Tannoy CPA 12 Cabinets

Discussion in 'DIY Discussion' started by Dev, Feb 20, 2011.

  1. Dev

    sq225917 Exposer of Foo

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    Dev check you haven't knocked the bass driver magnet, they are prone to coming loose apparently- you can glue them back one with epoxy according to the nl.site.
     
    sq225917, Apr 30, 2011
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  2. Dev

    Dev Moderator

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    Thanks Simon, I'll check it when I next remove the driver from the cabinet. I now like the speakers enough to want to veneer and finish the cabinets. So I'll concentrate on that first.
     
    Dev, Apr 30, 2011
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  3. Dev

    cooky1257

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    Dev, it's worth having a tweak with the HF resistors, another 6ohm in parallel with the first may give back some of the top Simon hinted at.
    As for the bass unit, after you've checked the mag-you really have to whack one to shift the magnet inspect the spider to see it it is well glued down- I had something similar with my 15's only to discover a stray pine needle from a Christmas tree had become stuck in the gap. On a happier note the price of a re-cone kit has come down a lot direct from Tannoy, circa £65 !!! and it is an easy job to do if you do the preparation right.

    Cooky
     
    cooky1257, Apr 30, 2011
    #63
  4. Dev

    Tenson Moderator

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    Also check where the wires go from the binding posts to the voice coil. They usually glue onto the voice coil former or near that, and it is common for the glue to come a bit loose or simply for the wire to move so it touches on the spider or cone at high excursion. If it isn't touching on the spider or cone, still give the point where it glues a nice blob of PVA.
     
    Tenson, Apr 30, 2011
    #64
  5. Dev

    Dev Moderator

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    To be honest Frank, I'm now quite pleased with the speakers. So, I've been listening to them instead of fiddling. I'll tinker after I've finished the cabinets. Any advice on veneering? and a good source of veneer sheets?, preferably self-adhesive sheets.
    I must have missed Simon's post. I can't recall it.
    This may be beyond my ability guys, I may ask Lockwood to take a look. To re-iterate, the farting noise is only heard on very low bass (at the start of the first track of Sting's A Brand New Day for example) and quite high volume (and only on one speaker, so it's definitely a fault). At normal volumes they sound fine to me.
     
    Dev, Apr 30, 2011
    #65
  6. Dev

    Dev Moderator

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    Any recommendations for veneer suppliers guys?
     
    Dev, May 7, 2011
    #66
  7. Dev

    nando nando

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    roger can help you both with grills and veneer suply :)
     
    nando, May 7, 2011
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  8. Dev

    cooky1257

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    Dev,

    Rotate faulty driver 180' and while you are at it check there aren't any wires that may touch rear of cone on large excursion, also check the plastic lead-out wires/terminal that clips on to the speaker basket is securely pushed on.

    Cooky
     
    cooky1257, May 7, 2011
    #68
  9. Dev

    Dev Moderator

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    Frank, I checked and there was nothing anywhere near the bass cone that would touch it during large excursion. I'll take out the driver again as soon as I get a chance and rotate it by 180'. I may have to move the crossover inside the cabinets though because bass cables will follow a longer route and may not be long enough to leave the crossover out of harm's way outside.
     
    Dev, May 7, 2011
    #69
  10. Dev

    RobHolt Moderator

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    If you don't play them loud enough often enough I wouldn't spend money on a Lockwood rebuild. Use them with a view to replacing the driver with a better Tannoy 12" DC at some point.
    Padding down the tweeter is palliative - it isn't a particular good tweeter from what I heard (and we measured) and the bass driver is also peaky at the top end.
    Pulling down the entire tweeter output with resistors reduces the peakiness in the presence area but also subdues everything above that point.

    Bass and lower mids are excellent which indicate a very nice cabinet - but it needs a better driver IMO.
     
    RobHolt, May 7, 2011
    #70
  11. Dev

    Dev Moderator

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    What you are saying is perfectly logical Rob, but the speakers don't sound bad to me now, measurements notwithstanding.

    What other 12" DC will be a good match for a sealed cabinet of around 140-150l? (thinking longer term).
     
    Dev, May 7, 2011
    #71
  12. Dev

    RobHolt Moderator

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    I don't follow the Tannoy 'thing' closely enough but i would imagine the 12" Gold would work given there were sealed versions of the lancaster. Well, leaky if not quite sealed :)

    Or make a nice adaptor ring and fit a 10" - that's probably what I'd do as i'm still not entirely convinced that super large bass/mid drivers are the way to go in a 2-way.
     
    RobHolt, May 8, 2011
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  13. Dev

    Dev Moderator

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    Rotated the driver and checked cables (found nothing wrong) and the fault is still present :(.
     
    Dev, May 8, 2011
    #73
  14. Dev

    sq225917 Exposer of Foo

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    Pull the tweeter off the back and see if it still happens.
     
    sq225917, May 8, 2011
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  15. Dev

    cooky1257

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    I haven't heard your drivers but Robs comment re the tweeter makes me suspect you could have a problem. The 33mm tweeter/tulip is common to a lot of Tannoy's modern DC's and is a very good unit. However, it is ferrofluid cooled and if the driver was pushed in its previous life the fluid may have boiled off leaving a sticky goo in the gap-easily cleaned and recharged.
     
    cooky1257, May 8, 2011
    #75
  16. Dev

    Dev Moderator

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    Why do you guys live so far away from Ilford? :D.

    I'll try and take a look, but am nervous:(.
     
    Dev, May 9, 2011
    #76
  17. Dev

    nando nando

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    dev nice to have made the trip to your other side of the world, we got lost on the way back, but was great to see you, that fault on the right spkr still puzzled me, when i fealt the cone i did notice a contact with the coil , still i did not like those ceramic resistors in the cross overs, i found the high and mids missing, but we will get there, lovely cabs, thanks dev,
     
    nando, May 9, 2011
    #77
  18. Dev

    Dev Moderator

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    I'm not sure much mid and high there is on Raggae :).
     
    Dev, May 9, 2011
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  19. Dev

    RobHolt Moderator

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    Tweeter response was bit strange:

    [​IMG]
     
    RobHolt, May 9, 2011
    #79
  20. Dev

    nando nando

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    rob, i went to dev's house and heard them, i was not happy with the ceramic resistors or their valuo, the stranges thing was on a perticular cd with deep bass at low volume really sounded like the bass cone was blown, but other music with out deep bass was fine, however the tops and mid had no life?!!?
     
    nando, May 10, 2011
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