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JE Labs Open Baffle redux



G. A. Briggs
Wharfedale SFB3
Stereo Sound "Tube Kingdom" 1996 Volume 3
DIY/'cheap' version inspired by Stereo Sound
featured
in Sound Practices 17 "JE Homebrewer"
JEL OB for Altec 755 built from
3/4" Birch plywood ca. 1997
Built using Tanguile 'tongue in groove'
 flooring planks for an Altec 605B 

November 2008 Hi-Fi Show

Mondrian 2011 edition
for a 12" driver 

Have fun and happy listening!

Comments

  1. Hi.

    Apologies if this appears twice.
    I want to try this open baffle for my 12" Phillips full range.
    It is the AD12100 M8.
    I currently also have an unknown 8" fullrange , all I can see is made in Taiwan and the letters "PF - 8012 HRW CE7" , but it came with the Phillips and they seem to blend / match nice in simple parallel connection without crossover.
    I'd like to mount them both to the same Baffle, so the question is if I do still keep to the 900 x 800 Demsions for the main baffle front panels.

    Tx a mill for any advise.

    Regards.
    Julian

    ReplyDelete
    Replies
    1. The baffle dimensions should remain the same regardless of number of drivers used. See the Wharfedale SFB3 picture above for multi driver use.

      Happy Listening!

      JE

      Delete
    2. Hi JE.

      Tx a mill for everything.
      I eventually decided to go with a sigle driver only choosing the philips AD12100.
      Here, is a link to a thread on our local forum to show the build and some pics and tips on more questions I encountered etc.

      http://www.avforums.co.za/index.php/topic,23949.0.html

      All I can say is that this is the most realistic musical system I have ever owned and I love the way it plays music with my electro harmonics 300b mono push pull.

      I do have another question(pardon my ignorance, I do not have any tech backgrounds).
      looking at the free field response graph, will I go lower in freq if I extend my baffle.
      I am trying to think what will happen if I change for example the triangular shape of the side wings each to be 0 inches at the top and all the way to say 65 inches at the bottom.... any theoretical answer will be appreciated.
      Kind regards
      Julian.

      Delete
    3. I've been busy lately and have not been checking the blog regularly. Since I have not tried any of your proposed revisions, I am hesitant to give advice. I am a musician who dabbles with DIY audio ideas during my spare time. When an experiment results in a musically satisfying experience I upload it to inspire others to venture into DIY. Hope this helps and good luck!

      JE

      Delete
  2. Hi

    Just to let you know, I tried extending the legs as described above, but back to the original design on this page. I found placement was more usefull then fiddling with this design.
    Tx a mill, I now sold my B&W speakers in favour of this open baffle and the push pull 300b mono amps... really happy...
    Now I will commit to this design and as soon as funds are available, I want to redo the baffle with a hardwood, rose or something similar and make it a bit heavier... Will post when that part is done...
    tx again.

    ReplyDelete
  3. Thought I would drop by and make a few comments about my take on the "JE Labs style" OB. First, thanks to Joseph for providing this to those of us who would not have otherwise known about this simple, yet great DIY project.

    I built mine using 18mm Baltic Birch plywood. Instead of the 5" or 6" top shelf I built them using a "full width" shelf (25 or 26 inches long). I also nailed a 5" or 6" piece between the uprights. This created much needed bass extension. I've tried the OBs with only a couple of configurations: Hemp 8" full range drivers, Altec 408C co-axials, and Oxford J10, 12" organ full rangers, augmented with a salvaged crossover from an old set of Wharfdale Denton IIs, and a coaxially mounted Seas tweeter (salvaged from an old set of Mission loudspeakers). The later is the best combination thus far. I've driven this setup successfully with some big power, most notably a 125 W/ch Yamaha B2 VFet amplifier. Although lacking in visceral impact, they do go very deep (I haven't measured but I can give an educated guess into the low 40Hz range or lower).

    I only have a couple of problems: my current room does not allow the use of them, and I did not heed the warning concerning finishing the baffles with paint or stain or varnish. The baffles are still in their "au natural" Baltic Birch glory.

    Thanks again for making this design so accessible. (BTW: the Yamaha B-2 was producing only 2 Watts/ch MAX when the listener is driven from the room by the SPLs.)

    ReplyDelete
    Replies
    1. Thank you for sharing your experiences.

      Happy listening!

      Delete

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