As of late I've become interested in OB. And I am not talking about those narrow high OB's that have the woofer dialled in through some large inductor with all kinds of additional filtering.
The Wharfedale Sand Filled Baffle had one 10" and one 12" Fullrange driver parallel connected with optional a tweeter through a 4 uF capacitor.
I've found the overall dimensions but I want to know the exact location of the 10" and 12" drivers and hopefully someone who has one of these open baffles will be so kind to measure it up and post it here.
A bonus would be to get the size of the handgrips on the sides.
Thank you in advance! AM
The Wharfedale Sand Filled Baffle had one 10" and one 12" Fullrange driver parallel connected with optional a tweeter through a 4 uF capacitor.
I've found the overall dimensions but I want to know the exact location of the 10" and 12" drivers and hopefully someone who has one of these open baffles will be so kind to measure it up and post it here.
A bonus would be to get the size of the handgrips on the sides.
Thank you in advance! AM
Thank you, I was already aware of the OBL7, 9 and 11 but that website does not give me the information on the exact location on the 10" and 12" drivers.
Briggs believed he could achieve the results of the ESL 57 with normal drivers and experimented for months with different configurations ranging from a single driver to 6 drivers. He also warns against using elaborate crossovers.
I've also found a website which appears to have a chapter from a book in which Briggs describes a DIY version. JE Labs Arkiv: G. A. Briggs - Open Baffle. However I like to mimic his original version instead although so far I have been unable to find out much more about the drivers used.
There is also a source that ranks the SFB more or less on par with the Quad ESL57. Innerworld Audio - Whaferdale SFB3
I regard the SFB as a "poor man's ESL 57" and since ESL is outside my financial reach I want to make a SFB clone.
Briggs believed he could achieve the results of the ESL 57 with normal drivers and experimented for months with different configurations ranging from a single driver to 6 drivers. He also warns against using elaborate crossovers.
I've also found a website which appears to have a chapter from a book in which Briggs describes a DIY version. JE Labs Arkiv: G. A. Briggs - Open Baffle. However I like to mimic his original version instead although so far I have been unable to find out much more about the drivers used.
There is also a source that ranks the SFB more or less on par with the Quad ESL57. Innerworld Audio - Whaferdale SFB3
I regard the SFB as a "poor man's ESL 57" and since ESL is outside my financial reach I want to make a SFB clone.
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excerpt from the Innerworld Audio article:
There are no doubt numerous DIY versions of this concept - JE Labs goes into some length here:
http://jelabsarch.blogspot.ca/2012/06/open-baffle.htmlhttp://
Frankly, something like the OBL11 project seems more practical in terms of using contemporary drivers to achieve similar results
I found this slightly amusing as well:
From my reading of the entire article, I don't think the 3" upfiring tweeter could be described as "optional" - and a faithful homage to the original design would depend on drivers with similar performance to the very limited production units described of over 50yrs vintage.
There are no doubt numerous DIY versions of this concept - JE Labs goes into some length here:
http://jelabsarch.blogspot.ca/2012/06/open-baffle.htmlhttp://
Frankly, something like the OBL11 project seems more practical in terms of using contemporary drivers to achieve similar results
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I'll be watching this as I happen to own the drivers, that is if the W70 has essentially the same stuff. Definitely a Super 3. I struggle to see vintage bass drivers succeeding in an open baffle given their minimal x max and thermal limitations.
I think it's a W70. The surrounds are green felt and the cones are dated l964. Thrift store, 40 bucks. Now there's a pair of EV Royal 400s, similar vintage. 18" bass, 8" mid, horn tweet. Sounds better than it should, stock, except for the buzzing enclosure; $45. Need to get my Eico Stereo 70 running.
I think it's a W70. The surrounds are green felt and the cones are dated l964. Thrift store, 40 bucks. Now there's a pair of EV Royal 400s, similar vintage. 18" bass, 8" mid, horn tweet. Sounds better than it should, stock, except for the buzzing enclosure; $45. Need to get my Eico Stereo 70 running.
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I have worked on three sets of the SFB/3s in the past decade with one pair remaining and currently on loan to a close friend...who's been unwilling to return them despite already owning a set of Tannoy Monitor Gold 12s and a set of the ESL57s.
I will try and get you measurements as soon as I can.
You are aware that the two main drivers 12" and 10" drivers for the SFB3s were specific to this unit and employed longer throw voice coils? I've had a chance to measure them against what some misguided souls have tried to substitute other Wharfedale 12" and 10" drivers for defective SFB/3 units.
Additionally Briggs' use of a SFB baffle contributes, in no small measure, to their superb performance.
Alas, GB, often seemed to get distracted with new, and mostly inferior, designs and the SFB3 design was relegated to relative obscurity while clearly inferior products such as the W60/70/90 and others marked the d-evolution of subsequent Wharfedale offerings.
The ESL57 was, is, a remarkable loudspeaker particularly its airy HF and MF reproduction, but it had/has a few significant weaknesses...weak LF response, narrow sound-stage and the need for its own on-board power supply.
The beauty of the SFB/3 was, and is, it's x/over simplicity, high sensitivity, wide sound-stage, and excellent LF response and it comes within a breath of rivaling the ESL57s in HF and MF response and for my money a better overall loudspeaker for a wider range of music.
The W70 drivers are nothing like those found in the W70s, 90s..even the Super 3 was a special design for the SFB/3.
Careful - some '57 fanboys (myself not included) might take umbrage at "significant weaknesses" 
Oh, did we forget to mention room placement issues, and limited dynamics / SPL in stock trim?
I personally reached the same conclusion when I owned a pair in the early 70s, but that was driven by the 33/303 - a not inexpensive combination perhaps not Quad's highwater mark.
clearly that qualifies me as a pariah - but WTF do I care ?
There are many who consider properly updated / modified / rebuilt 57s, particularly multiple stacked pairs thereof, to be "pretty darned special" - and certainly there are more of them still roadworthy than other competent but under appreciated systems of that era - SFBs among that count.
Oh, did we forget to mention room placement issues, and limited dynamics / SPL in stock trim?I personally reached the same conclusion when I owned a pair in the early 70s, but that was driven by the 33/303 - a not inexpensive combination perhaps not Quad's highwater mark.
clearly that qualifies me as a pariah - but WTF do I care ?
There are many who consider properly updated / modified / rebuilt 57s, particularly multiple stacked pairs thereof, to be "pretty darned special" - and certainly there are more of them still roadworthy than other competent but under appreciated systems of that era - SFBs among that count.
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Assuming the drawing of the OB11 is to-scale (which I think it is, using a ruler, you can extract the dimensions quite accurately for purposes of building an OB). But really this was designed for the custom JA 8 inch driver and JA waveguide with Audax tweeter - if you go that route I am sure TG will throw in the baffle dimensions for free.
Btw, TG did a fantastic job with the selection of drivers and XO as usual. I am sure it sounds great but take a look at the cost of those XO components and I say you are way better off to get a DSP and mutliple class D amps. You will have some hope of getting the XO and the integration correct. My 2 cents...
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Assuming the drawing of the OB11 is to-scale (which I think it is, using a ruler, you can extract the dimensions quite accurately for purposes of building an OB). But really this was designed for the custom JA 8 inch driver and JA waveguide with Audax tweeter - if you go that route I am sure TG will throw in the baffle dimensions for free.
Btw, TG did a fantastic job with the selection of drivers and XO as usual. I am sure it sounds great but take a look at the cost of those XO components and I say you are way better off to get a DSP and mutliple class D amps. You will have some hope of getting the XO and the integration correct. My 2 cents...
With all due respect to TG...whom I've corresponded with as he did not have an actual set of the SFB/3s to work from..his iteration bears little resemblance to the SFB/3 other than approximate cosmetic similarity.
It's wildly unpopular among many, it seems, to think that a vintage design created without today's manufacturing processes, technical modeling and measurement tools could be considered as anything but pedestrian..and yet we have dinosaurs like the ESL57 and SFB/3, among others, that defy those judgments.
I'm a fan of Gilbert dipoles. I also like the ceiling firing flooder tweeter concept.
The question is what current production drivers to use ? In original SFB3 both 10" and 12" drivers are used without any filter. There should not be any serious cone break up issues for this way to be possible. Propably some of the bigger full range drivers could find a place here too. I'm thinking about Supravox 285GMF for example. That's actually a 11" driver. It could be suplemented by 215RTF. Then some cone tweeter, maybe even a 2" or 3" fullrange.
Nevertheless, I would expect it to sound 'thin', afterall it's a dipole without any electrical dipole roll-off compensation. For a certain types of music it may not be problem though.
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The question is what current production drivers to use ? In original SFB3 both 10" and 12" drivers are used without any filter. There should not be any serious cone break up issues for this way to be possible. Propably some of the bigger full range drivers could find a place here too. I'm thinking about Supravox 285GMF for example. That's actually a 11" driver. It could be suplemented by 215RTF. Then some cone tweeter, maybe even a 2" or 3" fullrange.
Nevertheless, I would expect it to sound 'thin', afterall it's a dipole without any electrical dipole roll-off compensation. For a certain types of music it may not be problem though.
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Briggs own description at JE Labs Arkiv: G. A. Briggs on Open Baffle is quite extensive.
"there is no particular virtues in its dimentions, which may be modified to suit individual requirements". The baffle was made when 78 rpm records still were made and it was mono not stereo for the most part. I am sure Briggs used good use of what was aviable at the time but it is product of its time. I have heard the ELS57 and when seated at the right hight they are very good. If you strictly recreate the SFB with drivers that are close to 60 years old. I am sure one can build better SFB like speakers using modern driver, modern construction material and other modern tools. The fineite element analysis and fouriertransformations for time domain studies that are possible today. My own plan for an SFB interpratation is using vintage but not that old alnico drivers and use a slightly more elaborate crossover than one single cap but not going the OB11 way
If it ever comes of the backburner I will post it.
"there is no particular virtues in its dimentions, which may be modified to suit individual requirements". The baffle was made when 78 rpm records still were made and it was mono not stereo for the most part. I am sure Briggs used good use of what was aviable at the time but it is product of its time. I have heard the ELS57 and when seated at the right hight they are very good. If you strictly recreate the SFB with drivers that are close to 60 years old. I am sure one can build better SFB like speakers using modern driver, modern construction material and other modern tools. The fineite element analysis and fouriertransformations for time domain studies that are possible today. My own plan for an SFB interpratation is using vintage but not that old alnico drivers and use a slightly more elaborate crossover than one single cap but not going the OB11 way
If it ever comes of the backburner I will post it.
devil - thanks for saying that - while something like the SFB design wouldn't suit my personal domestic constraints, it's not hard for me to imagine that a salient feature of its design is the upfiring tweeter.
I've built a couple of very modest designs with dual Mark Audio drivers in which one is top mounted. Compared to a variation on the same design with a more conventional bipole arrangement of the same drivers, the up-firing model delivers a much wider and deeper ambient sound soundstage, and has the advantage of greater placement flexibility.
I've built a couple of very modest designs with dual Mark Audio drivers in which one is top mounted. Compared to a variation on the same design with a more conventional bipole arrangement of the same drivers, the up-firing model delivers a much wider and deeper ambient sound soundstage, and has the advantage of greater placement flexibility.
Modelling and simulating is one thing - we all know things that simulated well yet did not work properly after being build. If simulation would be the end-all, be-all then we would have no need for testifying planes, test driving cars etc. I don't think so.
Have you personally even listened to the Wharfedales SFB/3? Do you realise that these and many other speakers were evaluated by Briggs against the live performance of musicians?
The Innerworld article states:
QUAD and Wharfedale embarked upon a series of Live vs. Recorded recitals between 1 Nov 1954 and 9 Oct 1959. A music critic for the Liverpool Post attending such a recital in September 1957 stated “… in two delicious pieces for oboe and piano. Anyone who listened to this with closed eyes, …would have been hard put to detect the change over from ‘live’ to recorded sound - certainly as far as the oboe went; the piano accompaniment also very deceptive.
and later on:
What should also be remembered is that Briggs, by design, marketed these speakers for their magnificent ‘stereo’ performance when bought in pairs - surely among the first!
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Sorry phivates....they are fine within their limitations and were not actually Gilbert Briggs inspired but a product of a disastrous partnership with B.I.C. an American company that also handled distribution of Garrard, Leak and other British-made products and some assembly of Wharfedale speakers here in North America.
I've owned a dozen examples of the W,60, W70, W90 and others and they were better than many many of their American-made counterparts...what I meant to point out is the drivers in these units were not those used in the SFB/3....I'd be more than happy to meet you at the dump and take them off your hands
The Panneau plan by Supravox has all the ingredients required. Likely the value for the inductor connecting the 285GMF needs to be changed. http://www.supravox.fr/kits/panneauplan.pdf
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