    Senior Member
    Join Date
    Apr 2003
    Location
    GTA, Ont.
    Posts
    5,109






  7. #37
    Member
    Join Date
    Mar 2012
    Location
    Sutter Creek, CA
    Posts
    57
    Earl,

    That's really good information! I had a moment of enlightenment about the "potato masher" horns in there. It starts to make sense, but also spawns so many questions like: Can you shape the waves differently to improve the stereo image? Why did JBL choose a V notch rather than a curve on the 2308? Could I filter particular frequencies by changing the lense plate (2308 style) density?

    This is going to be more interesting than I expected. I was thinking of the 2308 as more of a directional device.

    I think my question of plate spacing remains. I'll keep digging.

  8. #38
    Member
    Join Date
    Mar 2012
    Location
    Sutter Creek, CA
    Posts
    57
    Found the information! It was page 3 of the same paper. Should be a fun weekend!

    http://www.lansingheritage.org/image...ens/page03.jpg

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •