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Refurbishing 30 year old speakers

Looking for advice on refurbishing speakers. I have owned a pair of KEF R107's since new. They are still some of the best sounding KEF speakers ever made IMO, but after 30 years they most likely could use some refurbishing. I'm not hearing any obvious deterioration of sound, but over time, I might just not be noticing the degradation. I would re-foam woofer surrounds, change ferro fluid in the tweeter, upgrade the crossovers, and possibly upgrade wiring. I'm Interested in anyone's experience and results with doing this. Did the refurbished speakers sound better than original, or even sound different? Of course the other option is to go speaker shopping and buy a modern speaker, but I have grown accustomed to the vintage KEF sound.....My only real beef with these speakers is the use of the outboard equalizer device called the KUBE which runs in the processor loop of the pre-amp. Never been real fond of having an active device like this in the system but admittedly the results still sound amazing. Thanks for your thoughts. 
dmiller01
11 responses Add your response
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rauliruegas
13,052 posts
 
Dear @dmiller01 :  ""   Did the refurbished speakers sound better than original, or even sound different? ""

My first hand experiences are that the speakers quality performance levls goes higher for the better not different at all.

I did it with my vintage ADS L2030 where I changed the internal fiber-glass damping foam ( the L2030 has a true bix box. ) by long-hair virgin wool, I rewired internally with all silver KCAG KK, I take out of the speaker the crossover and this crossover is totally hard wired from the drivers internal wiring all over the amps outputs.

Over the years I made and test several different caps, inductors and resistors going from boutique caps as Duelund, Jupiter, V-caps and the like and finished with the best  ( really the best, no matters what. ) caps that in my case are Wima FKP-1 along Kemet caps, Vishay resistor and pure silver ribbon inductors..

Outstanding changes success.

So, go ahead.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
cd318
2,636 posts
 
I once cleaned up and then soldered the heavily pitted driver tags on a pair of 1970s Celestion Ditton 44s for a friend who had kept them in storage for too long.

We both felt that the sound was noticeably better afterwards. Cleaner, more dynamic, with a faster bass. Just more 'modern' sounding.

On the other hand I also felt that some of that warm vintage sound character (coloration?) had been lost in exchange for the extra clarity.

Unless you have a very good memory it will be difficult to do a before and after comparison - unless maybe you do one speaker at a time.
elliottbnewcombjr
5,363 posts
 
Cones as well as surrounds need to be evaluated. Not sure what your's are made of.

I just re-coned one of my 15" woofers made in 1958 for the 3rd time since I got them in 1973. The one nearest the heater vent dried out, very small cracks ready to get bigger. It's twin brother on other side of the room was like new. They are again a mighty duo.

The impregnated domes of the horn's drivers can last forever, amazing.
jjss49's avatar
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jjss49
6,612 posts
 
https://www.simplyspeakers.com/KEF_bymfg_63-0-1.html

a go to source... not sure if they have parts for your specific vintage kef...
millercarbon's avatar
millercarbon
12,531 posts
 
The sound you like is largely down to the pleasing colorations of the cabinet and cones. New surrounds will not affect that much, if at all. If all you do is replace crossover components with somewhat better quality parts this won't change the sound you like very much other than to make it a little smoother and more detailed. You might actually want to be careful with caps as the really good ones can be so liquid it might actually take away some of the grain that is probably part of that vintage sound that you like. 


erik_squires
16,056 posts
 
Don't change any coils or caps without an impedance meter like Dayton DATS or a jig made for Room EQ Wizard.

You must match, or compensate for, changes in DCR/ESR especially in any components that shunt to ground.
mastering92
870 posts
 
Buy a new one online (check out vintage hifi shops or ebay) or look into newer KEF speakers with the same nominal impedance.

From the sound of things, the repair would be time-consuming. Your time is more valuable than your money.
dmiller01 OP
17 posts
 
Thanks for the responses. Much appreciated. 
dekay's avatar
dekay
5,556 posts
 
If the surrounds need to be replaced (woofers and possibly the mids) it should be easy enough to judge such by a visual inspection - then do it.

If the speakers still sound good/great I would then stop there and listen to them for a year, or so, before changing anything else.

If you can do the work yourself it's an inexpensive project (<<<$200) for what I recall as being KILLER speakers I listened to in the late 80's).

Curious as to what you power them with, as I could write a book on what a friend went through and ended up using (modded Hafler 500's).

DeKay


dmiller01 OP
17 posts
 
Thanks for the thoughts DeKay. They were KEF's flagship speakers in the late 80's and early 90's and KEF really overachieved IMO. Large, heavily braced wood cabinets enclosing twin down firing woofers make it hard to do a physical inspection without some disassembly, so I have been waiting for an audible problem! FYI, I am driving them with a Classe Six preamp and a Classe 15 amplifier. This is the older Classe gear from from the same era as the KEF's. Really sweet sounding SS gear. I have upgraded my digital front end to an Innuos Zenith Mk3 and Playback Design Merlot DAC. The Classe and KEF combo sounds really musical. 
dekay's avatar
dekay
5,556 posts
 
Just found a cutout view of the speakers, and yes removing the woofers looks way tricky.

DeKay
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