Zaphod Beeblebrox Posted October 2, 2015 Posted October 2, 2015 (edited) After prompting from another SNA member, I spent some time going through my files and dug out the information on the Bailey transmission line enclosures (as described in the May 1972 issue of Wireless World). I built a pair in 1973 and loved them for more than a decade. Very fine sounding speakers. I am enclosing the full article along with my (1973) hand-drawn schematic for the Radford crossovers. These are ESSENTIAL to gain decent performance from the KEF drivers. It can also be used by those who own the KEF Concertos, for a substantial lift in performance.A few points:* DO NOT use Dacronâ„¢ filling or (shudder) fibreglass insulation. Use only sheep's wool for damping.* Run the midrange enclosure all the way through to the rear of the enclosure, cutting a hole in the back. Ue sheep's wool to damp this enclosure as well. Big improvement.* If using later model B110 drivers (say >1980-ish) then some of the filtering (the parallel resonant circuit - 0.47uF||0.335mH) can be removed from the midrange circuit (replace with a short circuit - obviously), as this filtering is designed to deal with the flaws inherent to the old B110 drivers.* I cannot stress highly enough: USE THE RADFORD CROSSOVERS! Even if you want to renovate a pair of Concertos. MASSIVE difference in sound quality. Bailey-1972-Transmission-Line-Loudspeaker-Enclosure.pdf Radford Crossover.pdf Edited November 17, 2015 by Zaphod Beeblebrox 9
cheekyboy Posted October 3, 2015 Posted October 3, 2015 Hi Trevor, I also built this design back in the mid '70s along with another design in the late '70s that used the B139 driver in the top of the enclosure firing up. I also used sheep's wool in long onion bags and teased it out through the holes and hung the bags in the enclosures. A very decent loudspeaker indeed and I used them well into the late '80s......................as you say, a performance jump for anyone who owns the KEF Concerto loudspeakers too. Cheers, Keith 1
Addicted to music Posted October 3, 2015 Posted October 3, 2015 If you are going to use sheep wool make sure it passes the latest standards for insulation use, not that it effects speaker build but just in case, it has to be treated. If you use wool for building insulation ensure that it gets inspected periodically and also a possible retreat.
cheekyboy Posted October 3, 2015 Posted October 3, 2015 If you are going to use sheep wool make sure it passes the latest standards for insulation use, not that it effects speaker build but just in case, it has to be treated. If you use wool for building insulation ensure that it gets inspected periodically and also a possible retreat. The wool I used back in the '70s and '80s was called long fibre wool and was specifically for use in the enclosures I put it in...................no thought of insulating anything with it and I think for that purpose I'd be looking at product specifically for that purpose too, as I did with my front room here, as it was always going to be a dedicated two channel sound room. Anyhow, it's been 40 plus years since I first started using long fibre wool in loudspeaker enclosures and I still have small amounts of it left today that get used still, if I have the right job for it. Cheers, Keith
Addicted to music Posted October 3, 2015 Posted October 3, 2015 The wool I used back in the '70s and '80s was called long fibre wool and was specifically for use in the enclosures I put it in...................no thought of insulating anything with it and I think for that purpose I'd be looking at product specifically for that purpose too, as I did with my front room here, as it was always going to be a dedicated two channel sound room. Anyhow, it's been 40 plus years since I first started using long fibre wool in loudspeaker enclosures and I still have small amounts of it left today that get used still, if I have the right job for it. Cheers, Keith Wool as a building insulation is a good idea especially in the 90s when the price of wool lost the market and prices dropped, there was a push to use it as a building insulation and some of the stuff that's still out there are non treated, there was also products that was sprayed in, which became useless as it flattened out, the better stuff was the batt version, yes it is a natural fibre and a great insulation but it also attracted certain bugs if not treated.
Sansui77 Posted November 6, 2015 Posted November 6, 2015 (edited) Picked these up for a steal. Need to recap and restore the cabinets. It has the Radford xovers inside. Haven't had a chance to listen to them yet. Edited November 6, 2015 by Sansui77
Zaphod Beeblebrox Posted November 6, 2015 Author Posted November 6, 2015 Picked these up for a steal. Need to recap and restore the cabinets. It has the Radford xovers inside. Haven't had a chance to listen to them yet. Nice catch. With Radfords! Wow. Very scarce. 1
koozoop Posted November 16, 2015 Posted November 16, 2015 (edited) Good evening. I own 2xB139B's, 2xB110B's and 2xT27's and I want to build a TL enclosure. Currently I'm trying to modify David's Triangulated TL design (http://p10hifi.net/TLS/downloads/B139-TTL-map-100707.pdf) to accomodate the B110B and the T27. I was googling for Radford's FN10 XO and I visited this thread. Is that the one you have posted above? What is the value of inductor L4? Did you use a plastic pipe for the B110B as an enclosure or just a square wooden box? Thank you in advance! Edited November 16, 2015 by koozoop
Zaphod Beeblebrox Posted November 16, 2015 Author Posted November 16, 2015 (edited) Good evening. I own 2xB139B's, 2xB110B's and 2xT27's and I want to build a TL enclosure. Currently I'm trying to modify David's Triangulated TL design (http://p10hifi.net/TLS/downloads/B139-TTL-map-100707.pdf) to accomodate the B110B and the T27. I was googling for Radford's FN10 XO and I visited this thread. Is that the one you have posted above? What is the value of inductor L4? Did you use a plastic pipe for the B110B as an enclosure or just a square wooden box? Thank you in advance! L3 and L4 are identical. = 0.335uH. The design you posted uses a line which is too short for good bass performance. I suggest you stick to the original Bailey design, if you want extended, low distortion bass to around 20Hz. I did not use a plastic tube, but rather a heavy cardboard one, which extended through the rear of the enclosure. Were I to build again, a length of sewer pipe would be excellent. Edited November 16, 2015 by Zaphod Beeblebrox 1
djb Posted November 16, 2015 Posted November 16, 2015 Never owned a pair of Concertos but spent some time listening to a pair with Radfords in late 80s Have fond memories of the SQ. Peter I had the wool insulation put in a flat roofed space in early 90s doubt it was treated !! But - thinking more carefully- it came from a source in the wool corp so may be ok
planet10 Posted November 17, 2015 Posted November 17, 2015 RADFORD CROSSOVERS Zaphod, Thanx for posting the XO. I have redrawn it and willput it up on t-linespeakers next to the F11/F12 XO. Also note that for anyone interested in building the Bailey line (the one in Bailey's 1st article) dimensioned drawings are here: http://p10hifi.net/TLS/classics/Bailey-WW-TL-map.pdf I would thou recommend building a modern line that takes advantage of some of the tricks learned since modelers 1st appeared in 1999. http://t-linespeakers.org/projects/vProjects.html dave
Zaphod Beeblebrox Posted November 17, 2015 Author Posted November 17, 2015 Zaphod, Thanx for posting the XO. I have redrawn it and willput it up on t-linespeakers next to the F11/F12 XO. Also note that for anyone interested in building the Bailey line (the one in Bailey's 1st article) dimensioned drawings are here: http://p10hifi.net/TLS/classics/Bailey-WW-TL-map.pdf I would thou recommend building a modern line that takes advantage of some of the tricks learned since modelers 1st appeared in 1999. http://t-linespeakers.org/projects/vProjects.html dave Thanks for re-drawing that. One tiny nit: I reckon Bailey's second T-line (the one I listed in the first article) is, far and away, the best. The line is long and the enclosure is compact.
planet10 Posted November 17, 2015 Posted November 17, 2015 I reckon Bailey's second T-line (the one I listed in the first article) is, far and away, the best. I'd agree, but the modern lines are better. dave
Zaphod Beeblebrox Posted November 17, 2015 Author Posted November 17, 2015 I'd agree, but the modern lines are better. dave The 2.4 Metre high one would probably sound better, but all the others have lines which are too short for good bass. The push pull ones would have more upper bass, but will still lose out to the original in the low end. The nice thing about the Bailey T-line (the 1972 variant) is that no sub is needed for 20Hz.
ArthurDent Posted November 17, 2015 Posted November 17, 2015 Having built several Transmission Line systems using all sorts of designs and drivers all I can say is it's hardly worth the effort involved and if you don't think there's a lot of work involved in building them you'd be mistaken. You can get far better performance out of a properly designed sealed enclosure for far less complexity, cost and work. TL's offer very little in the way of bass extension and have inherent problems in the upper bass region which even with DSP are a pain to fix. IMO, YMMV, blah blah...
planet10 Posted November 17, 2015 Posted November 17, 2015 The 2.4 Metre high one would probably sound better, but all the others have lines which are too short for good bass. The push pull ones would have more upper bass, but will still lose out to the original in the low end. The nice thing about the Bailey T-line (the 1972 variant) is that no sub is needed for 20Hz. All 3 of those TLs are the same… 2 of them with double drivers. We have built the tall one. Tremendous performance dave
planet10 Posted November 17, 2015 Posted November 17, 2015 Having built several Transmission Line systems using all sorts of designs and drivers all I can say is it's hardly worth the effort involved and if you don't think there's a lot of work involved in building them you'd be mistaken. You can get far better performance out of a properly designed sealed enclosure for far less complexity, cost and work. TL's offer very little in the way of bass extension and have inherent problems in the upper bass region Not the experience here. We have build some really good TLs. The last 4 ML-TLs have tremendous performance. They all use modern tricks that help improve the low pass function of the terminus… tricks not used in the classic TLs, where one is faced with the conundrum of too little damping to get more bass extension, or heavy damping to kill the unwanted ¼ wave harmonics. dave
Sansui77 Posted November 17, 2015 Posted November 17, 2015 Not the experience here. We have build some really good TLs. The last 4 ML-TLs have tremendous performance. They all use modern tricks that help improve the low pass function of the terminus… tricks not used in the classic TLs, where one is faced with the conundrum of too little damping to get more bass extension, or heavy damping to kill the unwanted ¼ wave harmonics. dave Dave, What would it cost to build the set of TL's your talking about?
Zaphod Beeblebrox Posted November 17, 2015 Author Posted November 17, 2015 Having built several Transmission Line systems using all sorts of designs and drivers all I can say is it's hardly worth the effort involved and if you don't think there's a lot of work involved in building them you'd be mistaken. You can get far better performance out of a properly designed sealed enclosure for far less complexity, cost and work. TL's offer very little in the way of bass extension and have inherent problems in the upper bass region which even with DSP are a pain to fix. IMO, YMMV, blah blah... I agree that, since the early 1990s, building T-lines is really all about the love. Modern computer modelling and modern drivers makes designing a great sealed or vented enclosure so good, so fast and so easy, that building a T-line is really not viable. That said, the second Bailey T-line is still one of the best things you can do with a set of KEF drivers from the Concertos. It's easy, cheap and offers genuine 20Hz performance.
planet10 Posted November 17, 2015 Posted November 17, 2015 (edited) What would it cost to build the set of TL's your talking about? Cost of the one's of which i refer depend to a large extent on the cost of the drivers (and in Oz the cost of plywood). These use the limited edition Mark Audio woofer #6 which were $30 each (before i EnABL them): These use Peerless 830870 -- quite amazing how much bass can be had out of these 4"era. We also did a variation with 4 drivers/box. These use the samedrivers as in the 1st pic, but in a longer line. And our 1st exampleof a proper MTM -- XO frequency is less than the ¼ wavelength of the driver's C-C. Our latest which uses the Mark Audio Alpair 12pw ($135 USD each at Madisound/$173 AUD at d'Archer) Next up is one with 2 x Silver Flute W14/box ($20 USD each) dave Edited November 17, 2015 by planet10 2
koozoop Posted November 24, 2015 Posted November 24, 2015 Will this crossover work as it is for the B139 since the B200 is recommended on the schematic? Has anyone tried any of the No.5, 5ab or 5c versions of the original Concerto crossover that falcon-acoustics offer?
planet10 Posted November 24, 2015 Posted November 24, 2015 (edited) My bad… i used another XO map as a starting point and neglected to change the name on the bass driver. Should be fixed now. dave Edited November 24, 2015 by planet10
Sub Sonic Posted November 24, 2015 Posted November 24, 2015 Cost of the one's of which i refer depend to a large extent on the cost of the drivers (and in Oz the cost of plywood). These use the limited edition Mark Audio woofer #6 which were $30 each (before i EnABL them): These use Peerless 830870 -- quite amazing how much bass can be had out of these 4"era. We also did a variation with 4 drivers/box. These use the samedrivers as in the 1st pic, but in a longer line. And our 1st exampleof a proper MTM -- XO frequency is less than the ¼ wavelength of the driver's C-C. Our latest which uses the Mark Audio Alpair 12pw ($135 USD each at Madisound/$173 AUD at d'Archer) Next up is one with 2 x Silver Flute W14/box ($20 USD each) dave Hi Dave, A little OT but what is your opinion of the 12p in comparison to the 7.3, running full range and disregarding SPL capability? I've just started playing around with a pair of 7.3s... Cheers! Matt
planet10 Posted November 24, 2015 Posted November 24, 2015 (edited) The A12p will have greater dynamics & SPL potential just because it has considerably greater cone area. Personally i prefer the A7.3 in terms of the sonics and its greater DDR/detail. Each treated. The A10p is a good compromise with near the same dynamic capability of the A12p and DDR much closer to the A7.3. Or add helper woofers to the A7.x and make a FAST. dave Edited November 24, 2015 by planet10 1
Sub Sonic Posted November 24, 2015 Posted November 24, 2015 Thanks Dave. I'll have a closer look at them :-) Regards, SS
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