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Tannoy Lancaster cabs

Discussion in 'classic' started by calorgas, Apr 3, 2021.

  1. calorgas

    calorgas Ratty bumpkin

    I have pair of Lancasters here fitted with 12" Golds (rubber surrounds). I know the general consensus on Lancaster cabinets being one of the weaker ones and have been round this loop before (rehoused the last drivers into chunky ply cabs) but this time I am not pursuing that approach, and want to see/hear what improvements I can squeeze out of the Lancaster cabs.

    So anyone reckon they have made any worthwhile improvements to Lancaster cabs with a few tweaks? So far I'm thinking of adding a horizontal shelf to brace the front and sides, and the rear panel can screw into that too. The other thing is maybe attaching some self adhesive deadening sheets under the wadding.
     
  2. s1h1

    s1h1 performing within expectations

    From an email from Paul Coupe about my Lancaster corner cabs…

    "They improve with some internal treatment including bitumen-elsto-polymer treatment such as 2,mm SoundClear coatings to internal rear panels, and 50mm modern acoustic foam lining (coeff adsorption: 0.7), that and a couple of internal braces."

    HTH.
     
    Rockmeister likes this.
  3. calorgas

    calorgas Ratty bumpkin

    Sure does, thanks, as it seems like I'm on the right track.

    So perhaps modern acoustic foam is better than the original wadding then. Cost aside, new lining would actually be less hassle than re-stapling the wadding.
     
  4. sybil

    sybil pfm Member

    I'm certain you could improve them greatly but for 12" Golds they are still below optimum volume. I would start by working out what loading you were considering - 12" Golds in Lancasters were sealed, right? Once you've decided that you can work on cabinet treatment.
     
  5. Tony L

    Tony L Administrator

    Other way round, 15” are sealed, 12” have the port open. The thing that confuses me a bit is I thought 12” Lancs were hard-edge and Chatsworths rubber surround, though Tannoy did some pretty odd things at times.
     
    sybil likes this.
  6. calorgas

    calorgas Ratty bumpkin

    I'm not sure I've ever seen Chatsworths with hard edged drivers but there are lots of Lancasters fitted with 12" drivers with rubber surrounds, in fact both my pairs have been like that. This pair defo all original; serial numbers of driver/cabinet stamp/label all matching.
     
  7. Tony L

    Tony L Administrator

    Interesting. Tannoy history is very hard to pick apart as there is little official documentation and the serial numbers between pairs can be thousands apart. I wonder if the RS was just a revision/later version? They certainly seem way, way more common than the hard-edge 12”. I’m also curious why the RS never found its way onto the 10” 3LZ, which I’d have thought could do with a bit more excursion.
     
  8. calorgas

    calorgas Ratty bumpkin

    Yeah it's all a bit unclear to me too why they used the rubber surrounds in such a limited way; some 12" Golds and some 10" HPDs only, then reappeared on the SRM10b etc.

    I'm also not clear on whether the Golds with rubber surrounds was just the later pairs of if they produced hard edged at the same time. I figure they may have done them in tandem, unless the Chatsworth RT only came in later in the Monitor Golds years, which is possible?
     
  9. sybil

    sybil pfm Member

    In that case off the top of my head I reckon you could improve the Lancasters pretty simply by doing the following:

    Additional brace across the centre as you’ve described, additional bracing from centre brace to top and bottom panels.

    If I recall correctly the 12” in Lancaster’s had a sub baffle? You could probably remake something more substantial for this. You could also fill in the rectangular port hole and retrofit a couple of decent tubular ports to your desired bass alignment (probably EBS).

    Fit some blocks of solid hardwood to the bottom of the cabs to receive short spikes.

    Maybe remake the back panel out of 18mm birch ply?

    Plus damping and wadding as recommended by Paul.
     
  10. Tony L

    Tony L Administrator

    More of an ‘adapter plate’ than a ‘sub baffle’, basically a way of mounting a 12” driver in a cab with a hole for a 15”. Why they didn’t just make two different baffles, one with a 12” hole and port slot, the other 15” and sealed is beyond me. It seems way more faff bolting additional things in than just doing it right from the start!
     
  11. calorgas

    calorgas Ratty bumpkin

    The oldest Lancasters did just have a 12" cut out for the 12" drivers, so you'd think the change must have been for convenience.

    I did think about changing the rectangular port but am undecided at the mo. May start with the basics of braces and panel deadening and see how it goes. Not committed to pimping the hell out of them :D
     
  12. cooky1257

    cooky1257 pfm Member

    Out of curiosity if Tannoy have been lazy and these have 12Rs and the 10x3x4 3/4" port the box is tuned too high for that driver(fine for the 12HE). Reducing the port opening to 85 x 76mm and the same port depth of 120mm with an L shaped blank will tune the box correctly@39 hz -you can try it before you glue in place and see if it's to your taste.
    I'd suggest a simple slightly offset 2x1" H brace on back panel that has the front to back brace meeting the 'crossbar'.
     
    Last edited: Apr 9, 2021
  13. calorgas

    calorgas Ratty bumpkin

    Yes it is those dimensions so I'll play around with reducing the port opening as you suggest. I like your suggestion for the rear panel too.
    I take it that modern acoustic foam is considered better than the wadding Tannoy used? Not seen any definitive info on old vs new material as yet.
     
  14. cooky1257

    cooky1257 pfm Member

    I'd just refluff the wadding myself..
     
    calorgas likes this.
  15. calorgas

    calorgas Ratty bumpkin

    Dragged them out into the garden this weekend and got the shelf/bracing in, rear panel made more substantial and now also screws into the shelf. Had to remove all the side wadding to do this, so that's been fluffed up a bit during refitting. Can certainly feel the difference to the side panels when music is playing, much reduced vibration especially around the height of the shelf and below. Haven't really decided whether the difference is audible as they've been out of my system for a week or more and my ability to make a comparison based on memory is pap, but they're sounding very good!

    Didn't get around to adjusting the port dims so will play around with that when I have some more time.
     
  16. ToTo Man

    ToTo Man the band not the dog

    Should've done one cabinet at a time as this would've given you the opportunity to A/B. :)
     
  17. calorgas

    calorgas Ratty bumpkin

    Haha yes that would have done it I suppose but I'm far too impatient to have taken that approach; more efficient to do them both at the same time!
     

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