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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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10th Oct 2019, 4:00 pm | #21 |
Nonode
Join Date: May 2004
Location: Halifax, West Yorkshire, UK.
Posts: 2,587
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Re: Need help identifying a pair of Vintage Speakers?
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10th Oct 2019, 4:11 pm | #22 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
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10th Oct 2019, 6:22 pm | #23 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
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Re: Need help identifying a pair of Vintage Speakers?
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10th Oct 2019, 7:04 pm | #24 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,874
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Re: Need help identifying a pair of Vintage Speakers?
They are exactly the sort of speaker that people sell because they're a bit too big, then spend the rest of their lives regretting it.
That sentiment has been expressed a few times in various threads on here, including about LNB Paralabs. My transmission line jobs are definitely big, but they're part of me and they're staying. So before you sell, ask yourself if you are really really sure. Good speakers are unimpressive, they just vanish and only the music remains. David
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10th Oct 2019, 8:06 pm | #25 |
Triode
Join Date: Mar 2017
Location: Loughborough, Leicestershire, UK.
Posts: 36
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Re: Need help identifying a pair of Vintage Speakers?
My first thought was LNB, but the height doesn't coincide with the info for the models that I've got to hand Photo album
"The hockey stick" moulding that the false front sits in, the feet, white back and terminals are all pretty typical though. I'll speak to dad at the weekend and measure some speakers if I get the chance. |
10th Oct 2019, 8:38 pm | #26 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
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10th Oct 2019, 8:45 pm | #27 |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
But I did spot this on google, these are exactly like mine, and the have the LNB logo too?
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10th Oct 2019, 11:59 pm | #28 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
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11th Oct 2019, 6:43 am | #29 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Re: Need help identifying a pair of Vintage Speakers?
To produce bass audio of a certain frequency of a certain level, you have to shift a certain amount of air. There are no short cuts, no joker card to play.
This implies that anything in a small cabinet will hit limitations it cannot go beyond. Anything in a larger cabinet may be able to do the required air movement but needing high internal pressure changes or large cone excursions which translate into distortion. So you wind up with larger speakers inevitably being less compromised than smaller ones. Many small speakers have been designed to sound impressive by making their low frequency response have a prominent peak just above their low frequency roll-off. This can give appreciable clout to drum sounds but leads to what's called 'one note bass' Most people are used to small speakers and this psycho-acoustical trick. So when they come across speakers which can do accurate bass down to lower frequencies, they are left feeling something is missing... for a while... and then they start noticing things in the music they hadn't heard before. Having unidentifiable speakers without badges can be a hoot! Visitors with audio inclinations see them and hear them, but because they can't identify them, they don't know what they're supposed to say about them. Normally they identify a speaker, remember what an accepted pundit said in a magazine review and then trot out those phrases. No hearing or thinking required, just eyes to see the badge and a very good memory. All that time they spend poring over reviews is for memorising them. If they are ever found to come out with an opinion different to the pundit one, that's their audio cred right out the window Have fun! David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
11th Oct 2019, 9:13 am | #30 |
Heptode
Join Date: Jun 2017
Location: Southport, Merseyside, UK.
Posts: 646
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Re: Need help identifying a pair of Vintage Speakers?
I agree wholeheartedly with the comments about neutral speakers. I had a pair of simiilar Lentek speakers back in the 1980's. Unfortunately they were too large for optimum placement in my listening room.
When pulled out 3 ft or a bit more from the side and rear walls, the stereo imaging was almost holographic|. When there was real bass in the source material, it was really "there" otherwise no false "boom" Such a location was not practicable domestically though.
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13th Oct 2019, 4:03 pm | #31 |
Triode
Join Date: Mar 2017
Location: Loughborough, Leicestershire, UK.
Posts: 36
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Re: Need help identifying a pair of Vintage Speakers?
We can't come up with anything LNB and 69cm tall (which isn't to say that it doesn't exist-the memory is going back between 35 and 55 years!)
Please check the measurements and pop the false fronts off, which might be a task in itself , and post some more photos |
13th Oct 2019, 5:21 pm | #32 | |
Dekatron
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,311
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Re: Need help identifying a pair of Vintage Speakers?
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Cheers, GJ
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13th Oct 2019, 7:36 pm | #33 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Re: Need help identifying a pair of Vintage Speakers?
Even with a nice, linear driver, if the driven volume becomes a significant fraction of the cabinet volume, there is non-linearity in the compression of the air as the pressure is proportional to the reciprocal of the remaining internal volume, not to the displacement of the driver.
As a yank racer once said, 'There's no substitute for cubic inches' David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
13th Oct 2019, 10:40 pm | #34 | |
Dekatron
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,311
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Re: Need help identifying a pair of Vintage Speakers?
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The question is whether 130 is a 'significant' fraction of 10,000. I haven't worked through the algebra, but off the top of my head it feels as though, at the limits of the motion, the contribution to the air spring's total force from the quadratic term is 130/10,000 = 1.3% the size of the contribution from the linear term. Higher order terms will be down by further factors of 130/10,000. There is, in addition, a force coming from the diaphragm's support elements - the cone's surround and any centring spider close to the voicecoil. Since the total restoring force is the sum of the support force and the air spring force the nonlinearity due to the air spring will be diluted further. Would I be right in thinking that at the level of 1.3% the nonlinearity of the air spring won't make an audible contribution to the speaker's distortion spectrum ? Cheers, GJ
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13th Oct 2019, 11:00 pm | #35 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
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Re: Need help identifying a pair of Vintage Speakers?
Probably not, but when you get to some of the units with very long throw drivers in cabinets hardly bigger than the driver...
Anyway those LNBs are transmission line jobs so the pressure from both ends gets used down at the frequencies of greatest excursion and the overall volume puts them well clear of such concerns. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
14th Oct 2019, 6:17 pm | #36 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
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14th Oct 2019, 6:19 pm | #37 | |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
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14th Oct 2019, 6:24 pm | #38 |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
Apologies! My measurements were wrong they measure 76.5x 28.5x 29cm and here is a couple of more pics hope this helps!
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14th Oct 2019, 6:35 pm | #39 |
Triode
Join Date: Nov 2018
Location: Surrey, UK.
Posts: 32
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Re: Need help identifying a pair of Vintage Speakers?
Or inches off the ground it is just under 31 inches x 11 inches x 11.5 inches
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14th Oct 2019, 7:30 pm | #40 |
Triode
Join Date: Mar 2017
Location: Loughborough, Leicestershire, UK.
Posts: 36
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Re: Need help identifying a pair of Vintage Speakers?
Without seeing what's behind the false front, and going on dimensions and some construction cues, I'm guessing series I LNB ParaLab 20s
The dimensions should be around 31" x 11" x 11 1/4" and weight 40lbs. Behind the false front should be a KEF B200, a KEF T27 and a STC4001G. The back is white melamine, which was quite expensive at the time, and the terminal block was made by Carr Fasteners of Nottingham (it still has it's red polarity spot) |