KEF 104/2 Restoration

Restoration includes:
Replacing the donut Surrounds on the 8" Woofers;
Replacing the Tweeters (with modification to the speakers);
Replacing the Capacitors.
This is my personal experience at restoring these British speakers.
After 3 decades, they once again sound like new.
Many thanks to my wife for providing the voice over.

[@jonas5000]

Thank you for putting this video together. It answered pretty much all questions I had when going through my restoration!

[@franksoos2937]

Thanks for your comment - I am really glad it was helpful.

[@pauljoyce4857]

Thank you very much for all the effort you've put into this instruction video. I'm starting the refurbishment of my own Kef104.2's and this will prove invaluable, thanks again.

[@franksoos2937]

Thanks for your comment. Glad to be of help. Good luck with the restoration. It's worth it :-)

[@brucegreer7201]

I appreciate the detail on this restoration. I am considering doing this and seeing both the simplicity and yet the details of doing this is really helpful.

[@franksoos2937]

Thanks for your comment Bruce. I have never done this kind of work before - It just took a bit of planning and some patience. Honestly, the hardest part was removing the bottom panel because it was siliconed in place. If you have just a little bit of "handyman" experience, it shoulddn't be too bad. Good Luck!

[@tharkthax3960]

Excellent job! Love to see the vintage gear brought back to life. Lovely sounding demo.

[@franksoos2937]

Thanks for the kind comments. It's amazing what a little bit of TLC can do. I did indeed record the sound directly off the speakers. Cheers.

[@christopherward5065]

Good work. Thank you for demonstrating the restoration. I have to recap my KEF reference 103s I have bought capacitors and resistors. Well done!

[@franksoos2937]

Enjoy!

[@ericbrock9387]

Thank you! I found a pair of 104/2 last week at the curb and they need some love. Your video will be invaluable to getting the repairs done.

[@franksoos2937]

They are an awesome speaker! Good luck with the reno.

[@jasonbuhagiar2997]

I did the same restoration a few years ago . It was good to see that it's normal to replace broken cabinet bases

[@franksoos2937]

Hello Jason, thanks for your comment. I wish it weren't so normal. I had a heck of a time removing both cabinet bases. I trust your restoration went well. Regards.

[@simongarantini1544]

What a fantastically clear and methodical video. I have no intention of restoring a pair of Kefs but now feel like I would be confident in doing so. Thanks for sharing your knowledge

[@franksoos2937]

Thank you for the kind comments.

[@Nick-sk1qp]

Wow, fantastic workmanship demonstrated by a very skillful audiophile. Thank you for sharing.

[@franksoos2937]

Thank you for your kind comments - much appreciated.

[@suntan8655]

Great detailed video. Thank you so much for the effort to produce this.

[@franksoos2937]

Thank you for your encouraging and kind comments. Always appreciated :-)

[@petergriffiths5762]

Definitely a rainy day -weekend project. Amazing to watch.

[@franksoos2937]

Thanks Peter for your kind comments. It was a great learning experience. Wish it was raining that day ;-)

[@20peterd]

BPeterso Just opened up my 104s. Only had to redo the donuts as the annulus rings looked like new. Discovered that the leads off the speakers were all long enough on my speakers to work on the cones without having to unsolder them. Thanks for the video!!

[@franksoos2937]

Thank you for your comment. Great that only the donuts needed replacing. Enjoy your KEFs :-)

[@TheHififink]

I also upgraded and replaced the original 5 way binding posts as these terminals do corrode over time. Thanks for the detailed tutorial.

[@franksoos2937]

Thanks for your comment - Glad to hear that the video was helpful.

[@harmvzon]

Thanks for this. I have these speakers for a long time and they sound as new.

[@franksoos2937]

Thank you for sharing. It is amazing how a little bit of TLC can make something old sound or look new again. Glad you are enjoying your speakers.

[@romiegumayagay8899]

Very informative video instruction. thank you Mrs. Frank Soos, well illustrated and videoed. congratulations. Now the big move is to do exactly on my ket 104.2 restoration.

[@franksoos2937]

Thank you for your kind comments. Good luck on your restoration. Go slow and take it one step at a time. I was no expert when I restored our speakers and it worked out quite well. You may also find some helpful tips in the comments below. Cheers!

[@bkatbamna]

Great job! It looked really tough but you made it look reasonable.

[@TheCookofthehouse]

Thank you so much. I just purchased a pair of 104/2 and noticed the need to repair /replace several components on the crossovers and the speaker donuts too. This video is so helpful because it covers the coplete list of operations to restore the speakers to their original glory. I couldn't believe how "simple" the operation is. Can not thank you enough Mário

[@franksoos2937]

Mario, Thank you for your kind comments. I am always pleased to know that this video has helped someone. Enjoy your renovated 104/2 !

[@kevinski1966]

You know what it always amazes me how others like yourself share knowledge for the sheer joy of doing so. This is a fantastically detailed video. Thank you so much for your efforts in uploading this!

[@franksoos2937]

Thank you so much for your kind comments. It is always appreciated. I am always glad when folks are able to make use of my experience and I am happy to share them. Cheers.

[@InXLsisDeo]

KEF should pay them for such a professional repair video. Very helpful. I am going to recap my 105/3, but I think I'll use some expensive Jantzen caps (non electrolytic) here and there. I will measure the cap values to 1% to try to match the original values as closely as possible, because from what I've read, in the original crossovers, the caps were measured, sorted by KEF to 1% and the crossover was recomputed by a computer for each pair of speakers, so that the overall response was within 0.5dB of the golden design. Obviously, there is no way to do that now, but I'll try to stay within 3% of the original values.

[@getoutofthekitchen]

Excellent video. Have a pair I bought in 1991 and still use. Have rebuilt both internal woofers and now need to replace the tweeters as they've gotten rather dull in the highs. Thanks for this wonderfully detailed video.

[@franksoos2937]

Thanks for your kind comments, John, I appreciate it. I am quite happy with the MDT29 tweeters. If I had the original T33s, I would have also considered replacing the ferrofluid. Cheers.

[@jimmccusker3155]

John - You can get replacement ferrofluid for the original tweeters and repair them by following this video. kzbin.info/www/bejne/raXJopSois55ntk

[@franksoos2937]

Thanks for sharing the info :-)

[@TravisLambert]

Thank you for the video, ordering my parts now, I got a pair of these at an estate sale this weekend for pennies, they sound great already but need the donuts too, I will do the same work in the video. Thanks!

[@franksoos2937]

That's Awesome! Good Luck with the restoration. Take your time and you will see that it's not that difficult. If you get stuck, feel free to shoot me a message. Cheers.

[@stevenhebert6117]

CAn't thank you enough for this video. We purchased a vintage home and in the woodshop were a neglected pair of KEF 104/2 speakers that need to be restored. Will be a fun project. Ours need the cabinets stripped and stained since the 2 speakers are different color stains. Can't wait to get started.

[@franksoos2937]

Thanks for your comment, Steven, it's always appreciated. It was indeed a fun project and very satisfying, you'll see. Good Luck!

[@backwoodsbillycreeks2174]

I don't have any Kefs but watched the entire video. They are built good. Wow.

[@franksoos2937]

Agreed, well made British speakers back in the 80's. Thanks for your comment :-)

[@calvinkan3449]

Great restoration! Very nice Kef speakers

[@franksoos2937]

Thanks Calvin. Amazing what a little bit of TLC will do. Indeed, nice sounding speakers.

[@ram360j]

You two are amazing thank you!!! I found some JBL-L110 speakers on the curb, we reformed and varnished them put new girls on them never thought of video it LOL thanks again!!!

[@franksoos2937]

Thanks for the comment. Sounds like it was a fun project. You are very welcome :-)

[@violao206]

This is truly a comprehensive DIY Refurb video that I shared with my twin brother. He has had his Reference 104/2's since the mid-'80s. I am more of a Vandersteen kid, and actively troll for audiophile info. I had learned about how the lower surrounds on these woofers fail. He's never really pushed them very hard, but it is hard to escape the basic chemistry of the material deteriorating over time. I know there is mad science behind the design of this system, but damn, this is a wee bit of a process to refurb them. Thank you for this video!

[@franksoos2937]

Thank you for your comment. I was initially a bit intimidated as well. Honestly, just going one step at a time and possibly recording your step as you go, didn't make it seem that bad. Slow and steady wins the race. Sometimes I think more effort was made in doing the video :-) Best.

[@cleetusm8739]

One of my favorite speakers... Great video.

[@franksoos2937]

Thank You! I appreciate your feed back. Indeed, they are a great product and it was totally worth the effort to restore them.

[@cleetusm8739]

I listened to a pair in 1987... Saved my $$ for months, as I knew that's what I wanted. Loved their sound. When I went to the dealer to finally purchase them, the price had gone up from $2,000 to $2,200 because of the exchange rate... I was crushed! Then I heard something coming from the other room in the store. I was drawn in. "A new exciting American company based in Kansas", he said. Martin Logan Sequels. I sat there with my mouth open. Introductory price of $2,000. Bought them on the spot.

[@franksoos2937]

Interesting story and thanks for sharing - goes to show that you never know what can happen. Hope you enjoyed the Martin Logan Sequels for a long time.

[@Jamboliner]

Great video. Thank you. It just might come in handy.

[@larsholmgaard]

Brilliant video! I need to change my donuts and this video was perfect. Thanks.

[@franksoos2937]

Thanks for your kind comment. So glad this video was helpful.

[@stevenkoski228]

My KEF 105 Series1 spkrs, which I purchased new in ‘79, are now 44yrs old, the drivers are in perfect condition, they sound excellent. The crossover caps ruptured after 20yrs, KEF replaced them, still working fine. Sadly KEF recently said they would no longer service my spkrs if needed😡.

[@franksoos2937]

Thank you for your comment. If KEF will no longer service your speakers, you may consider to DIY instead. I took the plunge and with a bit of homework, it worked out quite well. Cheers.

[@johnstraszewski3577]

Thanks for posting this awesome video. Hopefully I can use it to repair the tweeters that were damaged during some loud music.

[@franksoos2937]

Thanks for your comments John. Good luck repairing the tweeters.

[@k20aa]

Superb Video . Well done

[@franksoos2937]

Thank You! I appreciate the kind comment.

[@altairdesouza9368]

Congrats! Good job

[@franksoos2937]

Hello Altair de Souza, Thanks for your kind comments :-)

[@ernabanhidi5210]

Gratulálok! Nagyon szép és szakszerű munka! De jó volna itthon is egy ilyen hangfalon Jazzt hallgatni! Köszönöm ezt a videót!

[@franksoos2937]

Szívesen :-)

[@jimmccusker3155]

Very nice work. I have a pair in need of foam replacement, but my speakers might be older since they have foam on the outer part of the woofers (not rubber). I also think the cross-over is at the bottom of the cabinet. Hopefully the cap replacement is the same, but I'll check with Falcon. Lastly, I have the original T33's and may try refurbishing them since I have the ferrofluid and have seen the refurbisment video of them on KZbin. Now I just need to invest in the time to do the project!

[@franksoos2937]

Thanks for your kind comment - Good luck with the restoration. It really was worth the effort. Nice that you still have the original T33s.

[@petiohristov7104]

Perfect job!

[@franksoos2937]

Thank You! :-)

[@ewizzle2]

That tweeter just wow 👏

[@franksoos2937]

Thanks.

[@swingmanic]

An awesome video..I'm looking at buying a pair of these locally.

[@franksoos2937]

Thanks for your kind note. If you need to make any renovations, slow and easy is the trick. Hope this video will also assist you. Cheers.

[@swingmanic]

@@franksoos2937 I bought them - Just loving the warm sound. Stan Getz and Miles Davis never sounded so good!!!🤭🤭

[@mborgmann90]

Thank you for this video! ❤️

[@franksoos2937]

Thank you for your kind comment 🙂.

[@AndreasGarvik]

Many thanks for execellent video.

[@franksoos2937]

Thank You - I appreciate your feedback. It was a great experience and I am glad to share it.

[@junichiikeda5860]

Great video. I see a pair for sale locally at a shop. Not sure they did all the work you all did. Thanks for a very interesting video.

[@franksoos2937]

Thanks for your comment - Check inside the porthole, you should be able to see if the dome is in good shape. Cheers.

[@georgemunoz8919]

I enjoyed every minute of it. I wish I had the skills to do it but sadly I’m not brave enough to attempt it. Will have to find someone to do it for me.

[@franksoos2937]

Thank you for your kind comment. For what it is worth, I had the same trepidation. I just took it one small step at a time and it is amazing at what one can do. Best Wishes.

[@sergiogomezphotography]

Wow, this is the best video on any restoration I’ve ever watched, your skill and your wife’s narration are top notch . Congratulations. I’ll subscribe and share this video

[@franksoos2937]

Thank you Sergio. I appreciate your kind comments.

[@fakeusa]

Well made video!

[@franksoos2937]

Thank You for your kind comment - It was an all around great experience. When others can benefit from it, all the better. Cheers.

[@kapenakanaiaupuni5816]

Wow 1984 .awesome job

[@franksoos2937]

Thank You - I appreciate the comment. It was a fun experiment and a joy to share.

[@2ChannelAudio]

Good job 👏

[@franksoos2937]

Thank you - I appreciate it!

[@sudhirsumongkol8972]

Great all around.

[@franksoos2937]

Thank you very much - I appreciate your comment.

[@MrPINKFL0YD]

Thank you for the video.

[@franksoos2937]

Thank you for your comment. Hope it can be of some use.

[@GlassWolfLH]

As of 2023, capacitor kit (2 speakers) runs about $200 shipped to the US. Inner and outer surround replacement kit is about $80 (2 sp.) ferrofluid replacement is about $20, MidWest direct replacement tweeters are $45 each, and speaker binding posts can run from $15 to $80 (set of 4) so a full restoration will run between $300 and $400.

[@franksoos2937]

If I still had the original T33 tweeters, I would have replaced the ferrofluid (also less expensive). Thank you for the info, it's appreciated.

[@muppetb.lansing8374]

This is a great guide, but a couple of thoughts from someone who has restored two pairs of these. Firstly, replacing the T33 stock tweeters should only considered (IMO) where the original tweeters have blown. I have read various reports that people prefer the sound of the original tweeters, a simple ferrofluid replacement is an addition to your procedure above, and takes about 30 minutes per tweeter, Secondly, I never did the cap replacement in the crossovers and I also researched this extensively. These caps are very well built and its arguable they dont actually need replacing. The two pairs of speakers I did still sounded great without this (and I am generally a fan of recapping amplifiers). The other issue is that the caps you need can only be obtained from falcon acoustics in the UK and they can be VERY hard to deal with and are often out of stock of values, or send you the wrong parts.

[@franksoos2937]

Hi and thank you for your comments. I would like to reply to your greats thoughts. The stock tweeters; These blew long before I did the restoration. Before I really knew anything, I took them into a audio shop and they simply replaced them with something else ( I made mention of it in the video). In hind sight, I agree with your statement, I would have preferred to replace the ferro fluid. The Caps; from what I researched, it was better to replace them given the age. As you stated, it likely would not have made a difference but since I was knee deep into the process, I though why not, could not hurt. Falcon Acoustics; They were actually extremely helpful and very easy to deal with. I really have zero complaints. The caps were in stock and were shipped right away. Maybe I got lucky :-) Cheers.

[@bluefloyd6058]

@@franksoos2937 Jerry @ Falcon is a top notch guy.

[@franksoos2937]

@@bluefloyd6058 Sounds like it went well for you 🙂.

[@GlassWolfLH]

MidWest Speaker Repair has direct T33 tweeter replacements available. No modification to the cabinet required as with the Morels. Speaker grilles can be re-covered as needed as well, with speaker cloth from Amazon, and some 3M Super 77 spray adhesive. Speaker binding posts can also be replaced with posts from Dayton Audio, or Amazon. If you have the bi-wire 104/2 models, be aware that you will need a slightly different set of capacitors from Falcon, so let them know you have bi-wire speakers, or just pull the networks out, and write down a list of the caps you'll need, and let them know. The bi-wire speakers used different crossover networks from the two-post models. I encountered this when restoring my bi-wire models (have done 3 pair thus far over the past 20 years)

[@franksoos2937]

Thank you so much for this info. I'm sure this will help anyone wishing to install T33 tweeters, speaker cloth, binding posts and/or capacitors. Thank you again for your contribution. Best.

[@1959Berre]

This video is very well made. Another video about this speaker by somebody else was impossible to endure because of endless repetitions and boring, unnecessary explanations.

[@franksoos2937]

Thank You! I appreciate your comment.

[@noellucas60]

Hi mister Frank Soos. Thank you for your very good video. I plan to restore my Kef 104/2 in Belgium, and i ask me if it is much better with the Morel Mdt 29 or replace only the ferrofluid of t33 tweeter is also good, but under the tweeter Morel?

[@franksoos2937]

Thank you for your comment on the video. If I had the original T33s, I think I would have initially tried to replace the ferrofluid. Since I no longer possessed the original tweeters, the MDT 29 was a good alternative for me. Good luck with the restoration - it's worth it :-)

[@raffaellifurio9901]

Thanks for your video, probably the best around this job. I agree with who suggest to replace electrolytic with different caps. Don't you think the white sealer applied on the center could modify the woofer characteristics?

[@franksoos2937]

Thanks for your note, comments are always appreciated. I'm sure that the solid caps would have been fine. My goal was to restore them to the original specs in an attempt to reproduce the original sound. The sealer was applied to extend the life of the woofers. I don't believe I could ever tell if the sealer modified the characteristics of the woofer. I'm not an expert at restoring speakers so I'm sure that there are different or better ways of doing what I did. What I could say for certain is that the speakers truly sound amazing, especially given their age. Cheers!

[@robn7777777]

Thank you for sharing

[@franksoos2937]

Thank You!

[@robn7777777]

@@franksoos2937 Thank you again - and your wife - for one of the most excellent instructive videos I have ever seen, just the right pace and level of detail for me. Now I need to find a nice pair of 104/2s!

[@franksoos2937]

@@robn7777777 Thank you again for the compliments - We tried to make it as informative as possible and balance it with some interest without making it too long. Cheers!

[@Aqualung1956]

So was there a notable improvement in sound after recapping? I have a pair and have replaced the tweeters and had the woofers professionally done, but they can still sound a bit "muddy" on a lot of recordings. Thanks!

[@franksoos2937]

Hi - Really hard to say. It was recommended to me by the capacitor manufacturer that because these caps were not solid state caps, it is very likely that the substance inside has started to harden up - especially after about 30 years. I was doing a reno on these speakers anyways so it was also easier to do it at the time. Cheers.

[@Aqualung1956]

Thanks Frank. So, just to clarify, Did you give a serious listen before and after or did you do the work for someone else? Excellent job btw! I ordered the cap set from Falcon, problem is I am not good at these kind of things and my local guy will charge me $200-240 for the work.

[@franksoos2937]

HI Again - I did the work for myself. I really couldn't listen to the speakers ahead of time mainly because the woofers were shot. I never did such a job in my life and managed to do ok. If you go step by step, It's not rocket science. Maybe watch the video a couple times, save a few bucks and treat yourself afterwards. Good Luck!

[@fredgien]

She has a lovely voice!

[@brucegreer4386]

I am trying to restore my later version of the 104. Some of it is easier (the bottom plate comes off easily as it isn't glued and the crossover network is attached to that plate). But where were you able to match the capacitances? My network has values like 4.2 mfd, 7 mfd, and 3 mfd, none of which I have found yet.

[@franksoos2937]

Hi Bruce, Falcon Acoustics (in the UK) had all the originally matched caps for my 104s. Here is their website: www.falconacoustics.co.uk/ Great to hear that the bottom plate came off easily and simpler to access the Xover circuit. Hope that helps. Cheers, Frank

[@stevieg2755]

Where can you buy the stuff you treated the center donuts with.Isthere a commercial Home Depot version? Steve

[@franksoos2937]

Hello Stephen and thanks for your note. I doubt that a place like Home Depot would carry such a specialized product. I purchased the Liquid Foam Guard Sealer as an option with the repair kit from Simply Speakers. Here is the website: www.simplyspeakers.com/kef-104-speaker-foam-edge-repair-kit-fsk-kef104c.html# Cheers.

[@matrempit2885]

Thanks sir...👍👍

[@franksoos2937]

Thank You for watching :-)

[@johnstraszewski3577]

How did the speakers sound after changing out the tweeters, compared to the original units?

[@franksoos2937]

That's a tough question. I had the original tweeters replaced many, many years ago. The tweeters I replaced (in the video) were not the original ones to begin with. Either way, the sound is great. That said, if I was still in possession of the original tweeters, I may have considered replacing the fluid inside of them. Unfortunately that was not an option for me when I did the renovation. Good luck with the repairs.

[@NPGmember]

Verry good vid +++++

[@franksoos2937]

Thanks! Appreciate the comment. :-)

[@jesperosterberg2588]

Nice educational video! One question about the tweeter. Do I need to modify the crossover filter for the Morel tweeter?

[@franksoos2937]

Hello Jesper, I did not modify anything to the crossover filter. I simply installed the tweeter as is (except for the minor physical modification I showed in the video), replaced all the electrolytic capacitors and it worked great. Thanks for the compliment on the video :-)

[@jesperosterberg2588]

Thanks for answer. I am thinking och replacing the grommets to, where did you get them?

[@franksoos2937]

Here you go.....have fun! www.midwestspeakerrepair.com/shop/speaker-repair-kits/rubber-grommets-for-kef-104-2-105-3-woofers-12-pack/

[@jesperosterberg2588]

Hi! Thanks, that´s the place to go.

[@thomasdiyaudio5353]

Very good work to restore this pair of vintage speakers. By the way, why not upgrade all the internal wiring as well? Also upgrade the small value capacitors to GAD or Mundorf?

[@franksoos2937]

Thanks for your comment. All the wires appeared to be in very good shape. From what I researched, it was mainly the electrolytic capacitors that needed to be replaced given their age. And honestly, I never even considered changing anything else. Good consideration for anyone else wanting to do a restoration.

[@sdcllc8727]

This is a great video! Any idea if doping the doughnut keeps them from drying out the same way as the original?

[@franksoos2937]

Hi and thank you for your kind comment. I am unfamiliar with doping the donut. I am only aware that the sealer I applied in the video is a way to preserve the donut. That is not to say that there are other, and possibly better, ways of doing the same job. Cheers.

[@sdcllc8727]

Yes, the sealer. Is there any evidence that it will make them last longer. I'm about to change the donuts on a pair of 103/3 and I'm curious if it will make them last a bit longer.

[@SuperRedSilk]

Hi Frank, wonderful video. I'm planing on replacing the donuts in my Kefs. I'm curious though, why did you decide to change the tweeters, for the sake of it? And also where did you find the grommets? I'll also be using simply speakers parts. Regards Jason.

[@franksoos2937]

Hello Jason, Thanks for your kind comments. To answer your questions: One of the tweeters wasn't working so that's what prompted me to replace both of them (with a slight modification to the cabinet). For the grommets, here is a link to the website: www.midwestspeakerrepair.com/shop/speaker-repair-kits/rubber-grommets-for-kef-104-2-105-3-woofers-12-pack/ If you take it step by step, it's not too difficult and the outcome is definitely worthwhile. Cheers!

[@SuperRedSilk]

@@franksoos2937 brilliant, thanks Frank.

[@franksoos2937]

No Problem :-)

[@marcevo3540]

Yea really I dont even have these speakers and I watched the whole video hehe. I have a pair of Energy 22 pro and was looking for videos and ended up watching this.

[@franksoos2937]

Thanks for your comments, hope this may be of some help.

[@factorylad5071]

Hi Frank , I have enjoyed watching your video although I do not own Kef 104.2 s , no I have the Kef 104 AB s, which I have lived with for a long time. These look a bit special because they have a polypropylene after fit suspension on the bass units and they look and sound like they are made to last. Having said all this, I am a little bit sceptical of the economics of a crossover recap. To be specific , the cap kits , wouldn't they have to be pair matched ? which I assume is the practice at the factory. Do any suppliers offer pair matching ?, I wonder.

[@franksoos2937]

Hi, The Caps I purchased from England were OEM parts and at no point was there ever any discussion about matched paired caps. You may very well have a valid point; I never thought of it and the supplier never mentioned anything. In the end, my KEFs have a new lease on life - they sound very good. I thought it was definitely worth the effort (although I think I put more effort in making the video, lol). Thanks for the comment :-)

[@BasementBerean]

I have a pair of these I purchased in 1995. Do these speakers just decay on their own, or only when exposed to certain usage, climate, etc. kinds of conditions? How can I tell if mine need restoration? They seem to sound fine.

[@franksoos2937]

Hello, from what I have experienced, the donuts on the woofers have a tendency to deteriorate over time (mine were over 30 years old) from normal usage. I would imaging that certain conditions, such as climate like you mentioned, might cause the deterioration to accelerate. With the help of a flashlight, have a look inside the base reflex hole and examine the donut surround in the middle of the lower woofer. If it looks anything like the one in the video, if will need to be replaced to restore the sound quality. The speakers may sound "fine" but they aren't producing sound at their optimal level. Hope this helps. Cheers.

[@BasementBerean]

@@franksoos2937 Well, I did what you said and my donuts have gone stale. Just like your "pre-restoration." I don't have your set of skills, and I have so many other things to attend to, and I tend to move a lot and have been lugging these through life for the past twenty years. Good audio years, but still at times I want to be rid of them. Perhaps it's time to let them go to someone who will restore them and enjoy them. Thanks so much for your video.

[@franksoos2937]

Thanks for your reply and best wishes.

[@bridgebolt51]

how much you pay for the capacitors for both speakers?

[@franksoos2937]

About $130 USD. Found them in the UK at a place called Falcon Acoustics.

[@larrysmith7168]

Hey Frank. I'm struggling to find a crossover schematic for the KEF 105/3. Any chance you can help ID what C33 is?

[@franksoos2937]

Larry, Sorry I cant help with C33. I would suggest checking with Falcon Acoustics. I got all my caps from them and they were very helpful. They may know. Good luck. www.falconacoustics.co.uk/

[@larrysmith7168]

@@franksoos2937 Will do. Many thanks!

[@franksoos2937]

@@larrysmith7168 Hello Larry, Regrettably, I have zero experience with the KEF 103/3. Sorry I cannot be be any help in that area.

[@MD0MDI]

Thanks for this, I have a set that is suffering the same as yours, Could you please pass on the details of where you bought the parts from, I am OK with the capaciors, but the rest of the gear I could do with finding a supplier., Thanks for the great video,.

[@franksoos2937]

Thank you for your kind comment. Here are the links to where I got the supplies. I included all the links in case others would like to know. Good luck with your project. Foam Surround: www.madisoundspeakerstore.com/morel-soft-dome-tweeters/morel-mdt29-4-4-ohm-textile-dome-tweeter/ Rubber Grommets: www.midwestspeakerrepair.com/shop/speaker-repair-kits/rubber-grommets-for-kef-104-2-105-3-woofers-12-pack/ Capacitors: www.falconacoustics.co.uk/kef-104-2-replacement-capacitor-set.html Morel MDT29-4 (4 ohm) Tweeter: www.madisoundspeakerstore.com/morel-soft-dome-tweeters/morel-mdt29-4-4-ohm-textile-dome-tweeter/

[@juliantallach3682]

Hi, I have a pair of these and I noticed lately that one seems to be quieter than the other, do you know what could be the cause? Many thanks.

[@franksoos2937]

Hi and thanks for your enquiry. What I could suggest (maybe you have already tried this) is to swap your Left and Right speakers to make sure it is not an amp or speaker cable related issue. Also, get a strong light and a mirror and look inside the base reflex hole for any obvious signs of damage or wear to the woofers. If the problem persists, it could be a variety of issues which are beyond the scope of this video. Hope you are able to find the problem.

[@juliantallach3682]

@@franksoos2937 Thanks very much for the advice, I'll try these things. All the best.

[@franksoos2937]

@@juliantallach3682 Good Luck - Cheers.

[@stephenyoud6125]

Agreed on the electrolytic caps there. Sadly a missed opportunity to further improve the sound quality. Replace the electrolytics with Polypropylene types. Eg JB Caps, Jantzen, Mundorf. (There’s a really good capacitor test review on Humble Homemade HiFi). The Dayton audio caps may be made by Bennic in Taiwan and although Polypropylene they’re fairly bargain basement but still better than electrolytics. Add a Bypass cap on the Tweeter capacitor (I use Cornell Dubilier 940C 0.01uf on budget upgrades, see the Humble Homemade HiFi review for other suggestions). But a much better upgrade on the Tweeter circuit would be Sonicaps with a 0.01 uf Miflex copper foil bypass cap. And more regular Polypropylene caps on the Mid and woofer circuits. Only Use wire wound resistors (not the standard ceramic types), eg Dayton or Jantzen and replace the iron cored inductors with Wire wound air-cored types eg from US Coils. To learn more about such speaker upgrades, follow the GR-Research channel and Danny Ritchie.

[@franksoos2937]

Stephen, thank you for all the great info. I went with what I knew and how to proceed at the time. Hopefully others reading this will give them other options to consider when refurbishing their KEFs. Honestly, the speakers sound fantastic. I was really happy with the outcome. Best.

[@stephenyoud6125]

@@franksoos2937 sure thing Frank. consider it on the next upgrade. See this Kef upgrade from Danny at GR-Research

[@franksoos2937]

@@stephenyoud6125 Thanks Stephen, I appreciate the info. Best.

[@paulsiaw7796]

Hi. Good replacement for the tweeter. By the way, may i know you still kept your original kef tweeter? I am interested to buy it from you.

[@franksoos2937]

Hi Paul - I no longer have the original T33 tweeters. I had them replaced with TS1191 tweeters many years ago. I still have the TS1191 tweeters (not the original KEF tweeters).

[@paulsiaw7796]

Hi Frank. Thanks for your reply. How is your 104/2 sound after change the tweeter to Morel MDT29? Is it sound similar?

[@franksoos2937]

Hello Paul, Sounds actually quite good. Tough to make the comparison since I havn't heard the original sound for quite some time. I was really, really pleased with the outcome (especially with the other changes - fixed woofers and new caps).

[@paulsiaw7796]

Hi Frank. Good to know that, thanks for your great video. Like a lot..

[@franksoos2937]

Thanks Paul - appreciate your comment!

[@oh_rhythm]

morel twitters are awesome

[@jeffschotland9847]

Are the alcap capacitors from Falcon marked for the negative pole?

[@franksoos2937]

Hi Jeff, these capacitors were not marked. I am thinking that these particular capacitors are not polarized. Sorry for the delayed response.

[@jeffschotland9847]

@@franksoos2937 thanks! I have already finished restoring my 104/2’s. I was very lucky that the bottom access ports were just screwed in place. Thanks for your guide.

[@franksoos2937]

Thanks for the follow up reply and congrats on your restoration. Glad I could help. Best!

[@lievenm4753]

Fill the gap with shims before removing old deteriorated foam to avoid gap filled with debris

[@franksoos2937]

Thanks for the tip :-)

[@johnsweda2999]

I would have used another wide bead of blue tack for the bottom when attaching not just the weather strip Not sure why you had to change the original tweeters how do these compare to the original spec, That's the question?

[@franksoos2937]

Hello John, Thanks for your comment. Indeed there are a few things I would have done differently if I could do it all over again. As for the tweeters, at the time I could not find any original ones, replacing the ferro fluid seemed somewhat more difficult (in hind sight I would have tried it) and so replacing the tweeter was the choice of the day. Honestly, it still sounds great for a speaker that is about 40 years old.

[@GforceMI1965]

Next time you need Kef info from the UK, Wilmslow Audio is the place to contact.

[@franksoos2937]

Thank you for sharing the info. Regards.

[@GforceMI1965]

You're welcome, even Kef recommends them, and thx for the heads up with Falcon Acoustics, i'll be getting myself a full cap kit for my 105.3's from them myself :-)

[@franksoos2937]

Good Luck replacing them - not that hard of a job. I'll bet your KEFs will sound great!

[@GforceMI1965]

Thanks, I'm an electronics hobbyist so it won't be to much of a job, and owned them from new, so I know they'll sound amazing once done :-) The 105.3's are a bit special imho.

[@franksoos2937]

I bet they will sound great. Take care.

[@g.fortin3228]

Wow never saw anyone use a big weller solder-gun on a pc board before.. he's got skill not to burn it. but not the best way to teach, as a smaller iron much more suited to the job. A nice restore there and i'm sure they sound great !

[@franksoos2937]

Thanks for submitting your comment. Noted on the big Weller soldering gun. Unfortunately it was the only one I had and so I made the best of it. And yes, the KEFs sounded amazing! It was a treat to get them working again. Cheers!

[@yttean98]

You have reviewed a few 2-way speakers already, I like to suggest you review the latest Q acoustics 2way Active comes with Hub. That would be interesting. Advise them you operate a KZbin channel reviewing Hi-Fi gear they will probably loan you a pair so you don't have to buy. Plan ahead you might be able to get a pair in a few weeks or months.

[@franksoos2937]

Hello, Unfortunately I do not review speakers or operate a KZbin channel reviewing Hi-Fi gear,. The purpose of this video was to share my personal experience in restoring the KEF 104/2 speakers hoping it may be of assistance to others.

[@zorst99]

I wonder if you two considered upgrading your caps to poly? I have some B&W 801s that I have had since the 70s, I always felt that the mids were a little lacking. I even changed out the mids at one point to see if it made a difference, it didn't. So I finally upgraded the caps to Solen poly caps. and wow. Instruments took on a new life. I also have some B&W802Ds and now the 801s sound much more like the newer 802s I know back in the 70s and 80s most speaker companies did not use poly caps but now all the better speakers do use them. I have compared my speakers to other that cost a lot more and the 801s tear them apart now. The tweeters had poly caps that I did not change but I did change the mids and lows. I have a very nice sub but now I have removed the sub from the system. The speakers handle the job nicely themselves I've always felt that with 12 inch woofers what was I doing needing a sub. 2 stereo 12s couldn't do the job of one 12" sub? Nice video 0.

[@franksoos2937]

Off and on I have wondered what the speakers would sound like with poly caps. At the time I was a bit of a stickler to remain with OEM parts cause that is what KEF used. Obviously it is kind of history now. I must say though, for speakers that are about 40 years old, they sound darn good. Thank you for your input - nice to share other's perspective. Cheers.

[@zorst99]

@@franksoos2937 what I found the stereo image improved to where you could pinpoint the instruments better. Instruments were much sharper in detail. I think the distortion level decreased pretty dramatically and I've always felt the speakers best feature was their low distortion. Bass now seems to also be more dynamic. I feel like I should tear them apart and replace even the old film caps that I kept in there. But they are my B speakers so it's not really critical.

[@franksoos2937]

@@zorst99 It would have been interesting to hear the difference. I have gifted the speakers to my son a couple years ago so he may chose to go that route some day. Thanks again for your input. Cheers.

[@Jamboliner]

Hey frank, could specify which kit you purchase and why did you change all the capacitors? I ask this because all the kits I see out there come with 4 donuts and 4 outer suspension foam. My woofers do not need to change the outer foam because it ain't made of foam, it is made of rubber, and like in your case, they are in good shape. And this is something I want to do, instead of sending them out costing a fortune. I should have the skills.

[@franksoos2937]

Hello Joao - Thank you for you kind comments. This is the kit I purchased from Simply Speakers.com = Part Number:FSK-KEF104C I did not need to replace the outer suspension foam (rubber) either and I could have saved myself a couple bucks by purchasing only the center donut foam = Part Number:FSK-KEF. I did not realize at the time that the center donuts were available on their own. Why change the capacitors? The original 104/2 KEF capacitors had an electrolytic interior. From what I understand, it's like a gel and the gel is prone to hardening over the years (decades) and not allow the KEFs to produce the sound they were originally intended to. I could have done nothing and maybe gotten away with it but since I was doing a complete restore it seemed like a good idea to change the capacitors as well. Side note: during my research, I was presented with the idea of using solid state capacitors instead. This would have been a viable (possibly cheaper) solution, however, in order to preserve the "original" sound of the KEFs, I elected to replace the capacitors with the original ones. Long answer - sorry. You mentioned "having the skills" - I did not think I could do it either but it worked out very well. One word of advice, do not try to scrape all the glue away from the cones when replacing the center donuts. Good luck :-)

[@Jamboliner]

FRANK SOOS I have watched the video several times. And thanks to your wife's awesome job with the narration, I will remember to take care while crapping the Woofer, I should Know talent when I see it, I am a sound operator. Once again, in the end, a great video was produced with awesome results. A win-win situation. I will attempt this. With this kind of information what could ever go wrong, at least no surprises, which is great. I will order from falcon acoustics the capacitors. On the web site they seem to have with 5% and 2% tolerances, the later in limited supply. Will have to investigate further. Cheers

[@franksoos2937]

Hey Joao - Thanks for the compliments - I passed them on to my wife as well :-) I have a string of emails between myself and Falcon Acoustics regarding the installation of the capacitors. I am willing to share that with you as it may be of some help. How can I send it to you? I prefer to not post it on this site.

[@Jamboliner]

I would very much appreciate that. I suggest a forum of some sort, where we can PM each other. Because we ain't exchanging emails addresses here are we? By the way I decided to refurbish the T33's. It's only a mater of removing the old and dried out ferro fluid and replacing with new fluid. You can find it also at simplyspeakers too! By the way frank, you didn't throw the T33's to the bin did you? I am guessing you didn't. You could and should, along with your wife maybe, and makes us a video refurbishing the T33, that would be icing on the cake and a little cherry also. Can't strees enough how much this video motivated me.

[@franksoos2937]

If you are a FaceBook user, PM me and I'll send the info about the capacitors. I had the T33s replaced over 10 years ago at a store, so they are unfortunately long gone. As I mentioned in the video, I was replacing TS1191, which are not the stock T33s. Thanks again for your kind comments!

[@TomTom-xe9gq]

I have same this version of the speakers . For save the bottom panel I dripped acetone all around the seams wait about couple minutes before pry it out.

[@franksoos2937]

That sounds awesome. That would have saved me some work. Thank you for sharing. Cheers.

[@TomTom-xe9gq]

FRANK SOOS Thanks for your video , I learned from your mistake LOL.

[@franksoos2937]

:-)

[@SunsetfearOFFICIAL]

do you sell them ?

[@franksoos2937]

Good Day, I am sorry - I do not sell anything in this video. It was a personal project I was willing to share.

[@vintagestereo5491]

So to get to the filter you must remove the down bass, but in another video, I saw that the filter is inside the side of the bottom panel

[@franksoos2937]

Hello, by "Filters" I assume you are are referring to the circuit board with all the capacitors. I recall seeing some models online where the board was indeed located on the bottom panel. I am not sure if these were earlier or later models than mine. With my speakers this was obviously not the case.

[@vintagestereo5491]

@@franksoos2937 The only thing I have to do to find out is to open the bottom ; )

[@franksoos2937]

@@vintagestereo5491 It's a bit tricky - In one of the threads below, someone dripped acetone all around the seams and waited couple minutes before prying it out.

[@yogendersingh282]

Sir How to make crossover design Please to upload full video.... Thanks

[@franksoos2937]

I am sorry to say that "crossover design" is not in my area of expertise.

[@weareallbeingwatched4602]

Pressed steel baskets? I can see why they needed that rod.

[@francescodali224]

hi the quality kef from the 80s, incredible age, unfortunately today it is no longer the case.

[@franksoos2937]

It is truly amazing the quality of speakers KEF was able to produce over 40 years ago. Thank you for your comment.

[@socksumi]

Do yourself a favor and DON'T buy electrolytic capacitors. Buy polypropylene types or polyester film if you can't afford polypropylnene. Big improvement in sound by getting rid of electrolytics. Upgrade the resistors to high power wirewound types. Dales are good ones and not too expensive.

[@franksoos2937]

Thanks for you input.

[@ikarus30449]

Excellent video - but a shame for KEF, that built in so much crap. I would never buy a KEF speaker again.

[@franksoos2937]

Hey Paul - Thanks for your comment. Lots of good options out there today.

[@ikarus30449]

@@franksoos2937 Thank you. Same to you.

[@JamesE707]

Can I ask - why is KEF 'crap'?

[@hansschlenstedt9527]

@@JamesE707 I have a pair of KEF Calinda, built 1981. They sound well. But the quality of material is poor. Nearly crap. Would never buy again a KEF speaker.

[@oldscoolhifichannelgmh3574]

folienkondensatoren wären sinvoller und viieeel besser

[@franksoos2937]

Thank you for your comment. My intention and preference was to preserve the original sound of the KEF speaker which is why I opted to use the original capacitors. Cheers.

[@oldscoolhifichannelgmh3574]

@@franksoos2937 ja aber durch die Kondensatoren wird ihr volles potenzial begrenzt durch die Foli Caps wär es besser und sauberer und Geradlineger des Übertragungsbereichs...

[@franksoos2937]

@@oldscoolhifichannelgmh3574 Thank you for the follow up. That does sound like it could have been a good option. I was not aware of that option. In the end, I really like how it turned out.

[@socksumi]

I'm appalled that Kef used foam in any of their drivers.

[@Aqualung1956]

Yes , be sure to listen to this guy instead of the company that actually made the speakers.

[@richardsinger01]

Maybe it was because they considered it sonically better than the alternatives at the time.

[@cliosport24]

Very bad camera angle.

[@franksoos2937]

Thanks for the feedback - As this was my first "How to Video", there are other aspects I would change if I were to produce another one, including camera angle. My main objective was to share my experience in this completing this project. Regards.

[@daveblane6442]

narrator --sounds like a dude

[@boris1968-i8l]

Why not MKP caps...

[@franksoos2937]

It was definitely an option I considered. In the end, my preference was to preserve the "original" specs.