LNB Para-Lab-Super speakers

So I like to change my speakers from time to time – like all good hifi fools. I was sick of the crappy Kef C40 lumps that I got from freecycle and decided to splurge £100 on a pair of LNB Para-Lab-Supers. They were manufactured in April 1973 so that makes them just under two years older than me. Thankfully, they haven’t been drinking as much beer or eating as many pizzas as me so they are pretty much like new. They used to sell for £52.50 back when my dad had flares, which translates to about ~£600 in modern money. They are based on a ‘Labyrinth’ design featuring a KEF T27 tweeter and Elac 165mm long throw bass unit.

lnb para-lab-super

How do they sound? Well I’m not going to tell you that a veil has been lifted or that I’ve heard things in recordings that I’ve never heard before but I will say they are a LOT better than the Kef C40 floorstanders. This is mostly because they actually have some bass. They fill the largish kitchen-diner quite nicely thank you, and although old fashioned are actually quite smart. [UPDATE] After listening for a while longer I felt they were a bit boomy/woofy. I investigated and found that only the first fold of the labyrinth had any stuffing in it. My rudimentary understanding of this speaker design is that it usually has a consistent filling through the full length of the pipe. I used a basic ‘loft insulation’ style filling from an old sub enclosure that I had lying around and sure it enough it has tamed the wobbly bottom somewhat. It’s very hard to re-stuff this kind of enclosure as the pipe is too small for my hand and arm but I did the best I could and used an equal pre-measured quantity of filler on each speaker. At the request of Andy, a commenter on this post, I also took some pictures of the crossover. It’s a classic bit of Great British veroboard work, but does the job I guess.

LNB Para-Lab-Super inside baffle

LNB Para-Lab-Super

I haven’t verified it but I’m assuming it’s a circuit design ala…

A complete speaker crossover with a 3rd-order high-pass filter on the tweeter and a 2nd-order low-pass filter on the woofer

As I write this I’m listening to the solo from Kid Charlemagne by Steely Dan and it sounds pretty damn good to me – it’s also about the right vintage for these speakers. What’s driving them? Well, a poxy Chinese valve amp called Little Bear. ‘Nuff said.

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11 Comments

Filed under Geeky stuff

11 responses to “LNB Para-Lab-Super speakers

  1. Andy

    Thought I recognised the pic’ I was after those too! Good to hear they are as good as I thought they might be. I have the Paralab 40’s a 3 way design with Dalesford bass, Celestion HF1300 and Coles 4001 and are beautifully detailed but laid back too. If you take them apart for any reason would like a pic if the crossover to compare.

    • Hi there. I am pleased with them. I was surprised to note they don’t appear to be stuffed though. This isn’t normal is it? It might explain the fact that on the more bassy material they sound quite woofy / boomy. I know you have a different model, but are yours stuffed right to the end of the tunnel?

  2. Andy

    PS they are probably better on stands about 8 to 12 inches above the floor

  3. Andy

    Thanks for taking the photos, crossovers in mine on Veroboard too. My 40s are loosely filled with what looks like long haired wool, loosely filled is about all. it looks a bit like the bass unt has been changed, or moved at some point judging by the holes but the main thing is that they sound good. I, think, the sound was improved by rewiring the speakers with some silver coated wite I got from an ebay shop, fairly stiff so was easy to fix and does not flap around.
    Keep enjoying them!

  4. Guy

    Hi there

    A mate of mine has just bought a pair of these and it seems likely the capacitors in the crossovers will need replacing if they’re 40 years old.

    Do you know what the values are, please?

    Thanks.

    Guy

    • Assuming they’re the ones from ebay then I’m the one selling them! You’ll soon see the values when you unscrew the baffles and have a look. It’s dead easy. Hope you enjoy them!

      • Guy

        Hi Dan

        Thanks.

        The difficulty is I’m up in Surrey and my mate is in Bristol. I’m going down in a couple of weeks to see him and put some new caps in for him.

        I need to know the values before I get there so I can hunt through my bag of bits or, alternatively, buy him some. Then I can turn up and fit them. If I can’t find out the values until I get there it makes things a bit complicated.

        I can see from your post you’ve had the fronts off before. Would you be willing to take one off again and let me know the values, please?

        Thanks.

        Guy

    • he’s coming over tomorrow so we’ll whip the baffle off then. Cheers!

      • Guy

        Excellent Dan–many thanks.

        Chris can give me a call once he knows the values.

        Glad to have found your blog.

        Guy

    • Hi Guy,

      I’ve whipped the baffle off and had to unsolder a couple of caps to read them. As far as I can tell (it’s not massively clear!) they are (from top to bottom on this image https://dandini.files.wordpress.com/2013/04/dsc5194.jpg)
      4uF 60v
      1uF 160v
      2uF 60v

      Size-wise, I’d say the largest cap is about 30mm long. Hope this helps,

      Dan

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