The biggest debate in the history of humankind -Tannoy crossovers original vs new.

[Edward]

Denzil

Been reading your posts about your cab build and most impressed. Hopefully you can get hold of a calibrated mic and run some tests and then optimise things.

In terms of crossovers, I have Berkeleys (15 inch HPDs) and had the crossovers restored by Paul C and he kindly did a walk-through of the process he followed when restoring mine. (links below). The improvement I heard was immense and totally worthwhile.

To the best of my knowledge Paul does not provide the roll-off and energy switches on his custom external crossovers. I believe there are some 3rd party crossovers available which mimic what the original Tannoy autoformers do. Not tried them myself but reviews are mixed.

Anyway - the links.


Part 1

Part 2

Part 3

[WESTLOWER]

Denzil

Been reading your posts about your cab build and most impressed. Hopefully you can get hold of a calibrated mic and run some tests and then optimise things.

In terms of crossovers, I have Berkeleys (15 inch HPDs) and had the crossovers restored by Paul C and he kindly did a walk-through of the process he followed when restoring mine. (links below). The improvement I heard was immense and totally worthwhile.

To the best of my knowledge Paul does not provide the roll-off and energy switches on his custom external crossovers. I believe there are some 3rd party crossovers available which mimic what the original Tannoy autoformers do. Not tried them myself but reviews are mixed.

Anyway - the links.


Part 1

Part 2

Part 3

Ahhh welcome back lord Lucan!!

[Denzil]

Denzil

Been reading your posts about your cab build and most impressed. Hopefully you can get hold of a calibrated mic and run some tests and then optimise things.

In terms of crossovers, I have Berkeleys (15 inch HPDs) and had the crossovers restored by Paul C and he kindly did a walk-through of the process he followed when restoring mine. (links below). The improvement I heard was immense and totally worthwhile.

To the best of my knowledge Paul does not provide the roll-off and energy switches on his custom external crossovers. I believe there are some 3rd party crossovers available which mimic what the original Tannoy autoformers do. Not tried them myself but reviews are mixed.

Anyway - the links.


Part 1

Part 2

Part 3

Thanks so much Edward !!!

This is extremely helpful information.

Regards,

Denzil

[fatmarley]

Just had a quick look at the Monitor Gold circuit diagram. If the shunt capacitors (16uf and 3.3uf) are electrolytic then replacing them with film will change the frequency response because of the difference in ESR. The capacitors in series with the tweeter will most likely be ok to replace with film (maybe they are already?) because of the treble adjustment controls.

Does anyone know what caps are electrolytic?

http://www.44bx.com/tannoy/images/Mo...ld12_15xO1.gif

[Denzil]

Denzil

Been reading your posts about your cab build and most impressed. Hopefully you can get hold of a calibrated mic and run some tests and then optimise things.

In terms of crossovers, I have Berkeleys (15 inch HPDs) and had the crossovers restored by Paul C and he kindly did a walk-through of the process he followed when restoring mine. (links below). The improvement I heard was immense and totally worthwhile.

To the best of my knowledge Paul does not provide the roll-off and energy switches on his custom external crossovers. I believe there are some 3rd party crossovers available which mimic what the original Tannoy autoformers do. Not tried them myself but reviews are mixed.

Anyway - the links.


Part 1

Part 2

Part 3

Thanks again Edward !

I'm sorry I somehow missed your message earlier.

My cabinet design was more a labor of love than some audio project although I'm getting more and more interested in audio now.

I've gone through everything properly now and Paul's work looks amazing ! Hopefully I will get a mic and do some tests post Covid 19. Did Paul suggest restoring your crossovers ? Or was that your decision ? Did you discuss with him the pros and cons of new vs restored crossovers ?

Regards,

Denzil

[Denzil]

Ahhh welcome back lord Lucan!!

Thanks !

Missed this earlier !

Regards,

Denzil

[sailor]

Hi Denzil,

To answer your question : to refurbish or replace with new, is simple, it depends

It depends on who will do the refurbishing and which new XO you would be considering.

One thing is for sure, they definitely need upgrading. If you refurbish you need some considerable experience with the different components and the effect they individually have on the sound. You do of course get to choose.

Having designed and built many speakers I know the time and effort you have invested in the impressive ones you have built and were it me, I would not hesitate to spend generously. The Tannoys deserve it.


If you buy you may get what the seller considers 'good enough'. I see Paul from RFC has been mentioned a few times and though I know nothing about this gentleman am sure he could advise you and use any component of your choice, should you have some specific item in mind.

I looked at the links you provided and at his board layout and it would not be too difficult for him to adapt it to accommodate a huge cap to the tweeter for example.


I see another poster is warning you about a cap's ESR
He claims replacing an electrolytic with the same value film cap will change the frequency response. This is simply not true.

A different value cap will alter the response but we are not considering doing that. The formula for Capacitive Reactance Xc = 1/2Pi.fc There is no value for R in the equation, so it is apparent that resistance can be ignored. Also consider that were this not true then every time you selected a different tweeter setting you would be changing the XO frequency.

Here is a link to a thread that I think will interest you. I have some pics showing an XO I built using a 6.8uf Jantzen Superior capacitor which is the same value used in the Tannoy gold. Its the big fat red one. The units I built for myself and friends used a mixture of Clarity Cap, Mundorf Supreme and Jupiter wax caps. I could not afford the very expensive Jupiters but maybe you can. They are delicious. The wire connecting to the speakers is the same Duelund I recommended you consider in your current speaker cable thread.

In my post 117 on page 12 there is a link that will take you to an excellent, almost a dissertation, on the sound of different caps and has been recently updated.

https://theartofsound.net/forum/show...efurb-s/page12

If you read on a few more pages you will find more pertinent info.

The link I provided on your speaker wire thread is a review by Jeff Day on the Duelund wire that he uses on his Altec VOTT and Tannoy Westminsters, I think. You can find a detailed discussion on his crossovers for both designs where he uses the eye-wateringly expensive Duelund caps. An entertaining read.

[Edward]

Thanks again Edward !

I'm sorry I somehow missed your message earlier.

My cabinet design was more a labor of love than some audio project although I'm getting more and more interested in audio now.

I've gone through everything properly now and Paul's work looks amazing ! Hopefully I will get a mic and do some tests post Covid 19. Did Paul suggest restoring your crossovers ? Or was that your decision ? Did you discuss with him the pros and cons of new vs restored crossovers ?

Regards,

Denzil

Yes Paul and I did discuss this but I decided mainly for cost reasons for now just to go for a restore of the original xovers. Paul said that a restore would get me mostly there. I do have experience (friend's systems) of Paul's external xovers (driving resp. 12 inch HPDs and 12 inch Golds) and they make nice sounds. But of course their systems are different to mine as well as their room acoustics so can't compare like for like.

I have in mind (probably more a dream) of commissioning cabs for my HPD385s and Paul's external crossovers would be part of that plan (dream) hence my interest in your cabs. BTW which design did you use? Was it one from hilberink?

atb
Edward

[fatmarley]

I see another poster is warning you about a cap's ESR
He claims replacing an electrolytic with the same value film cap will change the frequency response. This is simply not true.

Well, I'm sat here now in front of LspCAD 6 pro, changing the ESR values of the shunt capacitors and the frequency response is changing (these are my current diy speakers). I could go one step further and get my measurement microphone out to measure the actual frequency response, but I don't see the point because my model is accurate.

[Barry]

Of course changing the ESR value will change the frequency response. Just do the maths: changing the ESR will change the Q-value for the capacitor, and of the circuit, just as changing the self resistance of the inductors will change the circuit Q. The roll-over frequency of the filter is affected by the Q-value, though the effect is relatively small.