Tannoy Mansfields For refurb

P

Pac67

Guest
Picked up some uber-rare Tannoy Mansfields for restoration yesterday (had hoped they were serviceable but read on!). These were made in limited numbers for studio work mainly so very few found their way into domestic duties. This particular pair were a special order for a musician and resided in his living room from brand new. What are they? We'll, they're around the size of the Tannoy Berkeley speakers (just under 3ft high, 2ft wide and just over a foot deep). What makes them unusual are that unlike many of the larger Tannoys, they're infinite baffle and designed for high power handling (relatively speaking...remember these were made in 1974!).

_MG_6075_zpsb47e5081.jpg


The other thing that makes them stand out is the build quality of the cabinets. Not your average flimsy and poorly made Tannoys these. Front baffle board is 3/4 inch ply and the other panels are just under an inch and made from a very dense small particle chip board which seems to be quite dead when "rapped". Base is near identical to modern Prestige Tannoys being a ply frame with metal dome runners in each corner. All in all very substantial, heavy and stiff, just the way Tannoy should have made all of their cabs. I imagine that part of the reason for the build robustness was that unlike domestic monitors, these were designed to have a long lifespan being bashed about studios so needed to be up to the task!

O.K. It's here at this point I hold my hands up and admit I didn't even check them before buying, just handed some wads of cash over before the bloke selling them changed his mind! I had hoped they would be serviceable but budgeted for a rebuild if not. This is what I found behind the grilles:

_MG_6078_zpsd35519c2.jpg
#

A few clues there as to the drivers employed...have you worked it out yet? Disintegrated foam surrounds...12 inch driver size, made in 1974...got it yet?

They're 12 inch HPD 315's. I thought I'd better whip them out and strip them just to check everything else was ok as surrounds aren't too bad a job.

_MG_6074_zpsde5e605c.jpg


Sequentially numbered drive units looked mint (they usually do if they've been un-molested). Removing the cable to the crossover I tested the LF and HF units and got (respectively) 6.3 Ohms and 10.6 Ohms (other unit within a few percent of this) so am happy knowing that there's no open circuits which would otherwise have signified coil damage.

Closer view of cone!

_MG_6072_zps85dac247.jpg


It's not as bad as it looks, honest!

Wiring internally was another surprise. Not sure about other vintage Tannoys, but the cabling seemed to be in reasonable order, not too corroded at the ends and substantial gauge. Best of all, the 4 pin connector to the driver is MUCH better quality than the modern plastic block connectors. In fact the whole drive unit construction (bar the surrounds) is of better quality than the newer ones. Sound wise, this does not imply they'll sound better, just that construction quality left little to be desired, something which has been lost today by the addition of the necessary evil of having accountants on management teams! (the reality of modern economies).

Rear of one of the speaker units:

_MG_6077_zpsef5cc8cf.jpg


Closer look at cabinets:

_MG_6076_zps91e196ac.jpg


These are both as near to mint as you're ever likely to find. I struggled to see even a small scratch on these. However, I will be giving the finish a new lease of life with a slight gentle rub down and some coats of Carnauba/Beeswax.

Crossover panels removed from the inside of the cabinet (right at the bottom so you have to reach down and grab them when the retaining blts are removed!). They look minty and original with no leakage evident from the caps. I may replace the caps in any case and although there are alternatives to the original crossovers, I want to keep these original so will only replace like for like. Next out will be the shoddy quick release binding posts...truly horrid things. Will replace these with quality pure copper CNC Reds or WBT binding posts which may involve reaming out the crossover panels to accept them plus a little soldering/rewiring work (I had planned on renewing internal wires and will probably use cores of Talk3 ofc speaker cable for this seeing as I have 100m handy!) Nothing any more "foo" than this is required.

Finally, I will be building 10 inch tall stands set onto castors. The stands will either appear to be an extension of the speaker base and done in Teak veneered MDF board or veneered Birch ply. They'll be solid and the main speakers will have holes drilled in the base to accept locating rods which will sit in corresponding holes in the stand bases.

I'll update the thread as progress is made but have already had a chat with Lockwoods who were pretty stunned at the find as they've not seen many of these let alone ones in cabs of this quality...it was they who confirmed the rarity and desirability of this pair, so I owe it to the speakers to get them back to better than new condition and will enjoy them for a while before my long suffering wife throws one set of the Tannoys out or throws me out!

 
P

Pac67

Guest
Are you going to re-build the drivers or send them to Lockwoods?
I was going to do the whole lot myself, and have already started by removing and disassembling the drivers. I located the genuine surround kits in Australia and compared the cost of importing the complete kit with having Lockwoods do it. There was hardly anything in it (£25 per driver-ish difference) because they do this day in-day out, they have it down to a fine art, so I may just send them to Nick and the other advantage is that he now uses a jig to get the cones and surrounds exactly plumb when gluing up so voice coil gaps are maintained all the way round as they should be.

It's not too difficult a job though and having removed the cone to clean it up, I think its only an hour or two per cone for me (first time doing it). My thinking however is that with Lockwoods lineage and their world wide reputation, it may pay to get them to do it as it will help with eventual re-sale if I decide at some point to part with them. I'm sure I could do a decent job and do it properly (not just a front glued solution as with many poor DIY jobs done to move the units on....eBay seems to have it's fair share of those so buyer beware!)

From what I've seen, voice coils are good, all measure well (no "Open Loops" and LF/HF units measuring within original factory spec on resistance). So the decision is whether to keep the originals or to run with the improved voice coils/cones for higher power handling (wider range of amps I guess can be used and a larger room space accommodated, not that the ordinary living room will present these beasts with any problems!).

Part of me wants to keep the originals but there are other merits in going the whole hog. I'd then be certain, along with the work that I will do, that these will effectively become as new or better than new. However it pans out, its a good investment. I've located the specs for this driver in this cab now, and along with the bigger 385 version, it promises some very impressive performance.

 

Vinyl Art

Wammer
Wammer
Feb 13, 2010
12,349
185
0
HiFi Trade?
  1. No
Fantastic Paul, and welcome to the wonderful world of Tannoy 12" HPD drivers. You are now a member of a rather exclusive club where having a superior smug look of self satisfaction is actively encouraged:D

Can't wait to see and hear these finished. :^

 
P

Pac67

Guest
Fantastic Paul, and welcome to the wonderful world of Tannoy 12" HPD drivers. You are now a member of a rather exclusive club where having a superior smug look of self satisfaction is actively encouraged:DCan't wait to see and hear these finished. :^
Thanks Bob and smug look now in place ;-)

You'd be more than welcome for a visit/beer/listen when done.

 

graham67

Wammer
Wammer
May 19, 2010
3,776
1,048
158
Hi Paul,

Here are the links for the other pages.

http://www.44bx.com/tannoy/images/Page1.jpg

http://www.44bx.com/tannoy/images/Page2.jpg

http://www.44bx.com/tannoy/images/Page3.jpg

http://www.44bx.com/tannoy/images/Page4.jpg

http://www.44bx.com/tannoy/images/Page5.jpg

http://www.44bx.com/tannoy/images/Page6.jpg

http://www.44bx.com/tannoy/images/Page7.jpg

http://www.44bx.com/tannoy/images/Page8.jpg

I have one of these brochures and even an original price list. The 315 in manfield cabinet cost 93.00 + VAT in October 74. The 315 driver alone cost 60.50 + VAT.

Thanks Graham. That's an interesting link and conforms the studio lineage. Bottom link doesn't work but I'm guessing that was for the 315 drive unit details?
 
P

Pac67

Guest
Many thanks Graham....I'd already found and downloaded the pdf!

Here's a published graph for the frequency response which is still pretty impressive by todays standards and shows that the treble is actually pretty extended and doesn't roll off above 10 to 14KHz putting to bed some urban myths about these drivers:

Page8.jpg


 

speedysteve

Wammer
Wammer
Dec 25, 2007
3,254
39
93
HiFi Trade?
  1. No
A nice pair.

I re-foamed my 15" 3828 - not a bad job. Interesting that Lockwoods will do just the surrounds. They wanted and I assume usually want to do a whole re-cone as its much less time consuming for them. If they will do it for little more then the price of landed surrounds - great!

 
P

Pac67

Guest
A nice pair.I re-foamed my 15" 3828 - not a bad job. Interesting that Lockwoods will do just the surrounds. They wanted and I assume usually want to do a whole re-cone as its much less time consuming for them. If they will do it for little more then the price of landed surrounds - great!
Hi Steve

pricing up just the surround kit (dustcap and glues included) it's not much more for Lockwoods to re-foam. The best kits work out at £110 per pair. Lockwoods charge £160 per pair to re-foam using these kits. A complete re-build including new cones, improved surrounds, new (improved power handling) voicecoils and rear suspension, including dustcaps etc is £240 per pair inclusive of all work/VAT etc. These kits are meant to bring the HPD up to a higher power handling equivalent of the Monitor Golds (same chassis, magnets etc as the MGs). If the speakers are keepers, part of me thinks its worth the expenditure to get the whole thing done professionally as not only should that be good for more than the 15 years that foam surrounds might give, it should improve performance and if I decide to sell on will definitely help resale value.

I've already stripped the drivers down and started removing the foam. Doesn't look to be too bad a DIY job to finish them but once you've added up glues, pressurised air can spray (cleaning out voice coil gaps), meths, a couple of cut down artists paint brushes and the kit, then compare it with Lockwoods charges, its a no brainer to package them up because the extra spent will be recouped come potential sale time. ("DIY" rebuild could have the opposite effect no matter how well its been done). Were I certain that these were keepers, I'd do everything myself.

As it stands, all wiring work, new binding posts, cabinet work and custom stands will be the work of my own fair hands. :geek:

 

paulf-2007

Wammer
Wammer
Jun 18, 2008
4,426
103
108
souf east for work
HiFi Trade?
  1. No
Paul what makes you say they are infinite baffle? I believed infinite baffle is where the driver is mounted in a wall with back of the driver in a different room or chamber. looks like a nice project btw.

 
P

Pac67

Guest
Paul what makes you say they are infinite baffle? I believed infinite baffle is where the driver is mounted in a wall with back of the driver in a different room or chamber. looks like a nice project btw.
Infinite Baffle is also a generic term used for any sized sealed enclosure Paul (sealed enclosures preventing the interaction of forward and rear woofer radiation at low frequencies just like true infinite baffle designs on a larger scale), but you get the gist; they're non-ported. Measured the volume today and they work out at roughly 110 litres internally so a little larger than the Turnberrys 100 litre enclosures. Ideal for the 12 inch in ported cabs is said to be between 130 and 150 litres, so it will be interesting to hear what sealed cabs of this size sound like.

 

speedysteve

Wammer
Wammer
Dec 25, 2007
3,254
39
93
HiFi Trade?
  1. No
Jeez - those Aus repair kits have gone up then!

BTW HPDs are higher power handling than Golds - at least 15" ones are - I have less experience of 12". The HPDs prob have the spiders glued on the rear of the cones - this helped with cone break up. Again the 15 do - Golds did not.

Again for 15" ones, whether they are the same chassis as Golds depends on age. The older HPDs have the same basket. 'Newer' ones only 4 mounting holes.

As you can prob tell I had a thing for 15" ones a while ago. I've played with 3828's, Golds, Reds, HPD and CPA's. Never seen a pair of Silvers or Blacks though:)

Hi Stevepricing up just the surround kit (dustcap and glues included) it's not much more for Lockwoods to re-foam. The best kits work out at £110 per pair. Lockwoods charge £160 per pair to re-foam using these kits. A complete re-build including new cones, improved surrounds, new (improved power handling) voicecoils and rear suspension, including dustcaps etc is £240 per pair inclusive of all work/VAT etc. These kits are meant to bring the HPD up to a higher power handling equivalent of the Monitor Golds (same chassis, magnets etc as the MGs). If the speakers are keepers, part of me thinks its worth the expenditure to get the whole thing done professionally as not only should that be good for more than the 15 years that foam surrounds might give, it should improve performance and if I decide to sell on will definitely help resale value.

I've already stripped the drivers down and started removing the foam. Doesn't look to be too bad a DIY job to finish them but once you've added up glues, pressurised air can spray (cleaning out voice coil gaps), meths, a couple of cut down artists paint brushes and the kit, then compare it with Lockwoods charges, its a no brainer to package them up because the extra spent will be recouped come potential sale time. ("DIY" rebuild could have the opposite effect no matter how well its been done). Were I certain that these were keepers, I'd do everything myself.

As it stands, all wiring work, new binding posts, cabinet work and custom stands will be the work of my own fair hands. :geek:
 
P

Pac67

Guest
Jeez - those Aus repair kits have gone up then!BTW HPDs are higher power handling than Golds - at least 15" ones are - I have less experience of 12". The HPDs prob have the spiders glued on the rear of the cones - this helped with cone break up. Again the 15 do - Golds did not.

Again for 15" ones, whether they are the same chassis as Golds depends on age. The older HPDs have the same basket. 'Newer' ones only 4 mounting holes.

As you can prob tell I had a thing for 15" ones a while ago. I've played with 3828's, Golds, Reds, HPD and CPA's. Never seen a pair of Silvers or Blacks though:)
Yes, the 12 inch 315 HPD's are 65 watts as standard. Don't know what increase or difference that the complete Lockwood kit brings, but they claim performance improvements (including power handling). Because mine had apparently been effectively run without surrounds for a while ( :doh: ) Lockwood reckoned that the suspension could be damaged. Looks ok but its not a king's ransom so may as well go the whole hog with them. Mine are from 1974 so probably classify as the "newer ones" (4 mounting holes).

Ironically I once turned down a smallish corner cabinet (deep mahogany finish) fitted with a 12 inch Red. Could have had it for £150 at the time. You live and learn.

 

deggie

Wammer
Wammer
Feb 12, 2011
7,349
3,488
158
edge of birmingham
AKA
keith
HiFi Trade?
  1. Yes
Paul , if they have been run without surrounds, a high possibility of damage, have them stripped back and rebuilt, my 12 hpd were in fine condition, i wish i had kept them

now.... hendrix never sounded better....treat them as bygone treasures... love em, care for them , its money in the bank, with a better interest rate.... they will give the

turnberrys a run, ..................you,ll have some fun comparing them.

 
P

Pac67

Guest
Paul , if they have been run without surrounds, a high possibility of damage, have them stripped back and rebuilt, my 12 hpd were in fine condition, i wish i had kept themnow.... hendrix never sounded better....treat them as bygone treasures... love em, care for them , its money in the bank, with a better interest rate.... they will give the

turnberrys a run, ..................you,ll have some fun comparing them.
My conclusions too Keith. Really looking forward to getting them running but won't be cutting any corners in making them the best examples I can.

 

Latest posts

Forum statistics

Threads
113,444
Messages
2,451,263
Members
70,783
Latest member
reg66

Latest Articles