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New Yorks, Tannoy project

Discussion in 'classic' started by cooky1257, May 7, 2017.

  1. cooky1257

    cooky1257 pfm Member

    Early days but first fix of DC 3836/3833 units into DIY Tannoy York cabs(exTonyL).
    The units were flown open baffle-well baffle-less in the National Theatre for a couple of musical productions and barring the odd blemish are pretty mint.

    Should be an interesting week ahead.

    [​IMG]
     
  2. Tony L

    Tony L Administrator

    Cool. DMT15 drivers? I assume the elegant boot-print on the front baffle occured as you had to route the hole bigger to front-load the driver? Are you going to beef the construction up or alter the pizza delivery slot port at all? I think if it was me and I had your woodworking skills I'd plane the front lip off and build another nicer-looking cab around them, i.e. double all the pannel walls from the outside. The baffle is very thin and is likely the weakest link IMO. It is interesting to see how Lockwood get around that one, still a very thin baffle, but much smaller and better supported as it is bolted onto another layer in the cab (the rest of the Lockwoods are covered in Formica which is a seriously dead material so different rules apply).
     
  3. cooky1257

    cooky1257 pfm Member

    Pretty much spot on. The carcass of the cabs is actually really well put together so can definitely be built upon/around. I like the proportions of the rectangular York so whatever I do I'll hang on to that.
    First stop will be to double up the baffle possibly using the grill frame to make a ply/mdf sandwich, though if I take the edges overlap down till flush with the baffle I can use a full width second layer of mdf/ply and round the edges to the top and sides....i need to play with the tuning/porting too.
    Those damping pads you installed are very effective so they stay.
    I'm in no rush though-I have 2 pairs of these DC's, the second pair will go into some system15 clones.
     
  4. cooky1257

    cooky1257 pfm Member

    DC's in the theatre flying frames
    [​IMG][/url]

    The drivers were used enclosure free for vocals mostly.
    The frames would be perfect for measuring larger drivers, T&S parameters for example.

    [​IMG]
     
  5. cooky1257

    cooky1257 pfm Member

    [​IMG][/url]

    Looking a bit tidier and sounding very very good.
    I'm using the xover from the CPA 15 at the minute and must say I'm inclined to prefer the higher xover frequency and steeper slopes to the DMT15...though the tweeter is a tad hot so will damp that down a dB or so.

    The York box is tuned to 45Hz so I'll mod the slot into 2x100x78mm ports to drop it to 37 hz or so and see how we go from there.
    The cabs are incredibly resonant though so much to be done in that department.

    [​IMG]
     
  6. cooky1257

    cooky1257 pfm Member

    Quick and dirty RTA screen grab pink noise @ 1m.

    [​IMG]

    You can see the response drop like a stone below 45hz.
     
  7. orangeart

    orangeart KJF Audio Ltd.

    That are starting to look great now. I really like the style of this speaker.
     
  8. Tony L

    Tony L Administrator

    Never seen the likes of the theatre frames before, most odd. I'd have expected them to have no bass at all and to be all but useless. With a wide baffle attached and flown in a corner they might make more sense. Very strange indeed!
     
  9. cooky1257

    cooky1257 pfm Member

    There is something about the proportions of the Rectangular York that feels/looks dead right to my eyes-The TW driver looks nice on the baffle too.
     
  10. cooky1257

    cooky1257 pfm Member

    Can't have been anything below 200hz-the bespoke frames must have cost as much as the drivers-they are dead heavy/substantial but unfortunately ring like a bell.
     
  11. cooky1257

    cooky1257 pfm Member

    Discovered a fault with one of the drivers in pair No2.
    The driver was fine and free on the inward stroke but on the outward there was what sounded like a coil rub/scratching sound that made for a distorted bass output.
    I cleaned the gap between the former and the pole piece but without clearing the issue. That pointed to the outside of the coil/mag or the area of the former above the voicecoil as the possible problem area ...After a bit of head scratching I was resigned to the fact I may need to fork out for a recone kit (£192) as there is no way to detach the rubber surround without damaging it to get at the v/c.
    I have a few of these DMT series baskets lying around and the magnet is held on with a loctite retaining compound adhesive and 4 allen headed bolts but they are hidden under the spider. Nothing to lose I decided to take the speaker apart.
    The solvent MEK softens the glue holding the spider in place without spreading into the spider proper and after care separation with a blunt blade I lifted the spider to expose the bolts.
    [​IMG]
     
  12. cooky1257

    cooky1257 pfm Member

    After removing the bolts all it took was a sharp sideways smack with a rubber mallet to break the retaining compound. Very carefully lifted the mag off the basket and voice-coil.
    These are precision made, well put together drivers. You can see the copper flux modulation ring on the mag assembly.

    [​IMG]
     
  13. cooky1257

    cooky1257 pfm Member

    On inspecting the v/c......bingo! a bit of swarf or glue was stuck to the inside.

    [​IMG]
     
  14. cooky1257

    cooky1257 pfm Member

    After giving the v/c and gap an extremely thorough clean and covered with tape to prevent any ingress of junk. The next stage was to remove all the old adhesive from mag top plate and basket. The top plate has 4 spigots to locate the magnet assembly precisely and these(and their holes) needed to be spotless as there was zero play-most impressive.
    Loctite 638 and 243 threadlock were used in the reassembly.
    The cone/spider needed to be realigned and glued so the I used shims in the gap to centre everything and evo contact adhesive to reattach the spider. 24 hours later a perfect, fully functioning driver and a very happy me.
     
  15. Dowser

    Dowser Learning to bodge again..

    Wow - nice work!
     
  16. cooky1257

    cooky1257 pfm Member

    Cheers, the reassuring thing too is that you can't misalign the mag/top-plate on the frame thanks to the really tight tolerances.
     
  17. cooky1257

    cooky1257 pfm Member

    Here's a 12" York Minster driver, you can see the AlNiCo magnet/horn assembly bolted onto the same open frame design.

    [​IMG]
     
  18. Tony L

    Tony L Administrator

    I was wondering about that! Good job anyway, do they actually sound/measure the same? I suspect the later drivers such like this are far more accurately machined, the vintage classics have a very hand built/aligned feel to them, not that I'd ever be wanting to take a basket off!

    The Yorkminster driver is interesting; it really does look like a Gold magnet assembly stuck onto a modern basket. I assume the peperpot/horn is very similar too?
     
  19. cooky1257

    cooky1257 pfm Member

    I checked the repaired unit out and its spot on-I now have 6 of them here(I may be going mad;-) to compare and am very chuffed it worked out.

    The YM moving parts are your standard hard edge Prestige LF/HF driver-thjey do benefit from the extra accuracy and consistency CNC machining affords the pepperpot I suppose. Tannoy used this open basket between 1990-2010. the 4 'corner' mounting open frame has been changed to a 6 point circular one but the back end of the basket where the mag attaches is pretty much the same on the latest models.
     
  20. Tony L

    Tony L Administrator

    What is the iPhone analyser app you posted a screen grab from upthread? Looks interesting.
     

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