The KEF B139 is a fairly stout woofer but it was designed and built before. Homage To The B139 Hi-fi enthusiasts of a certain age (we weren't 'audiophiles' then) always recall KEF's B139 bass unit. For two reasons, principally: first, it wasn't round – often carelessly called elliptical, the diaphragm was actually shaped like an athletics track, with two straight and two semi-circular edges.
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Hi all,I wonder if anyone has the origional article from ETI magazine in the '70s for a DIY transmission line speaker using KEF drivers. ETI used them as their reference speakers for a while. I built these and still use them but have lost the article. Did anyone else here build these monsters?Since I have every ETI issue published, I will have the article. Locating that article will be a whole different can of worms.For the record: The best T-Line design, IMO, was published in Wireless World, May 1972. Bailey's second design and was brilliant. I built mine to that design.
The one and only. Several things to note about the design:. You MUST use sheep's wool (not too much and not too little). The midrange should also be T-Line loaded. Dump the KEF crossovers and use something better (I used Radford crossovers).Zaphod,any further comments regarding the wool?I used it in my Tannoy bass reflex cabs, mainly because it is easy to work with and remove/modify.
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Bought some 500gsm wool doonas off e-bay, cut them into shape and stapled the edges together along the cut edges. Are you refering more to the loose wool?
Zaphod,any further comments regarding the wool?I used it in my Tannoy bass reflex cabs, mainly because it is easy to work with and remove/modify. Bought some 500gsm wool doonas off e-bay, cut them into shape and stapled the edges together along the cut edges. Are you refering more to the loose wool?The wool is essential in a T-Line, due to it's properties. It is less necessary in a reflex design, but it is nicer to work with than the alternatives. The stuff I've used is the long strand stuff.
I tease it out and carefully stuff the line. The one and only. Several things to note about the design:. You MUST use sheep's wool (not too much and not too little).
The midrange should also be T-Line loaded. Dump the KEF crossovers and use something better (I used Radford crossovers).Agreed Trevor, I built a couple of pairs of these back in the early 70's and they were Bailey's design. I may have a copy of that build article too at home in Melbourne and I'll get the boss to have a look for me when I call her tonight.
I also built another of Bailey's designs pretty sure it was his! with the B139 driver flat on the top of the enclosure.I didn't like the sound as much, it was dangerous to have the driver in that configuration easy to damage it and I went back to the original build. Agreed the Kef xover needed tweaking.Cheers,Keith. Zaphod,any further comments regarding the wool?I used it in my Tannoy bass reflex cabs, mainly because it is easy to work with and remove/modify. Bought some 500gsm wool doonas off e-bay, cut them into shape and stapled the edges together along the cut edges. Are you refering more to the loose wool?I used to use long fibre wool in the column and teased out.
I would go around and find the old large onion string bags, tease the wool out through the holes in the bag and hang and stuff the bags in the column. You will have to experiment with the amount of wool you use though.Cheers,Keith. Since I have every ETI issue published, I will have the article. Locating that article will be a whole different can of worms.For the record: The best T-Line design, IMO, was published in Wireless World, May 1972. Bailey's second design and was brilliant. I built mine to that design.Thank you Zaphod, I would greatly appreciate it if you could have a look when you have time.
I liked the Bailey triangular design too and almost built it just to compare the two but the ETI design has the longest line I have seen in any design - there is no output from the open end except at extremely low organ notes.I used long haired wool to fill them (inside a core of rolled plastic gutter guard) but only filled the bends not the straights of the line and it seems to work very well. I have modified the ETI crossovers to free up the bass a bit as they seemed a bit 'dry' sounding in std form. Glad to see there are some TL fans on this site. Edited August 14, 2009 by mulane.
Hi, my father and I built 2 pairs of these in the 70's. I still have mine and although they look pretty crappy now, they still sound like sex in the ears.
Especially with my even older home-made Mullard 12w amp. I can't promise anything but I think I might still have the plans lying around as I remember seeing the receipt for the drivers and crossovers sometime in the last year or so. I'll have a look.Hi Sow Ears. That would be terrific! They're great speakers aren't they? Do you find them a bit dry in std form? Are you still using the std crossovers?
I've upgraded the treble caps from electrolytic to polyester (never could find the paper in oil ones specified in the article) and there was a big improvement in smoothness and detail. Got some Solens too for the midrange ready to be installed if I ever find time. I've always found the midrange a little bit 'squarkey' and I dont know if its merely revealing the source component's weakness or if its the electrolytic caps or the B110s.
I dont think the BBC LS3/5 s 'squark' though so maybe its the caps. Never found a speaker with better bass. Mulane Porker is what porsche owners call a porsche i have a 928 which is called a landsharke.
The ETI design i followed used the same drivers as imf mk4 kef B139 B110 celestion hf1300 hf 2000except they inverted the tweeters and mid. Box makes all other lines appear small even the IMF's. Approx 1.3m tall bloody big 600mm depth+. I am cuurrantly using a cheap response carbon coned driver. It works ok max spl 105 just. Looking at some long throw drivers peerless etc. Everyone that has here'd it is amazed at how low it goes.
Don't know off any comercial subs which can extend as low.sorry about spelling sunday arvo lolRon.
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For additional information, see the Global Shipping Programme terms and conditions – opens in a new window or tab. Buy it now – Add to Watch list Added to your Watch list. Most boom crash HT subs don’t need nor possess any of these qualities. I would be reluctant to ask her just to give them away but if you are at all interested I could ask her if she would take a nominal amount for them.Uploader:Date Added:9 August 2016File Size:58.71 MbOperating Systems:Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/XDownloads:86908Price:Free.Free Regsitration RequiredCreate an account or sign in to comment You need to be a member in order to leave a comment Create bazs account Sign up for a new account in our community.Kef b139 bass APR variable There’s a reason it’s marketed as a subwoofer. Get Started Conditions for uk nectar points – opens in a new window or tab. KEF mid/bass speaker sp pair eBayDescription Postage and payments.
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And if the two woofers are in reverse orientation back to back is usualthe distortion components that come from the cone cancel kef b139 bass bass, which is a nice bonus.Both that and the XXLS kef b139 bass actually very similar – but the Scanspeak is approaching twice the price. I have a couple of these b’s, they are the oval base drivers pulled from a very old 2 way made by kef. Olson is not keen on v139 old KEF drivers. Retrotech Audio – Vintage AudioBack to home page. People who viewed this item also viewed.From what I’ve heard it seems to be a quality control issue, with kef b139 bass units good, others not. Report item – opens in a new window or tab. MF basz, Sep kef b139 bass, If you don’t find them suitable for your purposes lef sure you’d have no trouble finding someone who would like to take them off your hands.
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Accepted, Eligibility for PayPal Credit is determined at checkout.Add to Watch list Watching Watch list is full. It does so by effectively doubling the mass of the driver, thus trading 3db g139 efficiency kef b139 bass the smaller cabinet.International postage paid to Pitney Bowes Inc. Ke about to try a build of another B based classic speaker In the music mode the bass is tight with a fast attack and quick decay. KEF B, BASS SPEAKERS, SP, PAIR eBayIf the intent of the OP was to supplement the output of their existing speakers, then a pair of Bs in kev right enclosure and crossed over at the right frequency and correctly placed in the right spot kef b139 bass the listening room may very well suit the intended purpose if music is the main intended use. Kef b139 bassSep 16, Learn more about your rights as a buyer.The Linn Isobarik uses the principle outlined here So to upgrading the IMFS, the main question is what bass driver to use. You probably wouldn’t know they were on until kef b139 bass off and you noticed their absence.
KEF B139 WoofersBack to home page Return to top. Learn More – opens in a new window or tab Any international postage is paid in part to Pitney Bowes Inc.
Be the first to kef b139 bass a review.Will usually dispatch within 2 working days of receiving cleared payment – opens in a new window or tab. Learn More – opens in a new window or tab International postage and import charges paid to Kef b139 bass Bowes Inc.
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