Overhaul 12" tannoy monitor gold's.

[cooky1257]

So the MG15's natural HF roll-off begins around 2kHz, and presumably a little higher than that for the MG12? So surely running the LF cone with no LPF such as the Silver XO would cause a noticeable broad bump in the response above 1kHz or 1.5kHz? (I always forget if the Gold's XO frequency is 1kHz or 1.5kHz!).

That's my thinking too then factor in the horn resonance peak at 3khz...the broad hump may be ameliorated somewhat by inverting HF polarity to 'exploit' a phase cancellation but tbh given the rarity of Silver xovers, the now unobtainium nature of replacement HF dias what's the point? I remember my eager anticipation of getting to hear some Reds years ago and was taken aback by the R3 sound of applause through them-basically frozen peas down a drainpipe-that's the un-notched honk right there, though I didn't know at the time.

 

[Tony L]

12” & 15” Gold have a 1kHz crossover, though the 10” 3LZ is higher up, can’t remember what though. Makes sense as the smaller driver will be good to a higher freq.

 

[cooky1257]

Never say never with vintage gear, if it works for you then that's what's important.
JBL 4350 has drivers spread all over its baffle-it shouldn't sound good-they sound absolutely incredible(to quote GT " no one told the 4350 it shouldn't sound good").

 

[ToTo Man]

Having never heard a Silver or Red, to me it would be interesting to compare the Silver XO vs Red XO vs Gold XO using digital EQ* on the Silver and Red XOs to ameliorate the respective peaks from LF/HF overlap and the 3kHz honk, to see which XO comes out on top in terms of coherence, musicality and transparency. I'm aware there are those who'd suggest aftermarket crossovers are the way to go, or even an all-active system, but I suspect this throws the baby out with the bathwater and strays too far away from the Tannoy sound, at least based on my limited experience with an aftermarket MG crossover from a well-known Tannoy reseller. (I'll look for the frequency response measurement I took of said crossover so stay tuned!).

* I can feel the analogue purists shuddering in horror at the very thought!

 

[ToTo Man]

Here's a comparison of the stock LSU MG12/15 crossover and aftermarket "A-Series" crossover I tried. Something funky is clearly going on between 1kHz and 2kHz in the aftermarket crossover!:

 

[cooky1257]

Having never heard a Silver or Red, to me it would be interesting to compare the Silver XO vs Red XO vs Gold XO using digital EQ* on the Silver and Red XOs to ameliorate the respective peaks from LF/HF overlap and the 3kHz honk, to see which XO comes out on top in terms of coherence, musicality and transparency. I'm aware there are those who'd suggest aftermarket crossovers are the way to go, or even an all-active system, but I suspect this throws the baby out with the bathwater and strays too far away from the Tannoy sound, at least based on my limited experience with an aftermarket MG crossover from a well-known Tannoy reseller. (I'll look for the frequency response measurement I took of said crossover so stay tuned!).

* I can feel the analogue purists shuddering in horror at the very thought!

You could probably blend the LF/HF in any number of ways to produce a flat(ish) response but the character of that blend is where the art of 'voicing' comes into play and is one of the reasons why I shun the after market guys' offerings as not authentic unless they reproduce the originals to the very letter-furthermore dropping new AM crossovers onto old/aged units is a crap shoot unless the crossovers are bespoke for those particular drivers and reflect their current measurement/spec.....

 

[Jhon]

Hi everyone who is contributing to this thread. I'm impressed by the range of help, advice, opinion that's been expressed so far so collectively a very big thank you to you all. I'm posting briefly today to say that I'm still in Wales and struggling with connections but I will pitch in and make replies and further queries later this week. I wouldn't want anyone to think I was a rude bugger who just ignored stuff? But whilst I'm here the thought crossed my mind that in very loosely similar custom forums - I'm thinking cars and bikes and w.h.y. there are physical events where folk collect , demonstrate and share their efforts. Is there Anything similar in the loudspeaker world ?

 

[Jhon]

Before getting into external/bespoke crossovers(debatable) any 'overhaul' should start with the drivers.
Measure them, if they are poorly matched or displaying an uneven response through the hf range significant improvements can be gained by correctly re-installing the HF diaphragms.

Transfer function of Silver(green) vs Gold(blue) crossovers showing the gold's 2nd order slope, notch filter and HF gain adjustment ;

Thanks for the graph .it seems to confirm ff1d1l what has to say in so much as to smooths the response curves. Did any one else use silver xovers with gold's. And thanks to for the suggestion to have the gold's checked but by whom and at what sort of cost?

 

[Jhon]

Before finding my large Lockwood cabs I was very seriously considering commissioning a pair of Onken cabs. IIRC they actually make far more sense with the rubber or foam surround Tannoys which kind of put me off (mine are 15” Golds, so hard surround). I’d certainly look into this if I had a pair of rubber-surround 12” Golds. I suspect they might be a very good solution. There are sites somewhere with the necessary math to calculate the cabinet and vent sizes etc.

Thanks Tony I have to confess onken cabs are new to me . Did any one actually try it it would be good to hear from them and who would make then. It seems there are a few measurable parameters to take into account in designing an onken. My only measuring equipment is my ears! So I would prefer a manufactured version by someone who has experience and development cos I would fear that getting some dimension or another a bit wrong would negate the benefits of onkens. I do have reasonable facilities and help to build cabs but need sharp information to work from

 

[Jhon]

Hard edge 12" Gold Fs is 49hz(if you are lucky), any reflex cab above say 100L is pretty pointless unless you like to increase the 'peak' of the tuning bump.
If they are 12R's then 130L tuned to 28hz is pretty much the sweet spot in terms of size/performance.

12R/15" Golds are much closer in terms of Fs/Qts/VAS/Cms/Mms to the foam edge models hence the interchangeability of HPD's and Golds into boxes such as Amesbury/York/Ardens/Lockwoods.

I just run some sims of a 12R in Onken cab, 330L, 6x rectangular 50x280x450(l)ports, 3 along each side. Shocking 47ms group delay near 31hz tuning that drops to a fine 12ms @40hz. Port air speed is very low @3m/s, bass shelf as is normally par for course with these drivers not tuned maximally flat is virtually absent-1dB and the tuning peak is around +2.5dB in the sim but would expect the aspect ratio of the port /extra surface area drag would damp that to be essentially flat. Huge but interesting.

 

[Jhon]

Thanks cooky. I have to confess that the world of tannoy DC s is more diverse than I knew. does 12r = reds or does it refer to surrounds? How do you tell which surrounds you have? Sorry if this sounds a stupid question but I'm stupid . Otherwise I appreciated your direct observation of 130l cabs tuned to 28 herz. But are my gold's right for it ?

 

[cooky1257]

Thanks for the graph .it seems to confirm ff1d1l what has to say in so much as to smooths the response curves. Did any one else use silver xovers with gold's. And thanks to for the suggestion to have the gold's checked but by whom and at what sort of cost?

No, quite the opposite, the graph shows the crossover transfer function or ‘equalisation’ applied to the raw driver responses.

12R refers to the rubber surround( obvious just by looking) version which has a much deeper bass response than the hard edge version. The 28hz/130L is for the 12R driver.

 

[Jhon]

Sorry, just seen this.
They just sound, to my ears, far better.
They run the bass cone wide open, the crossover for the pressure driver is simpler, uses no level controls and is of higher quality components.
Makes for a smoother, but much more present and open sound. And the butyl surrounds allow the cone to go deeper.
Anyone tried Red crossovers on 15" Golds or HPDs, out of interest?

Thanks I appreciate your comment . I can relate to how you descrbe what you're hearing . I did come across a previous post of yours in which you were describing building cabs and the result you got which I also liked but lost track of it. Can you point me back to it?

 

[Jhon]

I tried this after reading LesW's and MrTibbs views on it. I couldn't quite believe the effect it had. A few pfm members have reported similar. Nobody can come up with a technical reason why it brought the improvements experienced by myself and others.

Just be careful not to get any inductors too near a transformer or you will have plenty of hummmmmmm.

Thanks for picking this up What was the effect?

 

[Jhon]

No, quite the opposite, the graph shows the crossover transfer function or ‘equalisation’ applied to the raw driver responses.

12R refers to the rubber surround( obvious just by looking) version which has a much deeper bass response than the hard edge version. The 28hz/130L is for the 12R driver.

Appreciate that thanks

 

[ff1d1l]

Thanks I appreciate your comment . I can relate to how you descrbe what you're hearing . I did come across a previous post of yours in which you were describing building cabs and the result you got which I also liked but lost track of it. Can you point me back to it?

https://pinkfishmedia.net/forum/threads/jbl-4430-build.225699/
it wasn't Tannoys, was JBL 4430 clones.

 

[cooky1257]

Some 130L/28hz/12R.
https://pinkfishmedia.net/forum/threads/tannoys-always-full-of-surprises.215692/page-3

 

[mega lord]

Thanks for picking this up What was the effect?

Have a read of this thread https://pinkfishmedia.net/forum/threads/amp-crossover-speaker-connection-quiz.18915/

 

[Jhon]

https://pinkfishmedia.net/forum/threads/jbl-4430-build.225699/
it wasn't Tannoys, was JBL 4430 clones.

Thanks your jbl's look fabulous but the thread i picked up was different- it involved blinding a bitumen coat to the interiors with sand and casting plaster of Paris over that.

Have a read of this thread https://pinkfishmedia.net/forum/threads/amp-crossover-speaker-connection-quiz.18915/

Have a read of this thread https://pinkfishmedia.net/forum/threads/amp-crossover-speaker-connection-quiz.18915/

Have a read of this thread https://pinkfishmedia.net/forum/threads/amp-crossover-speaker-connection-quiz.18915/

https://pinkfishmedia.net/forum/threads/jbl-4430-build.225699/
it wasn't Tannoys, was JBL 4430 clones.

 

[Jhon]

Thanks your jbl's look fabulous but the thread i picked up was different- it involved blinding a bitumen coat to the interiors with sand and casting plaster of Paris over that.

Have a read of this thread https://pinkfishmedia.net/forum/threads/amp-crossover-speaker-connection-quiz.18915/

Thanks that is handy and confirmatory. And it seems the way to go with new cabs