Lentek Monitor X

Discussion in 'DIY Discussion' started by Keepar, Mar 15, 2021.

  1. Keepar

    Keepar

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    Hi, need some specific info re the bass X-over for these speakers. Hope somebody out there is familiar with them? Having rebuilt the X-overs and cured the 'wandering' problem I am not happy with the bass. It is not as powerful or tight. The cap and resistor were changed but the inductors were left as original. Didn't have the means to measure them! I gave in and sent them to Wilmslow Audio who, on bench testing, can find no fault. They have, however, measured the coils at 8.1 and 2.5mH where expected values would be 5.7 and 1.7 ish so I am trying to find out if these are the correct values as defined by Burt Webb who designed them. They are an upgraded version of his Cambridge Audio R50s but he upped the X-overs from 1st order to 3rd order so looking at the R50 X-overs online does not help and, of course, I can find no reference to the specifics of the Lentek X-overs. Somebody out there must know (for certain) what the values are? Pretty please!!
     
    Keepar, Mar 15, 2021
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  2. Keepar

    Sergeauckland

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    The only information I could find was that the crossover frequencies were 350Hz and 3500Hz. Using the inductance values you have and what's marked on the capacitors, you should be able to calculate what the crossover frequencies are, and therefore relate them to the above.

    Inductors generally don't change values with time, they are very stable, so whatever value you have is very likely to have been like that since new.

    One further thought, and it's what I did with my B&W 801s, is to bypass the passive crossovers and drive them active. Now that would be an improvement!

    S.
     
    Sergeauckland, Mar 15, 2021
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  3. Keepar

    Keepar

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    Hi Sergeaukland. Yes know the X-over points and had considered doing the maths (yawn). Assumed the inductors were pretty bomb proof. Will try direct but I'm the kind of person who must have it 'right'. I need to get them back to 'factory fresh'. Obsession rules OK.
     
    Keepar, Mar 15, 2021
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  4. Keepar

    Smiler

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    Hi did you ever find a solution to this problem. I think I can help if you haven't
     
    Smiler, Oct 11, 2022
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  5. Keepar

    Smiler

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    I happen to have a pair of these lovely speakers and I have just updated the capacitors so I can tell you what you need maybe
     
    Smiler, Oct 11, 2022
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