Modifying KEF 105.1- heresy? Or time to go modern?

[VanDerGraaf]

Guys and girls, this is a long post, hope you won't be too bored. I do need your help.


 

I've had my KEF 105.1 for 18 months now and they actually constitute my first proper hi-fi speakers (I can't believe I managed to live for so long with only some lowly Wharfedale Pi-40s!)

I suppose there are a couple of threads of thought on my mind. One is, how much I am/am not missing in terms of detail retrieval/resolution compared to a good set of modern speakers? I do find that the 105's are slightly reticent in the top octaves for my taste (and I do mean very slightly, I am not a brightness freak). They have been recapped already with Wilmslow Audio Supersound caps (hopefully if they themselves did it, they will have taken care with cap matching, as I know about the KEF Reference series caps being fastidiously matched to each individual set of drivers rather than using generic values).

In spatial/soundstage terms I think they are really still quite something. Holographic!

Recently I have been a little dissatisfied with the sound. The first nine months was the honeymoon, haha! I began to feel in the last while that on busy passages of mid-range information,  the sound somehow became slightly unpleasant. I've had a few other speakers through VanDerGraaf Towers, so it wasn't a priority to get to the bottom of it

After a check yesterday, it seems that one of the B110 mid drivers has some voice coil scrape. Bugger. Yes, I could get a replacement, but sp0157 variant of this driver isn't easy to come by. Plus, I'd imagine it would be better to replace as a matched pair.

So here is the question.

Would it be wrong to modify this wonderful design? I feel that i am unlikely to ever sell these speakers, they are just iconic and a design classic. They are also a firm favourite amongst friends (and indeed also my girlfriend) who love the "droid" vibe! So resale problems due to "authenticity" isn't an issue...

I know, I know, replacing those Bextrene drivers with something else will change the sonic signature a bit. I am not precious about this though. I wouldn't even be precious about the T52 tweeters going either. I'm thinking about an RFC-type modification here. Something that looks the same but sounds bang up to date. As I said, they are pretty much holographic enough in my opinion, the imaging is brilliant and they can cast a big soundstage.

The other idea is to go for something more modern to replace these as my main listening instruments. Something that would show the 105 a clean pair of heels in all departments.

Some pertinent info:

My room is about 6.5 metres by 4.3m, I listen along the long wall at a distance of about 2.5 -3 meters (does that make me an Audio Physic candidate? )

I think I like a reasonably forward presentation but not completely in-your-face...sort of iron fist in velvet glove "when needed", to paraphrase. Warm, yet with detail and speed. Emotion. I don't want "hype".

I like larger scale to the presentation (as a musician, you get used to the acoustic "size" of sounds of instruments and, frankly, a bit expectant of hearing it).

Here's the thing: I am not a loud listener. I seriously doubt if I ever go over 90dB in listening. I value my hearing. Most of the time I would think it is more like 60 to 75 (at the listening position).

I listen to everything, favourites would be prog rock, classical of most types, electronic music. 

Lastly, as my 105 ownership might indicate....I don't really like conventional  "tower" shape speakers that much. I don't mind them, but unusual shapes and designs really get me enthusiastic. Mind you, just a sloping front like say, a Rega Ela, or a lovely Sonus Faber curved side,  is enough for me to be happy. Just not such a fan of the conventional (boring) tower thing. No WAF problems with anything either (I'm a lucky man).

Money...obviously less is better....but I would probably be prepared to spend up to 2k-ish. 

All offers of help and advice most welcome!! (Please )

Rohan

 

[bandit pilot]

That's a great introductory post.

To keep things simple, as it seems a slightly rubbing VC is the cause for this thread above anything else, have you tried rotating the offending unit through 180 degrees to see if the problem persists? By that I mean taking the driver out and turning it upside down. It's not beyond possibility that the magnet could have moved very slightly over 40 odd years, and the bg heavy speakers are more likely to take a hard landing at some point in time.

105's are another fave of mine. I'd be loathed to change anything about them.

 

[eastone]

Get in touch with Paul at RFC. I have been corresponding about making changes to my KEF 103.2 and he is very, very knowledgeable...

 

[SergeAuckland]

That's a great introductory post.

To keep things simple, as it seems a slightly rubbing VC is the cause for this thread above anything else, have you tried rotating the offending unit through 180 degrees to see if the problem persists? By that I mean taking the driver out and turning it upside down. It's not beyond possibility that the magnet could have moved very slightly over 40 odd years, and the bg heavy speakers are more likely to take a hard landing at some point in time.

105's are another fave of mine. I'd be loathed to change anything about them.

This is definitely worth trying. It affects bass units more than midrange units, but it could just be the solution.

The only modification I would ever make to the 105s is to make them active, and keep the original crossover to put back if you ever want to sell them.

I had a pair in the mid 1980s. Lovely. If I hadn't got my 801s, I would have had a pair of those again and made them active.

S 

 

[Beobloke]

If you like them, then stump up for the new drivers and enjoy them. Don't mess about with the them, though. They're a classic design and many people (including me!) like them just as they are. If you want a change of sound, then take a deep breath, sell them and move on.

 

[graham67]

Get in touch with Paul at RFC. I have been corresponding about making changes to my KEF 103.2 and he is very, very knowledgeable...

I second this, I have RFC refurbed JBLs from the 70s and love the sound they make, no question they still sound authentic, but without any of the tiredness that can afflict 40 yo speaks.

 

[oldius]

Great speakers. Leave well alone. Rotate the drivers and if recapping, like for like only.

 

[eastone]

Paul will sort these taking great care to preserve the original character as far as possible - especially important given you may need to look for alternative drivers. He is well aware of KEF's attention to component matching and computer analysis techniques...

btw, bet these sound ace - I love my 103.2s... holographic is the word...

 

[ff1d1l]

Beyond rotation, there is a hairdryer solution discussed on AOS, with success claimed beyond simple driver rotation. Might work better with mids, where the cone weight is negligible and not so likely to sag back into place.

For what its worth, I'd counsel keeping originality too.

If you're dissatisfied with the sound, you might try subbing in different electronics upstream - these should be capable of being got to sound very good.

 

[rabski]

They're not my favourite speakers, but no way would I suggest modifying them. They are what they are, and are good at that.

Start messing around with crossover frequencies and all the rest, and you'll end up with something worse than you started with.

If they don't suit, change.

 

[uzzy]

Guys and girls, this is a long post, hope you won't be too bored. I do need your help.


 

I've had my KEF 105.1 for 18 months now and they actually constitute my first proper hi-fi speakers (I can't believe I managed to live for so long with only some lowly Wharfedale Pi-40s!)

I suppose there are a couple of threads of thought on my mind. One is, how much I am/am not missing in terms of detail retrieval/resolution compared to a good set of modern speakers? I do find that the 105's are slightly reticent in the top octaves for my taste (and I do mean very slightly, I am not a brightness freak). They have been recapped already with Wilmslow Audio Supersound caps (hopefully if they themselves did it, they will have taken care with cap matching, as I know about the KEF Reference series caps being fastidiously matched to each individual set of drivers rather than using generic values).

In spatial/soundstage terms I think they are really still quite something. Holographic!

Recently I have been a little dissatisfied with the sound. The first nine months was the honeymoon, haha! I began to feel in the last while that on busy passages of mid-range information,  the sound somehow became slightly unpleasant. I've had a few other speakers through VanDerGraaf Towers, so it wasn't a priority to get to the bottom of it

After a check yesterday, it seems that one of the B110 mid drivers has some voice coil scrape. Bugger. Yes, I could get a replacement, but sp0157 variant of this driver isn't easy to come by. Plus, I'd imagine it would be better to replace as a matched pair.

So here is the question.

Would it be wrong to modify this wonderful design? I feel that i am unlikely to ever sell these speakers, they are just iconic and a design classic. They are also a firm favourite amongst friends (and indeed also my girlfriend) who love the "droid" vibe! So resale problems due to "authenticity" isn't an issue...

I know, I know, replacing those Bextrene drivers with something else will change the sonic signature a bit. I am not precious about this though. I wouldn't even be precious about the T52 tweeters going either. I'm thinking about an RFC-type modification here. Something that looks the same but sounds bang up to date. As I said, they are pretty much holographic enough in my opinion, the imaging is brilliant and they can cast a big soundstage.

The other idea is to go for something more modern to replace these as my main listening instruments. Something that would show the 105 a clean pair of heels in all departments.

Some pertinent info:

My room is about 6.5 metres by 4.3m, I listen along the long wall at a distance of about 2.5 -3 meters (does that make me an Audio Physic candidate? )

I think I like a reasonably forward presentation but not completely in-your-face...sort of iron fist in velvet glove "when needed", to paraphrase. Warm, yet with detail and speed. Emotion. I don't want "hype".

I like larger scale to the presentation (as a musician, you get used to the acoustic "size" of sounds of instruments and, frankly, a bit expectant of hearing it).

Here's the thing: I am not a loud listener. I seriously doubt if I ever go over 90dB in listening. I value my hearing. Most of the time I would think it is more like 60 to 75 (at the listening position).

I listen to everything, favourites would be prog rock, classical of most types, electronic music. 

Lastly, as my 105 ownership might indicate....I don't really like conventional  "tower" shape speakers that much. I don't mind them, but unusual shapes and designs really get me enthusiastic. Mind you, just a sloping front like say, a Rega Ela, or a lovely Sonus Faber curved side,  is enough for me to be happy. Just not such a fan of the conventional (boring) tower thing. No WAF problems with anything either (I'm a lucky man).

Money...obviously less is better....but I would probably be prepared to spend up to 2k-ish. 

All offers of help and advice most welcome!! (Please )

Rohan

If you don't like em find summat you do and change them.  If you modify them then you will not see a return for your money and to be honest most diy modifications to loudspeakers are a disaster as people do not have the measuring equipment to make the necessary changes without affecting everything about the loudspeaker usually in a bad way.  In fact it could wipe a load of value off your loudspeakers when you come to change them.

Your power amp and pre are not the problem here .. time to look for your next loudspeakers methinks    

 

[ff1d1l]

You could go active with Behringer kit...Greybeard had some Kef based home builds at Scalford with a Behringer active crossover and their amps too. A really excellent sound....and you could of course easily reconvert to original condition should you wish to sell at a later date.

I believe the Behringer kit was not expensive....

 

[greybeard]

The 2 amps and active crossover cost a measly £480   and thank you for your kind comments.

Oh you would need one more amp so add approx. £150

 

[eddie-baby]

You could go active with Behringer kit...Greybeard had some Kef based home builds at Scalford with a Behringer active crossover and their amps too. A really excellent sound....and you could of course easily reconvert to original condition should you wish to sell at a later date.

I believe the Behringer kit was not expensive....




 

These power amps do look interesting and they are getting a lot of praise. Wouldn't mind trying one at home one day.

I would imagine there's probably more industrial (as in non domestic specific) bargains out there as well.

 

[moo-fi]

Getting less so Eddie, too many active speakers.  I have a few Crown lumps, a number of MC2 amps (16 at last count) and a rack of full fat audio amps, all sound half decent.  A QSC I acquired was pretty rough though, even if the specs where good.  Always deals on a well known internet site, MC2 half superb back up and so does Behringer in my experience with X32 mixers.

 

[greybeard]

The Behringer A500 has no fan for cooling, unlike a lot of Pro Audio gear, so is more suitable for domestic systems.

 

[eddie-baby]

The Behringer A500 has no fan for cooling, unlike a lot of Pro Audio gear, so is more suitable for domestic systems.

Oh no, even more reasons for me to buy/try one 

Can they be bridged mono as well for more power. Not that I've had much experience with bridging amplifiers but it sounds like fun. Whether it changes the sound I'm not sure. 

 

[SergeAuckland]

Oh no, even more reasons for me to buy/try one 

Can they be bridged mono as well for more power. Not that I've had much experience with bridging amplifiers but it sounds like fun. Whether it changes the sound I'm not sure. 

Yes, bridging is provided as standard. The only issue with bridging is that each 'half' of the bridge sees half the impedance of the loudspeaker, so if using a 4 ohm loudspeaker, each side will see 2 ohms. Whilst the A500 will drive 2 ohms, it will tend to run rather warmer than normal. I would prefer to use the A500 bridged only into 8 ohm 'speakers.

I use mine unbridged, as 120 watts per channel is quite enough.  As to sound changing, it shouldn't change anything much except doubling the output impedance, but that's pretty low anyway. Distortion won't change, nor will frequency response.

S.

 

[Fatmarley]

Could be worth a try - Walpurgis driver fix