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Tannoys always full of surprises...

Tony L said:
Looking at the eBay listing for a version of the Mainly Tannoy crossovers (link) it does appear that the level and roll off settings can be altered. If these crossovers in any way mimic the original ones I’d certainly try level -1 and roll-off -1 just to see if it is a simple level thing. Certainly every third party crossover I have heard to date has sounded too bright, and the advert for these actually claims it makes them ‘tighter and brighter’, which may well not be what you actually want.

PS The reason I use Tannoys is I love the way they sound, I don’t want them altered! (Mine are totally stock with level and roll-of in their ‘level’ position, though my amplification is a bit on the warm side, I’d likely alter the settings back a bit with modern solid state).
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Yep they are a newer version.The ones I had on were fixed. I didn’t feel they were too bright it was just the issue with that upper midrange. I could take the autoformers off the Troels ones I have made and construct original. But that will be a last resort after I have checked out drivers/tightness of bolts etc. I don’t use the plugs. The LF wired direct soldered and the HF section connected via a screw connection fixed to basket. I’m fairly convinced something relating to drivers given the cones were so wrong. Will document the strip down and see what I find.
 
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cooky1257 said:
Heres what Troels describes as the correct wiring shown in red.
49013897901_16fbe8f23d.jpg

But look at his final/finished graph,
49013899236_b3438c0e62.jpg

it's the same as the blue, ahem 'incorrect' wiring curve shown in the first..
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Is that the inverted tweeter polarity graph ? Things were complicated by the misunderstanding regarding the bass inductor value.
 
Just in, some tired 12" HPD Mansfields for refoam. Cabs aren't too bad, driver frames are early ones with slots for the mounting bolts, horn throats look really roughly machined and are rusty. Will record progress as I go.
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Elephantears said:
I'm not sure if this is acting as an all purpose Tannoy thread, or specific to cooky's work. If the former, I just thought I'd mention that there is absolutely no doubt in my house that 10" HPDs like a 4 Ohm tap (at least on a Primaluna Dialogue Premium).
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I totally disagree. My 10" HPD much prefer the 8 Ohm tap (this week).
 
Hooch500 said:
Perfect timing ! Was just looking for a documented strip down on net
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Don't hold your breath! There's plenty online/ here/ Hans' site.
Whatever you do needs to be reversible( or it'll cost you more than a few bob) e.g. The cone surround should be held in place by the frame clamps around the circumference but if the edge has been glued down too you may not be able to remove it without damage.
 
Don't store Tannoys in the shed/garage.....Grim, really grim.I thought these horns were stainless steel.....

49023627012_4628807ab7_c.jpg
 
Finished; HF fettled, refoamed, LF and HF VC gaps cleaned(quite a sod of a job in this case), serviced and FR matched as close as was/is possible.
A before and after....
49030598738_4df36a0b5d_z.jpg


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Drivers unmounted so just for HF;
49031272032_d4e6ab7617.jpg

49031272727_ed907a352e.jpg


Now ready for another 20 years of sounding great.
 
Hooch500 said:
Wow they were a mess. Was that paint and rust on the horns throats ?
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Not paint just corrosion(rust and powdery white stuff) caused by endless cycles of morning dew probably when in storage.
Rusty mounting bolts are a dead give-away of potential trouble ahead-thankfully in this case no 'green coil' which would've been game over.
 
Horns have a smoother dispersion if they have a slightly rough surface, but yes that set may take it a bit far!!!
 
Tony L said:
Another thing to consider/experiment with is how tightly you have the drive units bolted to the baffle. If you are using a traditional thin-wall Tannoy-style cabinet, i.e. with the drive units mounted from the back to a rather thin baffle over tightening them sounds absolutely horrible and does really mess up the treble/make them over-bright/forward. I have mine with plastic washers under the bolts on the back and just very gently nipped-up so they can’t move, little beyond finger-tight. My guess is this allows the thick rubber front gasket to add some damping to the baffle rather than the metal basket directly coupling and energising it, but whatever the reason it sounds hugely, hugely worse tightened up too hard. This has proven true both with my previous DIY York cabs and my current Lockwoods. Certainly play with this.
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Big thanks for this tip Tony. I have 15” HPDs in Lockwood Academy cabinets which I have always felt were on the edge of being too forward sounding, monitor-like, more as a consequence of lacking truly deep bass. The drivers are rear mounted onto studs with wing nuts. I suppose the wing nuts should have been a clue but after a lifetime of making off heavy electrical connections I tend to over tighten things so always gave the wing nuts a final nip-up with an adjustable spanner just to be sure. I mistakenly thought this would improve the sound, wrong! Having slacked them and re-tightened to finger tight the bottom end has filled out and soundstage depth and imaging have improved even further.

From Personal experience HPD crossovers are definitely held back in regard to soundstaging and imaging if they’re still on their original capacitors. Tonally they’re grand though. I have Clarity Cap ESA in mine, except for the 3.3uf in parallel with the HF which is a Mundorf Evo oil. With these in place their ability to put someone in the room can be spooky. I’ve tried fancier Mundorfs but I find this combo good all round compromise. Definitely subject to change though!
 
Johnjo said:
Big thanks for this tip Tony. I have 15” HPDs in Lockwood Academy cabinets which I have always felt were on the edge of being too forward sounding, monitor-like, more as a consequence of lacking truly deep bass.
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After years of brainwashing by the Linn/Naim thing of the ‘80s I had my whole perception changed by having a half hour or so chat to the late Tom Fletcher (Nottingham Analogue) at a hi-fi show back in the ‘90s. Tom’s view was that ‘tight’ is almost always wrong as the very last thing you want to do is to make things behave like a tuned structure/drum/bell. His setup instructions for his turntables was “tight enough to stop it falling apart, but no more”. After that I started experimenting a lot with all bolt tension in my system and now pretty much everything is following this mindset. I really do tune every bolt tightness by ear now! Some do like to be tight, eg. the main bearing to chassis in my TD-124, but most others (arm board, arm to arm board, arm VTA etc) don’t. For speakers I am convinced the reason I tend to prefer BBC or Lockwood boxes to other boxes is that they have screwed baffles and back doors, which really stops the cabinet behaving like a conga drum as long as they are not overtightened. It took me a long time to really get my 15” Golds to sing in my Lockwood cabs and I advise you to play with the back door bolts too. I don’t use a spanner here, I just nip them up with my fingers. There are so many of them they hold the back door on perfectly with very little tension and I just get a very dull ‘thud’ when rapping the cabs, no note pitch at all (i.e. exactly what you want).

PS Stereophile’s Art Dudley has picked up on this now (I’m sure not from Tom F or me) and made the point a couple of months ago that his 301 sounded awful after he’d tightened up its mounting to the plinth and improved hugely once he went around applying a far lighter tension to bolts. IME you want things at the exact point they are held solidly, but before they start to behave as a tuned/pitched structure. That is actually quite a precise point so takes a little fiddling to hit.
 
Good point about the back doors. Will give that a try along with the drive unit nuts. I have a self made Lenco with a 30KG plinth, triple platter and separate arm board, maybe some experimentation here with tightness of various bolts, screws too. Costs nowt !
 
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