KEF 105

[Jac Hawk]

Hi guys, I’m thinking about getting a pair of 105, but have heard that the bass drivers can be a bit iffy, some advice on what to look for and what model to go for would be appreciated thanks

[VanDerGraaf]

Hi Mike,

I'm guessing what you are referring to it the chance of the bass cones sagging. I've heard of this happening but don't really know what it looks/sounds like if it does happen. I've had 2 pairs of 105s (still have the second pair) and not had this issue as far as I am aware- the low end has never sounded anything other than deep, controlled, and I have never heard anything that sounds amiss.

What speakers are you running currently?

As to which model...well, the original 105, and 105.2 are very similar. The head of the 105.2 is plastic rather than mdf or whatever the earlier ones are made of. Both feature the same 1" T52 tweeter, 5" B110 mid and 12" bass driver (which may be slightly different on each as there are fewer mounting points on the .2).

Specs between these are very similar. I think the .2 and the .4 mentioned below both have the S-stop speaker protection system which prevents damage from amp overload.You don't need it though...they all take a lot of power easily.

The 105.4 is a smaller model with the same head assembly and 2 8" drivers instead of the single 12"- could be a good call with a smaller room. Having said that, I have heard the 105.1 in a small room, of say 10x12 and it still worked. I have them in my 20x14.5 living room on the long wall and they work so well there too. I actually think they are extremely versatile and work well in near/mid/far field.

Bass with all is deep, tight and not boomy as we are dealing a with sealed box design. I think this is why they are versatile as regards room size.

If you look up Kef Museum you can see pictures and specs for all of these.

The 105.3 is something else altogether and bears no relation to the others. It's a more typical floorstanding shape with the hidden vertically-aligned bass drivers that became a KEF trademark right through to the Reference 1/2/3/4 types in the late 90s. Supposedly a brilliant speaker but I have never had the pleasure of hearing them.

[Jac Hawk]

Cheers Rohan, just the info i needed:thumbsup:

[Spalmgre]

I have had my Kef 105 (first version that did not use .1 or any thing else) since new. They are very nice as the sound stage is very wide. The base is tight but you can sometimes feel that there is not enough.
This is not however the case it is just that the base is not bloomy at all. But you might consider a small sub woofer as part of the system. This depends on your taste and music choice. I have never used one.

I have also heard that you might need to turn the base driver and I have done so. But I have never felt anything that suggest that my drivers sagged over time.

[VanDerGraaf]

Thanks Stefan, I had never quite realised where the lower crossover was placed until I saw your picture.

Regarding the low end, I think they need the wick turned up before they start singing down there. Once you do that though....there is plenty! Very well-balanced with the rest of the frequency range.

Playing something like Genesis' "Trick Of The Tail", the bass pedal notes can easily pressurise my 6.5 x 4.5m room.

[Spalmgre]

Kef 105 has different crossover versions. My speakers that are the first version already has not all components in all possible places. So you might argue what is the right crossover layout. But what you see in my pictures is what my speakers come with. The caps are new.

I attach some crossover versions. The one with red, green and blue text and lines shows the setup in my speakers. I have added the color text and lines. L6 surprises me so maybe you like to comment.

The active schematic is one that I have found when searching for info about Kef 105 on forums. I did build something similar 40 years ago for my JBL monitors. Now I have used miniDSP and Najda that I find much better for tools for bringing out the best from these classic speakers.

[Maggusch]

Hi,
thank you for your XO uploads. I also have a Kef 105 (the first version). I guess you have used the recap-kit which is offered by falcon acoustics. What was the sound like after the recapping?

I´m considering to do the same but have to look in my networks for existing parts.

[VanDerGraaf]

I recapped mine earlier this year using a Falcon kit, I did however use a Mundorf M-Lytic in the tweeter section instead of the Alcaps.

Have to say initially I didn't hear a lot of difference from what I remembered, but after a while the sound seemed to get a bit clearer and overall I would say there was less "hash" in the sound- definitely an improvement. Worth doing, probably more fiddly than in many other speakers due to opening up the head section.

I didn't do the bass section recap.

I still think this speaker has untapped potential- maybe needs a lift/improvement above about 8-10k. One of these days I will end up adding a supertweeter, but I am almost afraid that then I will never want to buy another speaker...

[Maggusch]

Ok thank you for sharing your experience.
I have 2 pairs of Kef 105. One pair is the original first version. Impressed by the sound and the cool design I bought a faulty 105.2 version. I sold all the drivers and refitted them with a 3 way design I had known by Kef fans, who developed a 3 way design (but with modern drivers) derived from the C90 (DIY KIT) same drivers as the 105.2. It uses a Monacor SP 300 KE. This driver works very well in the cb 105 cabinet with 70l. As the cross over frequency of the new designed 3 way (the B110 and the TI52 had been replaced by Dayton professional drivers) to the midrange were also in the 400HZ region, I tried to exchange the heads (105.2 withDayton to 105 original). I must say the Monacor (around 86db, 40 Hz -3db) fits very well to an original 105 heads. I am sure that replacement is much better than the Peerless driver which is suggested to replace the Kef B300. The Peerless might be similar in Kef 300 specs (concerning a dropin in the original network) but has a higher resonance frequency and lower bass quality.
The Monacor sounds similar to the B300 but is much faster and more accurate (Keflar). I also made a side by side comparison between the different heads and the XO-designers made a very good good job in copying the tonal balance with the same roll off as the Kefs. They sound very similar.
But it also becomes obvious how good B110 and T52 do their job. I would not suggest to pair them with a super tweeter, cause if you have a good and clean amp, everything is there.
If you are interested in going with the Monacor, just write me a PN.

Attached 2 pictures of the Kef 105.2 bass cabinet (with different frontplate to fit the Monacor) with the 2 different heads
https://i.ibb.co/55jwWv7/IMAG3481-2.jpg
https://i.ibb.co/jfByrxT/IMAG3482-2.jpg

[Mikeandvan]

what is the sonic signature of these? I think my An Js are a bit too revealing for me, I need something more forgiving of rougher recordings.

[fatmarley]

I like this guy here. He's not the most professional. It's more like chatting to some guy down the pub or at a bake-off, but at least he's giving an honest opinion (I trust the more professional Youtube reviewers as far as I can throw them).

https://www.youtube.com/watch?v=_i-4QfHcbYM

[Maggusch]

Hi Mike,

the sonic of the Kef 105 is a round and full sound. So more on the warm side than analytical. This is achieved as the frequency response has a roll off
towards upper midth and highs and is not flat.
But as I said you won't miss anything as imaging and details are very good. The T52 Tweeter doesn't sound harsh but smooth. Is it too smooth, no. I also checked out a Celestion SL12si and their sound is even much smoother in comparison.
But I guess that your AI amp could be a bit too weak
to drive the Kefs. This is a Linkwitz 4th order network.

I heard the Kefs with a Mission Cyrus 1/2, Musical
Fidelity P170, MusicalFidelity Avalon, Croft 7r and a Quad 405MK2/520f. They all were able to handle it.
If you prefer tube amps I would guess a Lectron JH 50 would be a perfect match. But this is not a cheap solution. You could give it a try as tube watts a more powerful than tranny watts.

I like this UK-youtuber, too. ;)

[Mikeandvan]

Hi Mike,

the sonic of the Kef 105 is a round and full sound. So more on the warm side than analytical. This is achieved as the frequency response has a roll off
towards upper midth and highs and is not flat.
But as I said you won't miss anything as imaging and details are very good. The T52 Tweeter doesn't sound harsh but smooth. Is it too smooth, no. I also checked out a Celestion SL12si and their sound is even much smoother in comparison.
But I guess that your AI amp could be a bit too weak
to drive the Kefs. This is a Linkwitz 4th order network.

I heard the Kefs with a Mission Cyrus 1/2, Musical
Fidelity P170, MusicalFidelity Avalon, Croft 7r and a Quad 405MK2/520f. They all were able to handle it.
If you prefer tube amps I would guess a Lectron JH 50 would be a perfect match. But this is not a cheap solution. You could give it a try as tube watts a more powerful than tranny watts.

I like this UK-youtuber, too. ;)

Thanks Marcus, sounds like it might be worth my while checking these out, I don't mind buying a mid price decent SS amp to do that.

[VanDerGraaf]

Mike, I know you had a JVC AX-Z1010 (don't know if you still do) and that amp drives the 105 well.

They do however love TONS of power behind them- I remember an old Aragon 4004 really got them shifting.

[Mikeandvan]

Mike, I know you had a JVC AX-Z1010 (don't know if you still do) and that amp drives the 105 well.

They do however love TONS of power behind them- I remember an old Aragon 4004 really got them shifting.

No that one's long gone, found it a bit clinical.

[VanDerGraaf]

No that one's long gone, found it a bit clinical.

Funnily enough me too....had a loan- very good but there was a "greyness" to the tone I couldn't quite get past.
Anyway on with the 105 talk!