Original article
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| G. A. Briggs |
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| Wharfedale SFB3 |
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| Stereo Sound "Tube Kingdom" 1996 Volume 3 |
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| JE Labs (cheap 😉) DIY version inspired by Stereo Sound as featured in Sound Practices issue 17 "JE Homebrewer" |
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| JEL OB for Altec 755 built from 3/4" Birch plywood ca. 1997 |
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| Built using Tanguile 'tongue in groove' flooring planks for an Altec 605B November 2008 Hi-Fi Show |
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| Mondrian 2011 edition for a 12" driver |
Have fun and happy listening!
Hi.
ReplyDeleteApologies 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
The baffle dimensions should remain the same regardless of number of drivers used. See the Wharfedale SFB3 picture above for multi driver use.
DeleteHappy Listening!
JE
Hi JE.
DeleteTx 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.
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!
DeleteJE
Hi
ReplyDeleteJust 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.
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.
ReplyDeleteI 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.)
Thank you for sharing your experiences.
DeleteHappy listening!
Hello, really appreciate your site and articles!
ReplyDeleteI am considering the build of this OB with Visaton B200. I have the following question: As the driver is sitting very low, what is the hight of the stereo image? Would this be that voices appear be close to the ground or would this be 'normal' hight? I know also depends on room and other factors. But appreciate any experiences on this. Thanks, Wolfgang
If you clicked the "Original Article" text (hyperlinked) at the top of this page, you'll find out that I was a Quad ESL57 listener/owner. This OB fitted with Altec 755As reminded me of the Quads. Food for thought - some people complain about the low soundstage height on this OB but I've never heard the same about the Quad ESL57s. Both speakers share similar dimensions and are tilted to beam towards the listener. Perhaps the "balcony seat" concert hall effect is more noticeable when the listener is less than a meter away. My listening position has always been at least 1.5 meters away from my speakers and the OB/755A presentation is no different to the ESL57s, Silbatone 755A/755C or Altec 753Cs.
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