Apr 172013

The energy & excitement behind the Duelund-WRSE Project is really ramping up and I’m thrilled about all of you who are joining in to do your own Tannoy loudspeakers project at the same time! I will document every step of the project here at Jeff’s Place so everyone will have real-time information flow, and I will be writing up the results of the Duelund-WRSE Project as a full reference-quality article for publication at Positive Feedback Online so those who can’t participate right now will be able to duplicate the results of the project in the future.

Westminster Royal

I just got a note from Frederik Carøe (Duelund Coherent Audio in Denmark) telling me that this project has inspired him to produce a new product – a 200 uF Duelund capacitor to use in the low-frequency portion of the WRSE crossover: “We’re going to do some custom new product 200uF for you, for the sake of completeness … You can start without them , we’ll ship them next week.”

I want to thank Frederik Carøe again for providing the Duelund components for this project, and I’m really excited to hear about the new capacitor that he is developing for the low-frequency crossover part of the project. I really appreciate it, and the project would have been impossible for me without Frederik’s involvement. Thank you Frederik!

Duelund XO components 11

There has been another exciting development for the Duelund-WRSE Project this morning: Mark Coles of Sablon Audio in London, who has also been advising me on this project about wires and connectors, and makes the wonderful Panatela component speaker cables that I reviewed in Issue 63 of Positive Feedback Online, has told me he wants to donate some custom made Panatela cable runs to go from the WRSE drivers to the outboard crossover. Once again I am completely blown away! Thank you Mark!

Long time Tannoy enthusiast Frank Rodgers also uses the Panatela component speaker cables for his Westminster Royal SEs, and he has asked Mark to make him another pair to serve as the internal wiring from speaker drivers to external crossover too. The idea is to connect the wiring harness Mark is making directly to the speaker driver’s connecting wires so there’s no degradation from the stock Tannoy internal connectors, or tag blocks, and then connecting it directly to the external crossover at the other end. A totally purist approach that minimizes signal degradation. If you’re interested in doing the same thing with your Tannoys you can email Mark Coles about making you a wiring harness too.

Panatela speaker cables on Kingdom Royal

Here’s what I’m thinking of for a path forward for the Duelund-WRSE Project:

1. Determine what remaining supplies need to be ordered for the project (this weekend). On the shopping list are Neotech hookup wire in teflon and WBT crimp sleeves to connect wires. (Mark Coles tells me the WBT crimp sleeves sound better than solder connections made with leaded WBT silver solder, so we’ll use the WBT crimp sleeves wherever we can).

2. Do a basic layout of the low & high-frequency sections of the crossover (this weekend).

3. Burn everything in with the Cable Cooker (over the next week or two). I talked to Alan Kafton about using his Cable Cooker device to precondition the components and wires used in the project to minimize the run-in time. Alan has provided me some guidance which I’ll provide more details about in a future post.

4. Remove the low & high-frequency boards from the Westminster Royal SEs and determine the length of internal/external wiring required to reach the crossover from the speaker driver.

5. Bypass the WRSE high-frequency controls.

6. Temporarily setup the stock crossovers as external crossovers as the rest of the components and wires are being conditioned on the Cable Cooker (next weekend).

7. Finalize layout of the conditioned components.

8. Build a final exterior crossover chassis. (I am thinking of something similar to the Acoustic Revive quartz isolation platforms for a chassis for the crossovers).

9. Take care of any remaining details.

Those are my thoughts for the path forward off the top of my head. Each step listed (and the ones I have no doubt forgot to add) will be fully described as we go along.

Here’s some more photos:

Duelund XO 1

Duelund XO 2

Duelund XO 3

Duelund XO 6

Thanks for stopping by!

 Posted by at 9:56 am

  19 Responses to “The Duelund-WRSE Project: The Path Forward”

  1. “Temporarily setup the stock crossovers as external crossovers as the rest of the components and wires are being conditioned on the Cable Cooker (next weekend).”

    Jeff, you will not be able to remove the HF stock crossover and use it externally because the board on which the HF crossover it is set, it seals the speaker cabinet.

    Unless you find a way to seal the cabinet temporarily.

    I am using for the moment the stock crossovers externally because I have a spare set.

    For the LF crossovers though, is not a problem to be placed externally as they are placed internally at the back inside the cabinet and out of the horn loading system of the cabinet.

    • Hi Pambos,

      Thanks for the heads up – appreciated.

      So did you leave the stock high-frequency crossover in place in the cabinet and just disconnect it from the circuit? Or did you install something special to seal the cabinet and remove it?

      Also, did you leave the stock low-frequency crossover in place and just bypass it when using an external crossover?

      I’ll try to take detailed photos as we proceed so it is clear for others exactly what can – and can’t – be done.



  2. Hi Jeff,

    The only component that you need from the stock crossover is the Autoformer.

    All the rest you have got them from Duelund ( you are waiting only the 200uF to be sent)

    So only thing you do is disconnect the stock crossover and the wires from the drivers go directly on the speaker binding posts.

    That is what I did.

    You don’t need to remove either the HF or the LF crossover from its place.

    • Hi Pambos,

      I ordered a pair of Vishay 1R0 RHC50 thick film resistors, and Paul is sending a pair of autoformers, so I will have everything I need for the low & high-frequency crossover circuits and will not need to take anything off the stock crossovers.

      Frederik let me know a few minutes ago that the 200 uF CAST Mylar capacitor is almost ready, and should be shipping tomorrow. When it gets here I’ll do a blog post about it with some photos.



  3. Hi Jeff,


    Anyone who is going for an external crossover should do the same. This way the stock crossover will stay untouched and can be connected to the signal any time for comparisons!

    What you need the Vishay resistor for??

    Didn’t you get the 1R0 resistor from Duelund? Duelund resistors are much better than Vishay.

    • Hi Pambos,

      Frederik doesn’t make a 1R0 resistor for his Duelund line, so he told me to go ahead and use the stock resistor in the low-frequency part of the crossover, which is a Vishay 1R0 RHC50 thick film resistor.



  4. Correction,

    We do make 1R, I was just worried about the power requirements, in this application. According to Pambos, there has been no problems.

  5. I am using the Duelund 1R resistor on the outboard crossover for 4 years now.

    There has been NO problems at all, and the sound is magical.

    You should know though that my power amp is a single ended Audio Note 22 Watts.

    Some of you who are using bigger output amps may better chose higher rated resistors. It is a compromise though, because none is as good sounding as Duelund.

    According to the resistor review ( http://www.duelundaudio.com/downloads/Resistorsvol5no3HIFICriticHiRes.pdf ) a very good choice would be the Mundorf SUPREME. Vishay scored very poorly.

    AND I wouldn’t use the Vishay if I had a bigger output amp, mainly because it needs the cooler (same one as it is on the stock crossover) and the cooler takes a lot of space. Why waste space when there are better resistors which take almost no space?

    • I have been using the ASR Emitter II Exclusive Version Blue amplifier during the review period, which is 250 watts into 8 Ohms, but it is being returned and I will go back to using my 9 watt 300B amplifiers.

      Pete Riggle, who used to have a loudspeaker manufacturing business, and has designed a number of loudspeaker crossovers, also thought that a 10 watt rated resistor would be fine in all positions in the crossover.

      Tannoy did specify 50 watt resistors for all the resistors in the circuit diagram for the crossover, but it doesn’t appear that more than 10 watts will be needed in this sort of design application (according to Pete).

      According to your experience, Pambos, it seems like the 10 watt rated resistors should work just fine.



  6. Hi Jeff,

    10 watt is fine. The 1R though from Duelund is only 5 watts and because it is used on the woofer crossover Frederik wanted to be on the safe side..

    But because I used it for so long and have had no problems it is confirmed that at least with tube amps or solid state with few tenths of output watts will not be a problem.

    And diffinatly sounds better than any other

    • I believe Frederik also makes the 1R0 in 10 watts, which is what Frank has. Frank is using the 100 watt Kronzilla SET amps … do you think that would be a factor.

      I know Pete thinks 10 watt resistors in that application should be fine. I think I’ll run it by Paul Mills and see what he says, but given your experience, Pambos, if you’ve been using a 5 watt Duelund resistor in that position with no problems then the 10 watt version should be fine.



  7. Are you sure the 1R can be made in 10Watts?

    I don’t think so. If it can be made 10 watts this discussion is over.

    As far as I know Duelund 0.5R-1R2 are 5 watts / 1R5-30R are 10 watts / 47R-50R are 5 watts.

    Please ask Frederik to enlightened us.

    I already answer a relevant email to Frank..

    The one I am using is 5 watts and never caused a problem.

    Any way the 1R resistor is not in Series with the woofer so it shall not change dramatically the sound, if the resistor is not the best on the planet.

  8. Theodoros also is using the 5 watt 1R Duelund resistor, with a 50watt amp and has had no issues.

  9. I have it in my hand. It reads: 1RO +/-5% 10w. My 47R is 5w

    • I think either the 5 or 10 watt rated resistors should be fine in the R5 position, but I have a message into Paul Mills to see if he has anything to add on the topic.



  10. Very well Frank.

    Then all shall be fine.

    47R is on the HF (tweeter) so no worries if is only 5 watt.

    I very much doubt it if the tweeter consumes more than 1-2 watts. regardless of what amp you are using.

    • I just heard back from Paul Mills, he said “Ten watt resistors will be fine in all positions.”

      So no worries on the resistor front.



  11. Thanks from all of us Jeff,

    You are a first class ambassador of Westminster Royal and Canterbury owners!


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