KEF recap. Kef Concerto speakers from the 1970s are revitalized with a recap of the crossovers

[@fabianoflaherty5574]

Nice one. I have the same 1004 crossovers and drivers in what seems to be a concerto diy kit of sorts. They still sound amazing and warm but I know they will benefit from a recap. After watching this I'm even more excited to make this happen. Thanks for great vid

[@ronjoiner]

Happy that I have helped in your decision.

[@robertlaws254]

Lovely to see. Thank you for posting this. I have three pairs of concertos. One pair I made from kefkit-3 with my father in 1971. I later bought another pair which seems to be a prototype: the crossover is built on a breadboard inside the cabinet. The third is another kefkit 3that someone else built. Robert, Cambridge, u.k.

[@ronjoiner]

I am glad you enjoyed it. During the crossover upgrade I bought a new set of Kef towers (Q750) and thought that I would fix the old ones, put them aside and focus on the new speakers. But the sound of the old ones is so nice and crisp after the upgrade that I now alternate between new and old.

[@ronjoiner]

Thank you.

[@nathanteach7266]

Very informative, Thankyou. I have a set of Heath kit speakers I am working on restoring. Same drivers, but different crossover board, so may need to hand match capacitors if they are different values. I would like to share a picture of the board. The inductors are larger. Don't recall how many caps. The speakers sound good but I sense there is room for improvement to demud the mid and de shrill the tweeters. (Suspect crossover has shifted down a tad on the T27's) Sounding like it will be well worth the effort. Thanks for the informative tutorial.

[@ronjoiner]

Hi, and thanks for watching. Replacing aged capacitors will always result in an improvement in sound quality. It is the cheapest way of reviving old speakers. For some speakers, it may not be a night and day difference but for mine, there was quite a noticeable difference in sound quality. My only advice is to buy audio-quality capacitors, those designed specifically for audio applications.

[@ronjoiner]

Thank you.

[@galleritegn4319]

Hi and thank you for your rendition, especially as I am going to have a look at a pair of Concertos tomorrow. I note that the capacitors are rated at 50v in the kit but you have decided to replace them with 100v items. I would be grateful if you could explain why? Thank you.

[@doubledark2]

what is it about the concertos that you lkike? did you end up buying them?

[@jeremycosmodavies]

Thank you for your reply. Yes, I bought the pair for their clarity and compatability with my Quad 303/33 and Thorens TD160 Mk2 vintage system. We opened up one of the speakers and assessed that the caps had not been changed. Why 100v rather than 50v rating on the caps? Thank you again for sharing with us.

[@ronjoiner]

@@doubledark2 I have had them since 1975.

[@Dyleet]

Thanks for posting this! I’m wondering, do you have advice on getting inside a KEF concerto cabinet that’s actually made by KEF? I have one - they don’t have any visible screws on the front panel. I can’t find any info anywhere online.

[@jameshutton5979]

The only way of getting into a KEF Concerto cabinet is by carefully pulling off its grill, unscrewing & lifting out its driver's.

[@ronjoiner]

@@jameshutton5979 Granted, but these are home built and the entire front can be removed to change out the crossovers.

[@jameshutton5979]

@@ronjoiner My advice is for a factory built KEF Concerto cabinet, which has no visible screws. I would suggest that a well built cabinet like your own has a superior performance than a factory built cabinet.

[@Redblower]

Thanks...will be doing mine in a few days

[@ronjoiner]

Basic soldering skills are all you require. Not a complicated procedure at all.

[@ikarus30449]

Is it really necessary?

[@ronjoiner]

Absolutely, a very noticeable difference in the separation of the 3 speakers.