Hi Jason...I'm relatively certain I sent a set of Wharfedale 12" LF drivers to you from Winnipeg, Manitoba, CANADA on behalf of another friend of mine...your OB implementation of Wharfedale drivers just seemed so familiar.
I doubt that my opinions are any better formed than yours but like you I really respected Mr. Briggs intuitive approach and his willingness to acknowledge competitors, contemporaries and his own design and marketing mistakes.
I wish I had a better aptitude for the objective scientific side of Audio but I don't. so I use experience, observation and experimentation.
In the case of the SFB/3 Super 3...it features an aluminum dustcap (which extends it's frequency response by a couple of khz...and it is a longer throw driver...the coil is longer than the ordinary Super 3 and like all the drivers in the SFB/3 were specifically designed for that unit and that unit alone..a point underlined time and time again in Wharfedale literature...I've worked on restoring several sets of the SFB/3s now where unsuspecting owners attempted to substitute other Wharfedale drivers for knackered original SFB/3 versions...the negative sonic results were and are obvious. This is particularly true of the non SFB/3 Super 3s. The biggest problems seems to be with the polyfoam surrounds which if exposed to certain conditions..not sure what exactly (my guess is not enough humidity) can dry out and deteriorate. The surrounds on my SFB/3 drivers luckily were and remain perfect to this day.
Because BIC Industries pulled a number of quick ones on poor old Gilbert quality control and consistency of the W60s 70s 90s was spotty...I've had dozens of sets where the drivers weren't even the same...some AlNiCo, some Ceramic, etc. etc...and ditto on the surrounds!
In fact, GB actually had to plant his own informant at the BIC offices to keep an eye on the various short-cut shenanigans employed by his American distribution and manufacturing partners.
That's why the Made in England stuff is so dear to me...never ran into a set or instance where the drivers were mismatched or differed...
I tend to like all the Super 3s in an OB over their original enclosure implementation
The Wharfedale company always put the date of manufacture on the speaker cone(handwritten and signed by the assembler) and this is useful information when checking if the speakers that have been obtained from factory assembled cabinets correspond to the era that model was made.In Australia the majority of the Wharfedale speakers were sold as raw drive units and only a few of the complete English cabinet models appeared here until the late 1960's when Rank promoted newer versions..The raw drive units always matched the description shown in the brochures.However I am reminded of the fact that demand from the late 50's onwards,outstripped supply to the degree that purchasers here would wait several months for delivery.A full order book is a wonderful experience,but fraught with difficulties if you are in a country where venture capital is limited and a factory and skilled work force need to be expanded,not to mention the supply of parts,especially the fully machined magnets from Swift Levick & Sons.As devilindetails is covering some of the happenings at B.I.C. regarding assembly issues,this may have been the same supply problem and the factory staff may have had to resort to lash ups to keep production running to satisfy orders.The SFB/3 in its earliest forms was fitted with the friction inner support washer,used a straight sided cone,aluminium dome,gold painted frame.The first alnico/alcomax magnet had a flux density of 1.3T and this was followed by an improved type which raised the flux density to 1.45T.It can be recognised by thicker front and rear plates,if the transfers have vanished.Yes,it was fitted with a black muslin bag as were all the models without a corrugated cloth rear suspension.It should be borne in mind that the Super 3 had to match the sensitivity of the W12,W15 and Super 12 speakers and in some cases, doing so facing upwards when used as an omni-directional source.
VaNarn,
Well the plot has certainly thickened. Apologies for my fellow countrymen's shoddy business practices. Everything is expendable in service to the all mighty dollar. This information may explain Troels Gravesen's less than stellar measurements.Of this formerly well reputed tweeter. Is that foam disc the friction gasket you refer too? That would be a tricky restoration to pull off. what diameter (tolerance) for the disc? What density for the foam?
How thick should the disc be? The oppertunities for error are myriad.
While it may not be a function of the high sensitivity, these drivers seem to manage surprising image clarity as well as a deep sound stage despite the fact that they are expected to do this while facing upward. The large magnet which has been abandoned by many manufacturers for economic considerations cannot be ruled out as a major factor in the unique voice of this tweeter. In addition to the light paper cone and temperamental if ultimately fugitive suspension. Thank you for the additional background. Really helpful.
As a side note:
What connection if anything more than a nod of recognition lies between the wharf. Super3 and the Audio Nirvana namesake?
Well the plot has certainly thickened. Apologies for my fellow countrymen's shoddy business practices. Everything is expendable in service to the all mighty dollar. This information may explain Troels Gravesen's less than stellar measurements.Of this formerly well reputed tweeter. Is that foam disc the friction gasket you refer too? That would be a tricky restoration to pull off. what diameter (tolerance) for the disc? What density for the foam?
How thick should the disc be? The oppertunities for error are myriad.
While it may not be a function of the high sensitivity, these drivers seem to manage surprising image clarity as well as a deep sound stage despite the fact that they are expected to do this while facing upward. The large magnet which has been abandoned by many manufacturers for economic considerations cannot be ruled out as a major factor in the unique voice of this tweeter. In addition to the light paper cone and temperamental if ultimately fugitive suspension. Thank you for the additional background. Really helpful.
As a side note:
What connection if anything more than a nod of recognition lies between the wharf. Super3 and the Audio Nirvana namesake?
Leo,
Missed your post when I replied earlier. Thanks for filling in the blanks as well. My plan is to find a pair of SFB3 (maybe the ones from London, the member not the city) in working condition and compare them to the ones I have. If all else fails I can open a small museum of sorts that features my rather tidy collection of infirmed vintage Wharfedale tweeters. I have again wandered naively into something that grows increasingly complex and by extension problematic. The quote in your profile comes to mind.
You did comment on a thread I started regarding my Goodmans Triax. There is a lingering question about whether the magnet is feroba or alnico. In the process you visited my gallery at image shack were you got a glimpse of the
wood and metal frankensteins I call open baffles. That may account for your deja-vu. If you want to send me a pair of W12's I will not protest.
- Jason
Rockaway,I view Troels experience with the Super 3 as typical of what can be experienced with the model of that period.I can just make out the date of manufacture as Dec '63.This is about when the production of the SFB/3 ceased.Yes the 1/8'' thick foam disc is the friction support which is clamped in place with bakelite washers.What Troels pictures show is the slightly curved cone from the later ceramic version and it would not surprise me if the coil was unequally positioned in relationship to the pole plate and the coil winding not thoroughly coated for rigidity. I prefer a corrugated disc suspension and a surround that is one piece without the overlapped joins.Modern speakers are more likely to be flatter in freq. response as the need for maximising efficiency is not as great a priority as in the past, this means, improved cone materials and techniques can be used.Early speaker design,when reproduction from gramophone recordings happened to be the source material,tended to compensate for shortcomings in the recordings and in the pickups. The latter items often dipped in response in the low trebles and followed this with a peak anywhere in the 12 to 18 kHz area for the truly better models.Remember too,that the record companies made discs that were intended for the majority of users and unfortunately Hi Fi enthusiasts were small scale on the consumer sales list.Wharfedale ,under Briggs control, did wonders in achieving realistic results given the conditions and his various publications helped in providing understanding of what leads to better reproduction and especially of speaker technology,although this is now mainly of historic value.Only David Dicks can answer your query on the Audio Nirvana models and if there is a design philosophy connection to the vintage Wharfedales.
In search of modern replacements I came across these:
Check out the felt? surounds and the phenolic spiders. Lightweight paper cones as well. The only thing more obscene than the magnets is the price.
URL=http://imageshack.us/photo/my-images/547/imagehyv.jpg/]
Check out the felt? surounds and the phenolic spiders. Lightweight paper cones as well. The only thing more obscene than the magnets is the price.
URL=http://imageshack.us/photo/my-images/547/imagehyv.jpg/]
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Any drivers come to mind that might offer some of the sonic character of the
Super3 without the attendant disadvantages?
All that is needed to optimise the Super 3 are the skills and knowledge of what is required for the correct assembly and of course spare parts ,such as the voice coil if this is burnt.The cone made for the ceramic magnet is fine(as is the ceramic magnet version itself),it just requires a better suspension. Any speaker that is going to vie with the transient performance of the Super 3 at its' best is going to need a magnet of a similar flux rating,if not higher and the same attention to the low overall mass of the moving parts. A modern coil,such as an edge wound aluminium type,given availability,would give an improved thermal rating by virtue of modern adhesives and former material.
VaNarn,
You use two terms (Skill and Knowledge) whose rarity and elusiveness have made them nearly mythological entities, at least here in the states. As others who may posses these qualities have passed on the opportunity to restore these, it looks as though I will have to rise to the occasion. What do you make of the drivers I posted above?
- J
You use two terms (Skill and Knowledge) whose rarity and elusiveness have made them nearly mythological entities, at least here in the states. As others who may posses these qualities have passed on the opportunity to restore these, it looks as though I will have to rise to the occasion. What do you make of the drivers I posted above?
- J
I view the the pictured speaker model as indicative of a product that requires a plethora of adjustments to overcome the wide tolerance variation of hand made parts.It is certainly a step back to early construction methods and given all the assembly stages and component parts required would be by implication,an expensive product.Whether its' performance justifies the cost would require a listening test in an appropriate enclosure and possibly an objective measurement to verify the makers' specifications.Picture wise it is an impressive thing. There is retired (due to ill health) Wharfedale repairer in Melbourne,Norman Edge; his method of obtaining parts involved salvaging from the cheaper Wharfedales i.e the Bronze magnet models.This is a course that I have pursued when needing parts for repairs other than winding replacement coils to suit.This is not a problem for copper wire,but enamelled aluminium wire is not readily obtained in small quantities and I would appreciate it if someone could advise me to the contrary. The nearest wire gauge that confirms to the Super 3 coil is SWG 37 (.0068" bare D).
Excellent points. Home spun, small run speakers like those above and PHY, to name another must like Wharfedales suffer from wide spread to simply periodic, inconsistencies in quality control brought on by material sourcing variations. Most of the vintage speaker guys here have used up their inventory of spare coils and other miscellaneous parts and consequently are not willing or able to take additional steps. I did find a guy on eBay who uses hemp cones (hempapotomus , I believe is the company name) and says he has industry connections to wind coils of any type. I will update if this pans out. Are there any threads on DIYAUDIO that cover hand winding? I have not come across any. -j
I've written something answering somebody's doubts, it was either the electromagnetic speaker builder or the one who is building that incredible "spherical" 3 way speaker made out of "petals" or "lamelles".
I understand both projects are still in construction.
But I covered only roundwire.
I have edgewound homemade "ribbon" (actually flattened roundwire) but it was *very* difficult.
I understand both projects are still in construction.
But I covered only roundwire.
I have edgewound homemade "ribbon" (actually flattened roundwire) but it was *very* difficult.
A final and sobering addendum: I am a high school teacher ( a sobering thought alone).
Today, a student tested my hearing with a tone generating ap for the ipad. I was shocked to discover that I only hear to just shy of 14Khz! At levels above 17K many students turned with pained expressions and pleas to stop the torture. I have always considered my hearing to be quite good and perhaps better than my student's. It was a humbling moment. This puts the tweeter search into a whole new light as I am only using my current tweeters within a functional window of approximately 11khz between 3k and 14K.
Today, a student tested my hearing with a tone generating ap for the ipad. I was shocked to discover that I only hear to just shy of 14Khz! At levels above 17K many students turned with pained expressions and pleas to stop the torture. I have always considered my hearing to be quite good and perhaps better than my student's. It was a humbling moment. This puts the tweeter search into a whole new light as I am only using my current tweeters within a functional window of approximately 11khz between 3k and 14K.
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