KEF owners thread

Discussion in 'British Audio' started by matteos, Dec 16, 2014.

  1. Paddy Garcia

    Paddy Garcia AK Subscriber Subscriber

    Messages:
    149
    Location:
    Virginia
    There are discussions of which ferrofluid to use, as the original is apparently NLA. I used the Ferrotec (Kef OEM) universal fluid sold through Parts Express. The anorak set will undoubtedly shiver at the notion, but they sound good and it'd be easy to swap in future.

    Having recapped 2 pairs with Falcon matched caps I don't think I'd recommend. Not hard, especially if you've already got the speakers disassembled, but I didn't notice any real difference that would justify the cost.
     
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  2. Raynald

    Raynald AK Subscriber Subscriber

    Messages:
    4,863
    Location:
    Montreal
    It is nice to hear you plan to restore them to their former glory, keep us posted on your progress.
     
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  3. arts

    arts Super Member

    Messages:
    2,297
    Location:
    Qc, Canada
    The foam donuts certainly do form a seal,and that was the manufacturers intention. The ''tube'' is bonded ( not just structurally,but in an air tight manner) to the pole-piece,which has a central hole to accomodate the bolt that secures the force cancelling rod. When it is all properly assembled,the driver is in a totally sealed enclosure.
    Not having the proper sealing does affect the bass.Trust me on this (note the instrument I'm wearing in my avatar:))

    Not to be a killjoy,but I have seen the rubber surrounds come loose from the baskets,not because of glue or rubber failure,but due to the paint delaminating from the baskets.Go figure....

    Also,pay attention to the rubber grommets in the basket mounting holes. They tend to rot and fall apart.Luckily,they are readily available from any good hardware supplier.

    As for the slight lack of bass,you are correct. These guys start rolling off at 55 cycles,so the absolute bottom octave may feel a little ''light''. Mind you,this can be a very good thing in most rooms. When I have eq'd my guys back up to flat (using KEF's own specs) the bloody crockery keeps falling out of the cupboards.Just for farts and giggles,set a moderately/slightly loud level,then go to another room,preferably one downstairs if possible,and listen for a few minutes.See how fast you're running back up to turn it downo_O
     
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  4. slimecity

    slimecity Super Member

    Messages:
    1,579
    Location:
    New Zealand
    Brilliant, that's what I was after. Cheers for that. I will just focus on the ferrofluid and the donuts then.

    ......and then hours and hours of sanding and re-oiling....lols. And recovering the grilles too.

    It will all be worth it in the end.....
     
  5. ftpols

    ftpols New Member

    Messages:
    11
    Location:
    Yokohama, Japan
    KEF Q60 Capacitors

    Attached is photo of the original crossover . Some of the capacitors are clearly marked as bipolar, the others aren't. The circuit diagram doesn't indicate polarity.

    Can I assume that all the capacitors are bipolar?

    Many thanks.
     

    Attached Files:

  6. slimecity

    slimecity Super Member

    Messages:
    1,579
    Location:
    New Zealand
    I would have thought so - some of those are Bennic and some are Falcon caps. So the Bennics have the additional marking "Bi polar" while the Falcon ones dont, just as a manufacturer marking decision.

    Someone can correct me if Im wrong, but I would always like to fall back on a good schematic (if available) but yea otherwise speaker caps are generally bipolar.
     
  7. ftpols

    ftpols New Member

    Messages:
    11
    Location:
    Yokohama, Japan
    Schematic I have is attached. The metallic blue cap is marked ALCAP 25 MFD 50V +/- 10% VNP. It was the KEF 1000 MFD 25V +/- 20% 1000UKADY that I wasn't sure about.
    Per your kind replyI will take it as bipolar.
     

    Attached Files:

  8. slimecity

    slimecity Super Member

    Messages:
    1,579
    Location:
    New Zealand
    Yup - non-polar is confirmed by the schema.

    Otherwise you would have a polarity marked on the schema for the caps (with a + on one side) or one of the rectangles (there are two coloured black on the schema for each cap) would be white. These methods would both mark polarity.
     
  9. ftpols

    ftpols New Member

    Messages:
    11
    Location:
    Yokohama, Japan
    Many thanks for your time and help.

    I looked at Mundorf e-caps to replace the existing caps, but the service life is only 3,000 hours. Any downside (apart from price and size) in using Mundorf M-Cap MKP Polypropylene Capacitors for this schema, please?
     
  10. slimecity

    slimecity Super Member

    Messages:
    1,579
    Location:
    New Zealand
    Dont worry about that. They will still outlast any electros in an existing xover.

    All caps are sold subject to a service life however we generally still replace them.
     

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