How long a list would you like? Lots of diy ones round here as well. And says nothing of tweaking the amplfier you have.
dave
In my eyes, if there is a problem with your amp, @Eric Stockman amp, it needs new electrolytics and the switches cleaned. For the rest it is one of the classics, and powerful enough. In my experience restored amps of this vintage are a perfect pairing for the Concertos. I tried several. But their electronics need to be refreshed, and, at best, uprated (for a good idea on this see the work of user Leestereo over at Audiokarma). Then it becomes rather academic which amp brand to chose, most of the goldies sound great. But actually I'd suggest keeping the thread to the Concertos.
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My bad, wasn't thinking about that! LOL
Sorry for the late reply, I meant wool inside the mid driver compartment, not the reflex tube, on my Concertos they are tube like, earlier versions are rectangular. I'll try to post pics tomorrow of the inside mods, can't find them right now, basically I added bitumen pads to all sides (not covering the whole surface as I didn't want to add that much weight) felt and acustalix (kind of pillow fill) a la Troels Gravesen manner, besides adding some bracing at the middle of the cab and bringing forward the front baffle to make it flush with the sides, bear in mind they are KefKit3, not factory Concertos.
I built wood stands to get tweeters at ear level height... different approach to the small stands supplied with the beautiful Concertos @planet10 posted! My spikes don't damage to the floor, they sit on small round brass feet
I haven't taken the route of expensive interlinks and don't think I will... I made some with quality (yet still cheap) noisseles low capacity instrument cable for phono connects... maybe it's not the better choice, but I don't notice any faults!
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About modding cabs, as Dave suggested maybe it's better to build better ones from the start, but that's a lot of work and my main concern was crossovers to see if I was able to improve the sound of these guys... achived that I don't discard doing it, but not in the near future 😅
Thanks Marintz, pics are always appreciated! I'd love to see a shot of your crossover as well. Could you post one?
Your cabinets look great. KEF later used the partial bitumen pads covering on their better speakers. Those are also very well damped with foam. In the commercial Concerto (2nd version with external crossover) the tube for the B110 is tightly stuffed with a fat layer of foam. I'd have to look into my KIT version of the Cantata (which followed the Concerto) in order to check how well the builder stuffed it.
As to the observation, that the classic combination of T27, B110 and B139 is still relevant: Falcon offers a speaker with their reconstructed drivers, based on a transmission line design (and call them IMF 200 🙂. I think they look great and I would really love to hear them.
https://www.falconacoustics.co.uk/imf-200-completeathome-loudspeaker-system.html
I wouldn’t even consider someone else’s TL without knowing how they designed it. But Jerry has shown that these classic drivers still sell.
There are lots of Classic TLs that acheive varying amounts of performance, i would not build any of them. A buddy did build one of Scott’s push-push lines and it was stunning. I always had a soft spot for the B139. I would swap out the B110/t27 for A5.2/3 or tweaked FF85wk for improved performance (and bi-amp because i’m not good at passives)
https://www.t-linespeakers.org/projects/vProjects.html
dave
There are lots of Classic TLs that acheive varying amounts of performance, i would not build any of them. A buddy did build one of Scott’s push-push lines and it was stunning. I always had a soft spot for the B139. I would swap out the B110/t27 for A5.2/3 or tweaked FF85wk for improved performance (and bi-amp because i’m not good at passives)
https://www.t-linespeakers.org/projects/vProjects.html
dave
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Yes, the inner surface of my B110 tubes is also covered with foam, I filled the remaining space with yellow fiberglass itchy stuff and noticed an improvement, later changed it for lambs wool. When I got my KefKit3 cabs were all stuffed with fiberglass... I understand that's not good for ported speakers.
T-lines are always tempting! Without going that route still lingers in my head the possibility of building bigger Concertos, maybe deeper or making them floorstanders, but I think that would need a change in crossovers that is beyond me, anyway I'm satisfied as they're now... but what if? 😅
Here are the crossovers, they're big'n heavy, all Jantzen caps (Cross caps, Standard and electrolytics) resistors are flying in the air, I did what I could!
T-lines are always tempting! Without going that route still lingers in my head the possibility of building bigger Concertos, maybe deeper or making them floorstanders, but I think that would need a change in crossovers that is beyond me, anyway I'm satisfied as they're now... but what if? 😅
Here are the crossovers, they're big'n heavy, all Jantzen caps (Cross caps, Standard and electrolytics) resistors are flying in the air, I did what I could!
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Thanks Dave and Eschenborn. I guess they sound similar to yours, mine however are narrower, 37.5cm wide instead of 43, I would like to hear factory Concertos but seems I'm about 1800 km from Eschen!
Thanks again for sharing your schematic, I was about to get rid of my Concertos and crossovers saved them, they sound very good to me now
Thanks again for sharing your schematic, I was about to get rid of my Concertos and crossovers saved them, they sound very good to me now
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I ordered the speaker kit iirc in the 70s and built a set. My dad helped with the wood and wiring up the crossover. I enjoyed them for about a year or so but I thought the low and mid bass could deliver more especially for classical organ music which I was a fan off. At that time Chris Rogers Pro 9 TL got a bit of audio press attention so moved on to these. I only sold them about 5 years ago. A couple of the roll surrounds of the peerless midrange perished over those 40 odd years and one of the audax tweeters failed. I think nowadays what can be done with a modern smallish fullrange speaker in a small TL or bass reflex with a 2 watt valve amp is also amazing and musical so I’ve moved in that direction.
Look what I found under the Christmas-tree 
A package coming from Germany …
In the meantime they have found a place in my Concerto’s.
What a difference in sound!
All my CD’s and every type of music just sounds completely different.
What a revelation.
Seems like the Dire Straits play with different guitars now..
And how great a saxophone sounds now!
Also voices sound so much clearer now.
And the crash cymbals of a drum !
It is simply like the difference between night and day.
All these years , I thought my T27s weren't that good.
But now the tweeters DO sound as sharp as a razor blade.
Again : what a revelation !
I'm as happy as a kid in a candy store.
I can't get enough of it.
No more dull music.
No doubt about it : this modified ab-CO is like Tina Turner 's song : Simply the best !
Thank you so very much Santa Eschenborn!
A package coming from Germany …
In the meantime they have found a place in my Concerto’s.
What a difference in sound!
All my CD’s and every type of music just sounds completely different.
What a revelation.
Seems like the Dire Straits play with different guitars now..
And how great a saxophone sounds now!
Also voices sound so much clearer now.
And the crash cymbals of a drum !
It is simply like the difference between night and day.
All these years , I thought my T27s weren't that good.
But now the tweeters DO sound as sharp as a razor blade.
Again : what a revelation !
I'm as happy as a kid in a candy store.
I can't get enough of it.
No more dull music.
No doubt about it : this modified ab-CO is like Tina Turner 's song : Simply the best !
Thank you so very much Santa Eschenborn!
It's been almost a month now, since I installed the 'modified acoustic butterworth crossovers®Eschenborn', and every day I am still amazed by the new clear sound of my Concertos.
Yes, the Concertos were already good, but now they are TOP!
Enjoying them every single day#thankyouEshenborn.
Really recommended.
Yes, the Concertos were already good, but now they are TOP!
Enjoying them every single day#thankyouEshenborn.
Really recommended.
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Forgive a somewhat late addition to this great discussion. I own two sets of the 104.2 and can add a little on their use.
Both of my pairs are from what I believe (judging by serial numbers) is the last year of production. Both are bi-wire, rosewood cabs. I am collecting spare crossover and tweeters but have so far not noticed any degradation in sound so they have all stayed in the box. Ken Kessler in his book on KEF commented that the problem with the dried fluid in the tweeter was finally addressed - and that may explain why I have not noticed a need to have mine serviced.
The most remarkable aspect of these speakers that I've found is that sound quality is greatly improved with more power and highest quality power cords , speaker wire and XLR inner connects. I use Parasound JC1 Mono Blocks (800w 4ohms) to drive the woofers and a Parasound Halo Integrated to drive the mids and tweeters. The sound is very fast and the sound stage very 3-d in sound image. This is my fourth configuration. I worked my way up the power and cable expense step by step My cables are largely Audioquest and near the top of the line.
The end result is a warmth and sound stage which I have not been able to equal auditioning systems in local stores. Vocals are spot on and brass and percussion (including piano) are exceptional.
Both of my pairs are from what I believe (judging by serial numbers) is the last year of production. Both are bi-wire, rosewood cabs. I am collecting spare crossover and tweeters but have so far not noticed any degradation in sound so they have all stayed in the box. Ken Kessler in his book on KEF commented that the problem with the dried fluid in the tweeter was finally addressed - and that may explain why I have not noticed a need to have mine serviced.
The most remarkable aspect of these speakers that I've found is that sound quality is greatly improved with more power and highest quality power cords , speaker wire and XLR inner connects. I use Parasound JC1 Mono Blocks (800w 4ohms) to drive the woofers and a Parasound Halo Integrated to drive the mids and tweeters. The sound is very fast and the sound stage very 3-d in sound image. This is my fourth configuration. I worked my way up the power and cable expense step by step My cables are largely Audioquest and near the top of the line.
The end result is a warmth and sound stage which I have not been able to equal auditioning systems in local stores. Vocals are spot on and brass and percussion (including piano) are exceptional.
Even within the same company, over so many (20ish?) years you cannot go by specs, they are surely measured on a different setup. KEF were one of the vanguard of in-house measurement and simulation, and over those years the design capability increased much. I would expect the 104.2 to be a better design (though with your ears used to the Concerto you might not like how they sound right away). I'd definitely try a set. Then again I'd also recommend you try a modern set, with even more decades of development. And if you like bass, yes, a sub is revelatory BUT needs adjustable highpass and lowpass crossovers and maybe room EQ to achieve flatness. Not that subwooferless systems are flat either. Some outlets will let you home audition with reasonable return shipping and restocking fees (Crutchfield for one).
Hi, i have a pair of kef concerto speakers and a spare pair of original boards. I would like to try eschenborn's mods....could you advise on the parts needed? Many thanks.
Thanks eschenborn.... I have managed to find most of the components needed, but cannot find the following.
Audyn raw 100v 82uf
Expotus polyester 3.3uf
Expotus polyester 600nf
I am also not great at reading circuit diagrams so could not work out what sized inductor i needed as replacement.
Also what type /make of resistors are recommended?
Thanks for any help....I am based in the uk.
Audyn raw 100v 82uf
Expotus polyester 3.3uf
Expotus polyester 600nf
I am also not great at reading circuit diagrams so could not work out what sized inductor i needed as replacement.
Also what type /make of resistors are recommended?
Thanks for any help....I am based in the uk.