Wharfedale SFB sizes anyone?

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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.

Thank you in advance! AM

I know its a bit late....

Print a picture of said 'speaker.
Draw a line through 10" driver, divide by 10 and you have rough inch scale good enough for job.

I've used this to draw my own three view drawing an plan for a scale model aero-plane with no existing full-size drawings or air-frame to go from.
 
If by GSR you mean GRS then the two units that come to mind are the GRS15PF-8 and the GRS12PF-8, both available at Parts Express. However, these two units are best used in sealed box enclosures. In a vented enclosure, no matter how large, there's a nasty bump around 100hz. Optimum volume for the 12" unit is about 75 cubic feet. How such a speaker will perform in an open back enclosure is unknown. I'll look around P-E for a speaker that will give extended bass in a very large enclosure; the theory being it should perform well in an open back system. Take, for instance, the Wharfedale W12 FS or CS. It likes a vented cabinet of several cubic feet and will work in the SFB, as the FS and CS units are much the same as the SFB units. I'd hazard a guess the spider is different to control diaphragm excursion without adversely affecting Fs.


There is a piccy of the rear of the SFB in post 42, if memory serves me well. but here it is again. the dimensions of the SFB are 34"W by 31"H by 12"D. Also, the 12" and 10" units are wired in parallel, probably 15 ohms each and without a high pass filter on the 10" to limit the lows. This may have been safe in the days when 20 watts was a lot but with todays arc welder amplifiers, I'd limit the lows to above 70hz (first order) or 50hz (second order). The Super 3 tweeter is high pass filtered with a 2.2uF cap, (PIO) paper in oil but any decent 50 volt NP cap will work and P-E has plenty. Of course, if you're using modern drivers, they can handle a lot more power than the old Wharfies.


For any of you Wharfie fans here, the foam used for the original annuli is available at The Foam factory. Here's a link to that page. The thickness is 1/8th inch.
https://www.thefoamfactory.com/opencellfoam/charcoal-R.html


I see that my Wharfedale pages have been noted here. Thanks much, GM.
I'm currently working on a study of the open back cabinet. Harry F. Olson in the 40's did such a study but it's written in a manner understandable only by another acoustical engineer, which I am NOT, so interpreting his math into English is going to be a tough nut to crack. Fortunately, I have the test equipment to facilitate that, a large back yard, and no one to tell me I can't. I'm single and retired.


Robert
 

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Colin, thanks for the link to Jordan Designs. The tech papers have been saved for further study. As for Briggs' publications, I have two; a 4th edition (Jan 1955-soft cover) titled LOUDSPEAKERS, The Why and How of Good Reproduction and HIGH FIDELITY, The Why and How for Amateurs (1st edition, May 1956-hard cover) as well as the biography written by David Briggs, A Pair of Wharfedales)


In the paper titled The parameter Game, Mr. Jordan has beaten me in an expression I've used frequently which states 'Too many people pay too much attention to their systems and they miss the music.' Mr. Jordan's words, and I quote, "Words like 'music' and 'listening' seem almost outdated.

He also hit the infamous nail on its head when he commented on computer aided designs whereby the designer seems to forget the meaning of the word 'aided' and thus design the system by the computer, which has no ears. I refer you to a page in my website, A Short Note. (The 15 years mentioned is referenced to when that page was written and uploaded in 1997.)


https://www.ln271828.net/note.htm


Robert
 
This is what I arrived at. Baffle is narrow since the W15 is in a U-Baffle and cuts out around
250HZ. W12 is full range as in the original SFB3. W10 is trimmed a bit at the top end.
Super3 has a 2uf cap. The W15 gives excellent tight bass and I suspect better than the original design. In addition I biamped theses drivers (W15) so they can be attenuated with the chip amp. All other drivers driven with a 5w SE Ampex Tube Amp. Some of these videos have different xover components. IE: 2mh coil on W12. This website is a huge inspiration. Can’t thank Robert enough.

Wharfedale SFB3

Sample Video if my system:

YouTube
YouTube
YouTube
YouTube
 
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