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This is the first Archived Forum which was active between 17th April 2007 and 1st March February 2012

 

Latest post 12-19-2010 3:33 PM by Evan. 12 replies.
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  • 11-29-2010 7:42 PM

    • Evan
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    Misc repairs

    Okay guys this is not a B&O project so be nice Big SmileStick out tongue
    I ask here because I know many of you are helpful regardless, as you probably dabble in other brands as well.

    I have a pair of Realistic Optimus T-120 3-way speakers im fixing up for my father as a chrismas present.

    Foam:
    I am going to undertake the refoaming of the 4 woofers, even though I am completely inexperienced Indifferent
    The drivers are 5" and 10". I need to find a place to get the foam rings from and learn how to measure them out properly, help?

    Caps:
    The originals are 4uF and 8uF, one for each crossover. This morning I purchased a pair of 4uFs and 10uFs. Will I be abe to notice the difference between a brand new 8 or 10? The man behind the counter told me they are REAL close. What would the difference be?

    I also need to recover the frets, but the local fabrics store didn't have anything suitable. Sources?

    Thanks for the help!

    Oh and I realize that I have a project already running, but this is sort of taking priority -Christmas coming up and all!

    Evan

     

  • 12-01-2010 9:50 AM In reply to

    Re: Misc repairs

    Hi,

    refoaming is not very difficult, it just needs time. You can buy them here... there are many suppliers.

    http://cgi.ebay.de/10-zoll-hochwertige-Schaumstoff-Sicke-Speaker-Ring-/270389679719?pt=DE_Lautsprecher_Martin&hash=item3ef47b1667

    It is a differnce when you replace a 8uF cap in the crossover by a 10uf type... and it is not necessary to use a different size. 8.2uF Wima are available. Use a good MKP or MKS cap... i prefer WIMA, Intertechnik, Audyn or Mundorf (probably the best stuff ever built...).

     http://cgi.ebay.de/2-x-MKTA-8-2-uF-160V-MKT-Folienkondensator-/140478746090?pt=Lautsprecher_Selbstbau&hash=item20b52f8dea

    http://cgi.ebay.de/2-x-Audyn-Cap-MKP-8-2uF-250V-radiale-Bauform-/160508194371?pt=Lautsprecher_Selbstbau&hash=item255f08ae43

    http://cgi.ebay.de/2xMundorf-Kondensator-MCap-Supreme-8-2uF-Selektiert0-6-/260688573581?pt=Lautsprecher_Selbstbau&hash=item3cb23ff48d

    Martin

  • 12-09-2010 10:39 PM In reply to

    Re: Misc repairs

    Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!

  • 12-17-2010 10:48 AM In reply to

    • Evan
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    Re: Misc repairs

    Thank you both! For some reason I did not notice anyone replied to my thread.

    Fortunately I was able to find the parts and pieces. I have MFD and Sprauge/Goodman Atom caps.

    3 of the 4 refoam operations were successful. 1 of the 10" woofers is misaligned. Is there any easy way to fix this? It only rattles at a long throw or about half volume. This is kind of an emergency since I am gifting them in a few days!!!

    Thanks again guys!

    Evan

     

  • 12-17-2010 11:34 AM In reply to

    • Dillen
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    Re: Misc repairs

    There's only one thing to do with the misaligned woofer - cut the
    surround and dustcap off, align and refoam again.
    Sorry but you cannot correct it any other way.
    It is essential to align the spider/center piece/coil etc. properly before glueing in the new surround
    as you can read many other places on these forum pages (but not on the suppliers websites, they just
    tell you how easy it is without aligning!).
    A success rate of 75% is not the worst result, I've heard and hopefully that woofer can still be rescued,
    from what you tell it should be possible so long as you don't play it any more before it is refoam'ed.

    Martin

  • 12-17-2010 6:34 PM In reply to

    • Evan
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    Re: Misc repairs

    Hello Martin, thank you for your reply.

    What is so irritating is the fact that I did align the woofer. (I didn't align the mids, both work great!) The other subwoofer was aligned too. I was very pleased with my work, especially since it was my first time refoaming anything. I even put the inner edge of the rings behind the woofer as they were originally!

    When the original foam on the woofer failed it was used for quite a long time in the damaged state. Is the speaker permanently damaged? Doomed?!

    BTW the inner edge of the foam rings was quite small and had to be stretched quite a lot for me to get them on, <-- problem?

    If it doesn't make a rattle/knock noise at low volume is it safe to use? I would like my father to be able to enjoy his present while I am away or until I can get it fixed.

    Thanks again!

    Evan

     

  • 12-17-2010 6:38 PM In reply to

    • Evan
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    Re: Misc repairs

    EDIT

    Evan

     

  • 12-17-2010 7:30 PM In reply to

    • Evan
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    Re: Misc repairs

    Die_Bogener:

    Hi,

    It is a differnce when you replace a 8uF cap in the crossover by a 10uf type... and it is not necessary to use a different size. 8.2uF Wima are available. Use a good MKP or MKS cap... i prefer WIMA, Intertechnik, Audyn or Mundorf (probably the best stuff ever built...).

    Martin

    I have not heard these speakers in many years, what would the difference be exactly? I mean they sound decent, but they are connected to a worthless amp (10% THD!) right now. My 3000-2 is on the bench too!

    Oh and BTW, they were both 50v but now 100v.

    Evan

     

  • 12-18-2010 12:18 AM In reply to

    • Dillen
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    Re: Misc repairs

    You stretched the inner lip of the new surrounds to make them fit ?
    (How on earth did you do that ?)
    Yes, that's the problem, I'm sure.
    It's probably just a matter of time before one or more of the other woofers
    show the same problem too. The foam material needs to be "at rest" when
    done (and not playing), tension will cause problems.
    Try to find surrounds that fit the actual woofer.
    Like many other B&O woofers they look standard but are not.

    Martin

  • 12-19-2010 12:43 PM In reply to

    • Evan
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    Re: Misc repairs

    I stretched them dry and left them to resize overnight. Once completely on, the fit was snug but not as tight as you think.

    When I ordered my things, the web site (simply speakers) even listed my driver model number as applicable, even listed as the very first one.

    Evan

     

  • 12-19-2010 1:21 PM In reply to

    • Dillen
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    Re: Misc repairs

    The surrounds will try to shrink back to their cast shape.
    One of butyls good properties is exactly that.
    Therefore, it's essential that the surround is "relaxed" when mounting.

    I'm amazed at the number of B&O speaker owners that report of
    woofer surrounds that were sold to be a guaranteed fit but wasn't.
    Some were even far off.
    And what puzzles me even more is that the same suppliers keep listing
    and selling the same junk.
    I don't dare to think how many speakers were thrown out because even
    skilled DIY'ers didn't manage to get it right.

    Seeing that this supplier lists the same surround as suitable for
    both the MS150 and the M75 makes me sad.
    The sizes stated doesn't match any of them particularly good.

    Thanks for sharing your experiences. Surely that will save other
    Beoworlders from similar troubles.

    Martin

  • 12-19-2010 2:33 PM In reply to

    Re: Misc repairs

    I've ordered some cheap ones and dust caps from the US bay site, for 8" S45 and for 6.5" RL 140, will come back with report, when i get it.

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250740941075&ssPageName=STRK:MEWNX:IT

    I have here 4 6.5" to play with, and for the S45s its serius, I will shim and do my very best. Big Smile

    Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!

  • 12-19-2010 3:33 PM In reply to

    • Evan
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    Re: Misc repairs

    I guess what made me think it was ok was the fact that the instructions said a difference of up to 1/8" is acceptable.

    I agree with you Martin, this isn't the right way to do it.

    Evan

     

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