KEF 103.2 crossovers : are they original

[Jpkwd]

HI, I've got a pair of kef for which i just finished rebuilding the enclosures
Sanded and refinished them since they had some pretty deep scratches

Result is too dark in my opinion but they look nice

Anyway, the question :

checked the crossover and i am wondering if they are original
I think they are, perhaps a later version since the caps appear pretty recent (not the back ones i'Ve seen in other threads).

Serial 7118 rev B, paired speakers as seen on the back plate

Wondering if they could have been rebuilt.

What's your take on this ?
Thanks
Jpkwd

 

[macgolf]

Here's a pic of a crossover in my 103.2's s/n 12533 A & B. Looks like one of the 300 mfd Alcaps may have been replaced. Like you I've seen pics of various versions of crossovers in these speakers. How do they sound to you?

 

[Jpkwd]

Nice to meet you Macgolf,
thanks for the pic of the crossover. I think you are right : one the cap might have been replaced, perhaps the other one with the paler blue color too, but that one seems to be an alcap with the proper tolerance (+10%). The grey one i agree seems to be a replaced cap on both crossover with a +- 20% tolerance.

here is a thread that i looked at, which i think refers to the same caps i think (also the replaced one) - http://audiokarma.org/forums/index.php?threads/kef-103-2-wheres-the-bass.738245/

"The 600uF in series with the woofer is essential for the correct operation of the protection circuit, but it also extends the low frequency response by its interaction with the inductance in the woofer equivalent circuit, due to the driver/box suspension. The cut-off frequency is reduced below the box resonance and the roll-off below cut-off is increased from the 12dB/oct of the closed box to 18db/oct, which is still less than a reflex design. There is an equivalent effect above resonance as the series inductance of the woofer crossover becomes large. The crossover inductor interacts with the capacitance due to the mass of the moving parts, which produces a peak in the response, with a corresponding drop in impedance, in the region above resonance. The only way to avoid this it to have impedance compensation networks across the woofer to make it look resistive."


Now to your question : how they sound... not easy to describe but I can give it a try :

I just moved from a pair of bose 601 series ii driven by a sansui au-9900. I am juggling with the sansui to find a good speaker match. Found the kef lately. I'm studying them currently.

Before the sansui i had a Harman 330 B with Dynaco a25. - this setup has a tone. definitely limited in terms of bass (not a 30hertz adapted kit perhaps), but it has a tone. I love that. Must be something with the paper cone and sealed enclosure + cap coupled amp stage of the 330b. the kit has a definite resonance, which sings to you, you can definitely listen to that tone for hours. its like a bass (the instrument) with a familiar tone, fender pbass type tone through ampeg b15 say. Thumping type of bass. I really like that.

The kef are not like the a25/330b combo i think.They are still pretty new to me, yet i feel already that some material/vinyls sounds like crap through them. perhaps they are too revealing i don't know. Some recordings realllly sound like crap maybe i am learning that now.
the Kef woofer is something else in particular, more flexible, definitely say more ampeg SVT type tone.
Mid range is way more present on the kef than the bose.
i think, i'm never sure, that Bose 601 now sound like a deep deeep bass with very crisp trebles compared to the kefs, Bose might be missing the mid range that brings life to human voice on the kef.i have to admit i am listening to slow paced electronic music with dialogs in it, and i hear voice that are lifelike. Clear.

But the kef sound also a little dull currently, which i think could be related to aging capacitors. not sure,i think i will recap the xover just to see if that makes any difference

Now all that being said : how does your sound ? ( and my apologies if my description is not clear, it's so tough to clearly express what i hear)

Jpkwd

 

[macgolf]

@Jpkwd

Your descriptions of them are very similar to mine. My listening environment is an 11" x 13' carpeted room. I find them to have a wide sound stage, so that is a plus. To my 57 year old ears they are a little more balance, meaning less bright on the upper mids and highs. I prefer a more crisp and forward speaker in those areas so the Spendor Preludes,(another 8" British Monitor speaker I picked up at the same time), get more playing time. In my room the 103.2's do respond to even minor changes in room placement. They don't play as well with my lower power units. I also find they need to be played louder than my other speakers to sound right. that gets tiring quickly.

If I had purchased these new, and listened to 80's rock at a higher volume than I do now, they would be awesome. My listening preferences now lean heavily to 50's/60's jazz at around 60db with 75bd peaks. With the cooler temps and windows closed those numbers drop. Keep experimenting with room placement and you may find that "aha" moment when everything comes together.

KEF used ferrofluid in many of their tweeters in those days, but your 103.2's should not be one of them. I haven't recapped mine and read some threads that recapping didn't produce much notable improvement. I'm still on the fence about whether I will recap these. Experiment and enjoy!

If you're comfortable doing so, post some pics of your refinished speakers.

 

[Raynald]

Correct, the ferrofluid was used in the T33 MKII which you will find in the 103.3, not the original found in the 103.2.

Fantastic speaker, nice find.

 

[Jpkwd]

Thanks for the feedback, really helps to understand these new kefs,
i need to get accustomed to them.
There was a pair of 105.2 for sale locally (1000$): decided to wait till i wrap my head around the kef sound, compared to other speakers.
I still feel a little weird from not buying them, might be the only time i see these pass by. Well, perhaps not. Who knows. They are funny looking to me. 107 look better. More expensive. but again, might be worth it. I'll see, i hear B&W have very comparable speakers to the kefs.


For now, i got the 103 and i will listen to them closely. i like them. Good point on positioning the speakers. i'm experimenting currently in a 10X10 room without carpet, wood floor.
Here are some pics, sorry for poor quality : photography isn't my trade

You'll see in the photo my bose also, and a weirdo in the back overlooking the two speakers, it's an old leslie 147.



I also built some stands out of teak wood, not too bad looking for me.
(left-overs wood from when we've redone the wood floors at home). i taught re-using old wood was in the spirit of reviving vintage speakers

I'll recap them, just for the fun of it I'll let you know if it made any difference. I ordered the kit from falcon acoustics.

 

[Jpkwd]

Correct, the ferrofluid was used in the T33 MKII which you will find in the 103.3, not the original found in the 103.2.

Fantastic speaker, nice find.

Thanks for confirming that the 103.2 tweeter don't run on ferrofluid, makes one less thing to repair !

 

[macgolf]

Great job on the speakers and stands! While you're waiting on the caps, you'll have time to get accustomed to their sound pre-recapping them. I look forward to your impressions after recapping. From my reading, Falcon Acoustics does a great job matching caps to as close as possible as the factory did.

btw - Nice organ speaker.

 

[Jpkwd]

Thanks macgolf, i'll report back once i receive the xover kits

 

[Jpkwd]

Listening to the kefs
they're growing on me.
Fantastic mid ranges. i'm impressed. Great job on imaging and especially voices.

The AU-9900 has plenty of power to drive them. That i think helps, they appear like hungry little speakers.

I did improved on bass reproduction a lot and you were right Macgolf they are very sensible to room placement. A minor shift in placement or toe in has a very perceptible effect on bass.

i'm thinking, while i wait for the right set of Kef to come by again (105), i might experiment with a sub to get an improve response down to say 20hertz.
Even introduce a crossover to have a smooth transition between the sub and the kefs.

not exactly sure how i am going to work this but it sounds like fun to me. Any advice welcome

Would you have a suggestion on a decent sub that would fit nicely with the kef ?

I like well controlled bass like the one i hear on the kef, not a fan of vague muddy bass at all
Sealed box design subwoofer i think would be more to my taste, giving more tight and punchy bass


Jpkwd

 

[Jpkwd]

Received the kit to rebuild the crossovers
Why do i have so many projects ongoing ?
I'm enjoying the speakers as is for now, the rebuild will have to wait
I'll still report the findings here

 

[TomBig58]

Unlike you I owned the 105.2's before the 103.2's. I've had them for only a few months and they are some pretty special speakers. Beware they like a lot of power. Clipping my 100wpc Adcom I would have given them more if I could. I don't need that much power that often but if I have the speakers to take it.... Plus they are HUGE and I live in an apartment. Anyway, just a couple weeks ago the 103's came available and when I auditioned them from a very conscientious owner who took very good care of them and really knew his stuff I was blown away and grabbed them. I honestly thought the 103.2's sound good enough that I might not need the monstrous 105's. Let me tell you they come surprisingly close. Read the opening paragraph from the comments section in this review...yeah, it's like that!

http://www.hifi-classic.net/review/kef-model-103-2-327.html

So another pair of pretty beat up 103.2's came along at the right price just today and I decided to get them if for no other reason than for the replacement drivers. Although they sound nearly as good as the minty ones there's a couple of cone repairs I'm not thrilled about. They are going into the office for now while. The 105's were recapped with Falcon Acoustics parts from the previous owner and I might play with the x-overs on the beat up pair of bookshelfs if I get a mind to.

The 105's were purchased from an AK'er. Here they are in a previous life, post #34 MrChisox. http://audiokarma.org/forums/index.php?threads/the-official-kef-105-owners-registry.582663/page-2 Haha I'm a White Sox fan too!

I also own a pair of KEF T101 SP3744 little surround satellites I picked up for next to nothing on CL. Using them for rear surrounds. Not much there for what they ask retail for those little pups IMO. I guess I'm a KEF guy now

Still a work in progress I will continue to play with the KEFs until I make a decision whether to unload the 105.2's or not because of their size. For a short while I had a Premier Acoustics 10" sub running with the 105's not being sure if they really needed it. I can't wait to pair it with the 103's. It looks real nice with the woodgrain side panels and acrylic top as well. Front controls too! So pretty I'll probably never get rid of that sub. One of these days I'll stop mixing and matching and settle in to just listening, maybe...

 

[Jpkwd]

Hi there Tom,
Interesting response. I can definitely relate to your situation.
Before buying KEF 107, i stumbled upon the 103.2. Actually, the 103 got me hooked on the kef sound.

http://www.hifi-classic.net/review/kef-model-103-2-327.html

I had read the review before going for the 103. I see that you have a similar opinion. Honestly, from a low mid, mid and high perspective. I think i agree with this review too.
103 have a very distinctive sound which relates to the 107 too. As far as bass goes, 107 have a very distinctive sound if i can say it that way. very very low bass, compared to the 103.
That being said, some 1960 music doesn't benefit at all from the 107 bass range. 103 are absolutely perfect for a lot of music i listen to. Which got me in buying new caps in case something goes wrong with the 103, or to rebuild the xovers.

Sometimes, the bass range is needed. Very low upright bass songs, say in some passages of herbie hancock mwandishi (that comes to mind right now, or the intro in the dark side of the moon, or some electronic music) really need the bass extension.
Which led me to think of pairing a sub with the 103. I see you have a great sub, which, from my reading, would work well with an external crossover dividing the frequency range between the sub and the 103. That appears to be the best solution from my reading, and also would improve the 103 woofer performances. I agree the 105/107 are big speakers. Not always easy to work with them in smaller spaces. But hey, nothing's perfect. the 107 i have are in a smallish room. I still enjoy them a lot.

What's your take on the protection circuitry in the 103 ? Would you recommend bypassing it ?

 

[Hawkeye83]

Glad to see some more KEF guys here! I too got hooked by the 103.2. After them, I HAD to have the 107's, and I do. I also have LS50's. I've owned Quads, Apogees, Bozaks...the KEF's have stayed. Not saying they are "better"...every speaker has pros/cons...but I found them to my taste "all-around." I re-capped my 103.2's and haven't listened to them in awhile as I've downsized to one system. I recently sold mine to another AK'er and I'm waiting for him to pick them up. I should pull them out and give them a final listen!

I completely agree with you guys on the outstanding performance (especially relative to their used price) of the 103.2's. And on the 107's having the same character...just with more/special bass. It's so fluid, fast, and powerful...crazy.

So the 103.2's are sold so now the decision is 107 vs LS50. Not an easy one!

There are others here who may comment on bypassing the protection. I personally did not bypass but I think some here have.

I should open a KEF museum or start an enthusiast group or something...

 

[Hawkeye83]

I should open a KEF museum or start a support group...er, an enthusiast club or something...

Listening to the 103.2's now. Dang, they are nice!

 

[TomBig58]

As I was typing my post I was wondering why didn't I just put over in British Audio/Kef Owners forum but the ball is rolling, so...

I'm relatively new (6-8 months) getting back into hi-fi after many years of being content listening to 2ch vinyl, radio, and cd's through my AV system. Everything is still in flux for me as far as setup, placement, equipment. etc. An early purchase was a 2 input/4 output speaker selector with volume controls just so I could real time compare speakers. As much as I like the Kefs for critical listening (the 105's are first speakers I've owned that sound best to me tonally flat) when I want to rock the house I find myself liking to add in my vintage Infinity Qb's, amt's, or even the Nova 7's for a "fuller" sound. Both of my sources handle the multi speaker load just fine.

I agree that some older rock musicthat might have been mixed/engineered a little "muddier" sounds just that way through the 105's whereas through the Infinitys it sounds a little more "normal" to me. Maybe it's muscle memory but I noticed it again just the other day listening to an old Cream LP. I do, however know that those 103's aren't going anywhere but to my heirs.

I've cranked the 103.2's pretty hard and never had them go into protection that I know of so I havn't considered bypassing it.

Cheers everyone!

 

[Jpkwd]

Now that is an interesting statement to me :

some older rock musicthat might have been mixed/engineered a little "muddier" sounds just that way through the 105's whereas through the Infinitys it sounds a little more "normal" to me

didn't happen with the 103 yet, but at first listening with the 107 someone visiting who never listened to the 107 had a similar opinion. 107 were "too analytical" to use his own word. Didn't help i was playing a LP that was one of his favorite and listened to frequently on his system.

KEF can sometimes be unforgiving. that can be probably good or bad.

A good point is that it got me to understand t that "types" of mixes vary greatly in time and tend to be tied to a time period.
1990 mixes tend to sound thin, missing low mids sometimes. Not all records, but i've noticed it on a couple of instances. Sailing the sees of cheese, primus, is one of those cases, as an example of the mixes i hear from the 90s.

i might be totally off on that last statement. Really is new to me.

 

[Jpkwd]

such a long time for me to get to this job...but hey, never too late.
So i'm starting the rebuild of the crossovers. pulled one crossover out today, only from one speaker. i'd like to do an AB test.
All will be rebuilt with Falcon acoustic alcap kit.

Currently looking for the schematics to have a better look at where i stand.

Speaker A : Factory. Noticed one speaker when cranked was going into protection mode. I kept this one intact to compare with the rebuilt one.
so speaker B, in work :

so far
Noticable trace erosion. This will be an easy fix but still good to mention for posterity.


The rest of the crossover traces are ok from a rapid check



I am wondering if TF1 is in a good state or is displaying heat damage, or aging. Appears to be inflated. not sure yet what this component is.
Might still be in its original state, Not sure.




feedbacks welcome

hope everyone is doing fine.

 

[Jpkwd]

Here is the schematic i have so far

 

[Jpkwd]