T27 cannot be paired with B139 at all. Standardly paired with B110 (as mid bass in 2way or as mid driver in 3-4way).
Leading to something like this? One thing worries me - there is a largish empty chamber below and a smaller triangular one above the Babylab. These I assume will resonate so will need treatment? The bottom one could be filled with sand for deadening and stability?
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Thankyou.
Elliot Audio in Oz has published a guide for this: https://sound-au.com/tsp.htm
I agree it would be useful to do this - although measuring frequency response would have to be left to mid-spring or so - I'd have to do this outside in a field.
New B110s and T27s from Falcon are not cheap (standard British understatement) and that's a risky investment with old B139s. It was indeed my first thought until I saw the prices!
I already said, that B139 is not the same as the newer one which is combined with B110/T27/Coles4001G, forget about those combinations. What is available is used, B139+T15+new Super tweeter (Vifa from China), a new box similar to the old one (if possible bass reflex or only larger volume compression box according to the actual TS parameters) and a new crossover modeled according to the old one. Everything else is a failure and out of budget.
I don't know what to say about the measurements. If this is not your last project, buy a USB measuring microphone. Dayton or similar. Measure the TS parameters according to the ARTA instructions, and you also have REW free software for all those measurements. You can measure the FR range in the room, at 1m and then at 2-3m (where you listen). It is worth more to you than the measurement in the meadow, because it also shows the influence of the room. The speaker is listened to in the room, not outside, and should be adjusted accordingly for best result.
I use ARTA (LIMP) and the additional mass method with Blu Tack.
I don't know what to say about the measurements. If this is not your last project, buy a USB measuring microphone. Dayton or similar. Measure the TS parameters according to the ARTA instructions, and you also have REW free software for all those measurements. You can measure the FR range in the room, at 1m and then at 2-3m (where you listen). It is worth more to you than the measurement in the meadow, because it also shows the influence of the room. The speaker is listened to in the room, not outside, and should be adjusted accordingly for best result.
I use ARTA (LIMP) and the additional mass method with Blu Tack.
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Assuming the B139 is XO'd over at say 300-350 would the T15 cope with that? (The Celestes XO'd over at 1,000 I think - and never sounded quite right to my ears). To my musician frame of mind A=440 is what an orchestra tunes to, and the open second string on a violin - 220 being then a tone above the open bottom string (G) - the violin is hardly a bass instrument. Super-tweeter also - I'm sure I read somewhere that the T15 tops out around 16,000?
I could measure the B139s come spring - try them out with the T15s using a replaceable baffle - and then with a separate box for a MA A5.3 blanking off the T15s. I've long wanted to try the latter out on their own anyway
I gave my opinion, and you manage as you know. 🤣
You can take some cheap full range driver 3-4" and cross it with B139 low, say 200-300Hz. In that case it is just a bass helper. However, the power of that driver is low, the impedance is higher than 8 ohms, low efficiency and old age, I would not spent a lot of money on it. If it's a nostalgia project, do as close to the original as possible.
Lets say 4pcs of that one (serial connection of two drivers for 8 ohm):
https://www.aliexpress.com/item/32949180213.html
Or 2pcs of that one:
https://www.visaton.de/en/products/drivers/fullrange-systems/b-80-8-ohm
https://www.visaton.de/en/products/fullrange-systems/stella-light
You can take some cheap full range driver 3-4" and cross it with B139 low, say 200-300Hz. In that case it is just a bass helper. However, the power of that driver is low, the impedance is higher than 8 ohms, low efficiency and old age, I would not spent a lot of money on it. If it's a nostalgia project, do as close to the original as possible.
Lets say 4pcs of that one (serial connection of two drivers for 8 ohm):
https://www.aliexpress.com/item/32949180213.html
Or 2pcs of that one:
https://www.visaton.de/en/products/drivers/fullrange-systems/b-80-8-ohm
https://www.visaton.de/en/products/fullrange-systems/stella-light
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Of course 🙂 . It is much appreciated and I thank you kindly for your input and time - especially as I have neither the knowledge or experience to work this out on my own
No.
And 1 kHz is probably too low, although it is not a tweeter but a mid/tweeter (39mm coil). I guess the nasty breakup mode from the B139 was suppressed in the crossover.
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You can pick up the B139 B110 and T7 in a Kef 104 AB speaker or similar second hand in Australia for around 400 to $600 marketplace on Facebook. If the drivers are all ok that is a bargain, and they will be well run in. I have a pair of LS35A speakers with the T27 and the B110 drivers and they are awesome. The second-hand market is pretty good for the B139 driver, and you can often get them in pairs. Condition is everything mind you.
The B139 is a great Piston bass driver and was the best I had heard in the 70, s and 80, s but a little slow by today's standards with a bit of mass behind it. The B110 are nice but a bit coloured and I am talking about the sound of these Drivers that I still have and bought around 1987. I always liked the T27 tweeter and found it great for its time and I found the older the T27 tweeter was made the better it sounded. I am not sure if the new drivers from Falcon Acoustics are a newer design and better materials.
New Falcon/KEF drivers are expensive. £900 for B139/B110/T27 two box driver kit only, excluding postage, crossover, wiring and box. It takes about as much to get two finished speakers, and maybe more. I believe they are of good quality and made to original specifications, but at that price, it's not worth it unless you need to replace the drivers on some existing speakers. Individual drivers are more expensive than a set. Expensive nostalgia.
https://www.falconacoustics.co.uk/d...b139-drive-unit/falcon-b139-b110-t27-set.html
https://www.falconacoustics.co.uk/d...39-drive-unit/r50-b139-b110-t27-4001-set.html
https://www.falconacoustics.co.uk/d...b139-drive-unit/falcon-b139-b110-t27-set.html
https://www.falconacoustics.co.uk/d...39-drive-unit/r50-b139-b110-t27-4001-set.html
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They are standard range designs rather than premium range ones from 50+ years ago. They are not competitive with modern standard range drivers never mind the modern premium range ones they are priced against. If you have well liked 50 year old speakers with failed drivers they are worth considering. If you are building a retro speaker (e.g. a 70s transmission line), not that bothered about technical performance and price is not a significant consideration then they might be worth considering for a new DIY build. For most DIY builds though these days they are not going to be on a list of drivers to consider. It doesn't make them bad drivers just specialised ones that are inappropriate for most DIY requirements these days.
I have listened to those KEF combinations many times. Even today, there are many fans of that sound, soft, smooth, precise, linear, and for me personally a bit boring. Top HiFi from the past. Anyone who has some old, well-preserved speakers can get a lot out of replacing the capacitors and wiring. And it's not a big deal or a big price.
I think that's what is called the 'British sound'? Correct me if I'm wrong. I grew up with that sound - and today I like it for certain music and the particular mood I'm in. Which is why I'd like three pairs of speakers in the same room!
Incidentally I've come across one speaker that seems not to fit that description - a pair of Celestion Ditton 15s. An old girlfriend of mine (and that dates this back to at least 27 years ago) once remarked she didn't like them overmuch. So the conversation went along the following lines..
'What's wrong with them?'
'They're all tits and bum'
'Eh?'
'If those speakers were a woman she's have manufactured tits that stick out too much and a large flabby ****'
As a description of them it's stuck with me - a pity she wasn't a magazine hifi reviewer in the 70s as that in print would have been priceless.
I don't think the British sound exists in reality. KEF, Tannoy, Wharfedale, Celestion and many others, all of them are a different school of sound. Plus from model to model, there are big differences.
The biggest problem is with the speakers. Amplifier, preamplifier, CD player, DAC, Tuner, you can make it sound the same or very similar to something else, but speakers are difficult. Distortions, non-linear amplitude and phase, polar characteristic, room interactions, etc. A slightly smaller problem is with turntables. In principle, wherever there is a mechanical-electrical conversion, there are many problems.
The biggest problem is with the speakers. Amplifier, preamplifier, CD player, DAC, Tuner, you can make it sound the same or very similar to something else, but speakers are difficult. Distortions, non-linear amplitude and phase, polar characteristic, room interactions, etc. A slightly smaller problem is with turntables. In principle, wherever there is a mechanical-electrical conversion, there are many problems.
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