KEF 104/2 vs ADS L710

[Raynald]

Mine were color coded in the standard red and black (plastic). I replaced them with these: Dayton Audio BPA-38G HD Binding Post Pair Gold from Parts Express.

Nice upgrade. Early 104/2 had the plastic terminals, later versions had all metal ones that looked more the part on a speaker that price.

 

[hwystar]

Mine have the all metal ones and no markings or colors to indicate polarity. A google search turned up the afore mentioned headache inducing article that ex[plains how to determine correct polarity.

 

[Raynald]

Mine have the all metal ones and no markings or colors to indicate polarity. A google search turned up the afore mentioned headache inducing article that ex[plains how to determine correct polarity.

Interesting evolution of terminals:

I don't remember these, very early production?

https://on-mag.fr/images/com_adsmanager/contents/enceintes-kef-104-2_4012_3.jpg

These are the early plastic ones I first remember selling

https://img.photobucket.com/albums/v668/Lee_Vuong/Kef speakers/IMG_2279.jpg

The later upgraded metal ones, polarity marked with coloured rings as on my R107

http://oi58.tinypic.com/2dbt5om.jpg

I think the bi-wire version, also with polarity markings, came along after I left the business

https://img01-olxpt.akamaized.net/i...reference-bi-wire-1991-ltima-gerao-lisboa.jpg

Possibly it is not Kef to blame for the lack of markings, could yours have been installed by a previous owner?

 

[baco99]

Mine were color coded in the standard red and black (plastic). I replaced them with these: Dayton Audio BPA-38G HD Binding Post Pair Gold from Parts Express.

Jut use Google images. Red on the right if you are looking at the back of the speaker. This is a generally accepted, not standard, way of doing things by most speaker companies.

 

[hwystar]

Thanks a bunch. After looking closer they do have the colored rings. Covered with dust, maybe that's why I didn't see it but kind of obscure. If it weren't for you guys I still would not have figured it out. And I had them connected wrong too! For the record I have the metal ones in Raynald's 3rd link above.

 

[hwystar]

Much to my surprise after switching the polarity I was listening to some music and I started to notice that I thought I could tell a difference, they sounded better than they had before I thought.
The surprising part...I then realized that I had the ADS L710s playing. I then switched the selector back to the KEFs and I don't think they really sound better than the 710s and in fact don't sound as good. I still have a bad midrange on the 710s too!

So, I'm sure the KEFs need something. Recap, ferro fluid, woofer surrounds? A proper restoration is probably in their future. They don't sound bad but they don't best the 710s either. (in my opinion and my wife's) My amp right now is a Sansui AU11000 for what it's worth.

 

[darkblue94]

Much to my surprise after switching the polarity I was listening to some music and I started to notice that I thought I could tell a difference, they sounded better than they had before I thought.
The surprising part...I then realized that I had the ADS L710s playing. I then switched the selector back to the KEFs and I don't think they really sound better than the 710s and in fact don't sound as good. I still have a bad midrange on the 710s too!

So, I'm sure the KEFs need something. Recap, ferro fluid, woofer surrounds? A proper restoration is probably in their future. They don't sound bad but they don't best the 710s either. (in my opinion and my wife's) My amp right now is a Sansui AU11000 for what it's worth.

You can not realistically judge the KEF speakers until after the restoration has taken place, in fact you can cause permanent damage to them by playing them beforehand.

 

[bigx5murf]

If your tweeters have ferrofluid, playing them with dried up ferrofluid could permanently damage the voice coils. I bought a pair of Kef Q10 that had that happen. I had to replace voicecoil and diaphragm myself. NT25 vc/diaphragm replacement is much harder to find than NT19. From my research, the only viable replacement I found was by using an Audax tweeter as the donor.

 

[Paddy Garcia]

Your 104s definitely need some service. Hard to tell from your pics if the woofers have foam (late) or rubber (early) surrounds. If foam they are surely dead and should be replaced before any use.

The tweeters need a ferrofluid change, and the difference will be night and day. Easy fix if you're the least bit handy.

The foam donuts in the middle also need replacing, but IMO failed donuts aren't dangerous. Donuts are an easy fix but require a good deal of disassembly.

Falcon makes a very nice set of capacitors. I've rebuilt two sets of 104/2s with them since I was disassembling to do the donuts. TBH didn't notice much difference and wouldn't do it unless there was good reason after the tweeters and foam fixes.

 

[Raynald]

Thanks a bunch. After looking closer they do have the colored rings. Covered with dust, maybe that's why I didn't see it but kind of obscure. If it weren't for you guys I still would not have figured it out. And I had them connected wrong too! For the record I have the metal ones in Raynald's 3rd link above.

Glad to be of service! As others have said, it sounds like Kef need work. In my experience the 104/2 was not to everyone's taste, none of the speakers I sold were regardless of price, but the vast majority of people were impressed. Rotted donuts are not dangerous unless some of the foam bits get into the voice coil in which case they can ruin your woofer.

 

[slimecity]

Yep - give priority to the ferrofluid first. I just got a pair and the tweeters sound great, so I suspect they don't need re-fluiding - Im not positive on this though.

If yours sound veiled with not great treble - then do this first. The tweeters should sound great.

Next is the woofer donuts - Mine have rotted away - but have rubber surrounds. If yours are the same, then there is a fairly major job ahead to redo these, but it will tighten up your bass. If your speaker surrounds have also rotted (some of these were made of foam) you should stop using them as they will sound terrible.

I asked a lot of people about redoing the caps - for the longevity of these Falcon caps, and comments from some who had done it that the return on sound was fairly negligible, I elected not to go ahead with this.

Even with these things to do - once I got these speakers home and hooked them up, I realised that they were the best speakers I have ever heard - I have heard many. If you don't get that impression then something is wrong.

Make sure you have plenty of power driving them too, and an amplifier that can handle a 4 ohm load.

 

[hwystar]

My replacement mid plate for the 710 came in today so, the first order of business is to get that going. I won't be using the KEF again until they are properly attended to.

 

[hwystar]

Looking into these a little further and I see rubber surrounds, good! The bass is not lacking by the way. I listened to the tweets with a paper towel tube and although they are working, maybe not as good as they should. One even sounds a little more not as good, maybe. I'm a little bit handy and I'm sure I could do the ferro fluid. Need to watch the video again.

The donuts worry me a bit. One in particular has started to crumble. I can't even see the top ones yet, (some disassembly required). If debris from the donut gets down into stuff, is it easily cleaned out? Like maybe with a vacuum? Just wondering.

 

[darkblue94]

Looking into these a little further and I see rubber surrounds, good! The bass is not lacking by the way. I listened to the tweets with a paper towel tube and although they are working, maybe not as good as they should. One even sounds a little more not as good, maybe. I'm a little bit handy and I'm sure I could do the ferro fluid. Need to watch the video again.

The donuts worry me a bit. One in particular has started to crumble. I can't even see the top ones yet, (some disassembly required). If debris from the donut gets down into stuff, is it easily cleaned out? Like maybe with a vacuum? Just wondering.

You want to prevent the foam fragments from getting into the coil structure, can cause damage.

 

[hwystar]

That's what I thought and I don't know if that's already happened or not. Should I throw some vacuum to it now and suck the old foam right out of there where I can see it beginning to fall apart?

 

[darkblue94]

That's what I thought and I don't know if that's already happened or not. Should I throw some vacuum to it now and suck the old foam right out of there where I can see it beginning to fall apart?

That wouldn't hurt anything and may prevent any damage from happening. The top woofer is facing downwards so no need to vacuum that one.

 

[Donkey Karma]

The KEF 104/2 speaker in proper condition is a fantastic speaker. To be in proper condition they must be restored. Foam surrounds and "donuts" need replaced, tweeters need the ferrofluid replaced and the crossovers need to be re-capped. The ADS 710's are real nice speakers but not up to the level of KEF 104/2's.

Please excuse the reviving of a flat lined post. I also mean no disrespect in pulling the quote, its purely for conversational/discussion purposes.

I have recently just completed a restore on a pair of 104/2's. Which included a full re-cap from the kef authorized Falcon Acoustics.

Every cap (over 30 if memory serves) I pulled tested well within specs of the 10% claim. Also almost all were within percentages of their replacements. I am usually a proponent of replacing electrolytic capacitors that exceed 20yrs old.

The replacement group from Falcon was +$80 plus the possible drag with customs. Not sure it was a good investment? Not saying it wasn't considering the original caps could have been ready to start taking a dive. Just food for thought of anyone thinking of performing a re-cap.

 

[darkblue94]

Please excuse the reviving of a flat lined post. I also mean no disrespect in pulling the quote, its purely for conversational/discussion purposes.

I have recently just completed a restore on a pair of 104/2's. Which included a full re-cap from the kef authorized Falcon Acoustics.

Every cap (over 30 if memory serves) I pulled tested well within specs of the 10% claim. Also almost all were within percentages of their replacements. I am usually a proponent of replacing electrolytic capacitors that exceed 20yrs old.

The replacement group from Falcon was +$80 plus the possible drag with customs. Not sure it was a good investment? Not saying it wasn't considering the original caps could have been ready to start taking a dive. Just food for thought of anyone thinking of performing a re-cap.

My understanding is that KEF matched their Reference Series crossover capacitors to a 1% or 2& tolerance to ensure a uniform result. Whether Falcon does this or not I do not know.

 

[Donkey Karma]

Could be? They are all 10%ers originals and replacements. Same brand and labels. I am guessing if I threw them all in a pile and you tested them all for value you would be pressed to identify the old from the new.

Wondering if Falcon uses new old stock? Some were of different make, maybe two 3 a xxover if memory serves.

Side note: Wasn't very impressed with FA. I recieved a random bag of caps jumbled together which was an incomplete order. Only one 3.3uf and one 19uf. Never replied to email. I know others sing their praises, based on that I would think my experience was the exception.

 

[Blue Shadow]

Interesting that the ADS sounded better than the KEF. But neither was in full, proper operating condition. Retail pricing on the KEF put them in the same category as the ADS 1590, about 2grand+ when new. Same era also. Wonder if the 1590 would win that comparison?

Anyway, be nice to hear back from @hwystar to know that the 710s improved with the plate he got from Richard and where he stands on the overall opinions and of course, the progress...thought process maybe for the rebuild of the 104s. Both these speakers are very well appreciated here on ak and have their place. I know for a bookshelf my 710s are a keeper.