KEF Concerto, any good? [Archive] - The Art of Sound Forum

DarrenHW

13-04-2015, 18:03

Stumbled across a pair of these beauties today which I believe are Kef Concertos?

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5043_zpsuvofzo1y.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5043_zpsuvofzo1y.jpg.html)

I've plugged them in, they seem to work okay and sound pretty decent. They have some sort of additional tweeter in the top left that's not on any others I've seen images of. They're very rough and have had a "custom" re-wire. To make it into the lounge they'd have to displace the Ditton 44's so my question is, are they worth the time?

struth

13-04-2015, 18:20

Very good speakers those although not seen them with the wee plastic it top left.. had a 5” bextrene mid driver . Depends whats been done to them of course

walpurgis

13-04-2015, 18:30

Yes they're Concertos. Not sure why yours have had what looks like a 'ring' horn super tweeter added. They don't need it as the KEF T27 tweeter is quoted as extending up to 30kHz. Judging by the recessed dome tweeter and woofer mounting, those are early ones which have had late series bass drivers fitted. Later versions had a T27 with the dome fully exposed. I like the Concerto and certainly prefer them to the Ditton 44s which they should comfortably outperform.

DarrenHW

14-04-2015, 06:21

Thanks for the replies fellas.

Very good speakers those although not seen them with the wee plastic it top left.. had a 5” bextrene mid driver . Depends whats been done to them of course

Yes they're Concertos. Not sure why yours have had what looks like a 'ring' horn super tweeter added. They don't need it as the KEF T27 tweeter is quoted as extending up to 30kHz.

On closer inspection this is clearly a modification, it's mounted on the rear of the baffle and I can see where the baffles been over painted.

Judging by the recessed dome tweeter and woofer mounting, those are early ones which have had late series bass drivers fitted. Later versions had a T27 with the dome fully exposed.

Good eye Geoff! I've taken the cloth off the second speaker and this has the original (B139?) which fits perfectly in the recess. I've removed the earlier B139 and it's marked SP1044, the Tweeters are indeed marked T27 :youtheman:.

I like the Concerto and certainly prefer them to the Ditton 44s which they should comfortably outperform.

Fighting talk indeed! I have a week off booked for the first week of June during which I plan on fitting the SEAS 19TFF1 (which I already have) and externalising the cross overs on the 44's, I think I'll rewire and order some new caps for the KEF's too, they've cost me nothing so from what you say worth a ~£20 punt.

Thanks again for your input :thumbsup:.

The Barbarian

14-04-2015, 12:39

Gordon Steadman

14-04-2015, 12:50

The Barbarian is of course, quite right. Very early one and that little extra tweeter looks 'orrid - I would chuck it and seal the hole. I made a pair of these and from memory, they sounded pretty decent although I don't know how they would compare with the Dittons.

Worth fettling I would think.

The Barbarian

14-04-2015, 14:23

They use the same units as the 'Concertos', however they were a good enough speaker but i always got this impression the Midrange was not that fantastic. However sort the crossover out plonk em on stands around a foot tall they should sound pretty good.Sorting the cabinets out should be easy enough as the baffle board is just screwed on..

walpurgis

14-04-2015, 14:43

There not 'Concerto' they are Kef 'Kit 3'

I stand corrected. Andr'e is right. That would explain the rather rough looking cabinets. I was paying attention more to the drivers than the woodwork. They're still the basis for a decent speaker though and well worth sorting.

KEF Kit 3 was the 'homebuild' version of the concerto package and obviously would only be as good as the standard of construction.

Matched bass drivers and later T27 tweeters would look better (but not sound much different).

I believe the Cambridge R40 crossover was supposed to sound better with these drivers and I think Falcon Electronics do suitable ones too.

I still say these will outperform the 44s with some work. ;)

DarrenHW

14-04-2015, 19:34

The Barbarian is of course, quite right.

When isn't he??:)

Very early one and that little extra tweeter looks 'orrid - I would chuck it and seal the hole.

Agreed!!

I made a pair of these and from memory, they sounded pretty decent although I don't know how they would compare with the Dittons.

Worth fettling I would think.

That is the million Dollar question! I've followed a thread on DIYAudio for modding the 44's and a few members who followed the same procedure have moved onto Concerto's and not looked back.

They use the same units as the 'Concertos', however they were a good enough speaker but i always got this impression the Midrange was not that fantastic. However sort the crossover out plonk em on stands around a foot tall they should sound pretty good.Sorting the cabinets out should be easy enough as the baffle board is just screwed on..

I believe the Cambridge R40 crossover was supposed to sound better with these drivers and I think Falcon Electronics do suitable ones too.

Are there any guidelines for servicing / modding the x-overs. I've been reading around and have seen mention of "improving" the x-overs but no further details. Are we talking Alcap, Polyprops or a complete reworking? I'll look up the R40 x-over :thumbsup:

I stand corrected. Andr'e is right. That would explain the rather rough looking cabinets. I was paying attention more to the drivers than the woodwork. They're still the basis for a decent speaker though and well worth sorting.

KEF Kit 3 was the 'homebuild' version of the concerto package and obviously would only be as good as the standard of construction.

I wasn't sure whether these were a kit build (saw some mention of this early this morning) or an attempt at new cabinets. Were the baffles supplied with the kits as the router work is very good if DIY.

Matched bass drivers and later T27 tweeters would look better (but not sound much different).

I have read that the later tweeters were supposed to be better, although I think there is also a modern (Morel?) replacement. I'm already tempted to buy a matching bass driver, I've read that the earlier bass driver is the one to have?

Thanks again for all the input.

struth

14-04-2015, 19:40

Paul at REFFC could easily do you a nice set of xovers. His work is excellent and very reasonable.

The Barbarian

14-04-2015, 19:46

Not worth it. as mentioned Falcon Acoustics. They do an upgrade 'Concerto' X-Over fora bout £25.00

Yes Darren the boards were already machined. Thats what i was trying to say with them being just screwed in a new cab would be easy cos it's the baffle boards that DIYers have the problem with looking proffesional.

The Barbarian

14-04-2015, 19:51

http://www.falconacoustics.co.uk/crossovers-ls35a-networks-filters-falcon/crossovers-ls35a-networks-filters-falcon/kef-concerto-b139b-b110-t27-crossover-dn12-sp1004-upgrade-network.html

Gordon Steadman

14-04-2015, 20:28

If you could afford it, I would also go for the new T27 that Falcon produce, together with the LS35A metal grilles and felt surrounds. I'm sure that the later T27s are better than the originals. I use the grilles and felt on my KEF101s and it has improved the sound and balance considerably. Many people used to complain about the slight sting in the T27's output - not that it bothered me - but they are really smooth with the grilles on. No guarantee that changes will work of course but definitely worth a go. (They do 'seconds' of the grilles where the finish is not quite 100% - I can't see much wrong with them and it saves a few quid)

The Barbarian

14-04-2015, 21:01

Tell you what why not replace everything while were at it :rfl:

DarrenHW

15-04-2015, 05:51

Yes Darren the boards were already machined. Thats what i was trying to say with them being just screwed in a new cab would be easy cos it's the baffle boards that DIYers have the problem with looking proffesional.

Yes, reading back through I see that now. Sorry, I didn't have much time yesterday was in a rush to reply to everyone who'd taken the time to comment.

Not worth it. as mentioned Falcon Acoustics. They do an upgrade 'Concerto' X-Over fora bout £25.00

Thanks for the link, I see the do a couple of options I'll check them out when I get home this evening, they do seem like a good value option.

If you could afford it, I would also go for the new T27 that Falcon produce, together with the LS35A metal grilles and felt surrounds. I'm sure that the later T27s are better than the originals. I use the grilles and felt on my KEF101s and it has improved the sound and balance considerably. Many people used to complain about the slight sting in the T27's output - not that it bothered me - but they are really smooth with the grilles on. No guarantee that changes will work of course but definitely worth a go. (They do 'seconds' of the grilles where the finish is not quite 100% - I can't see much wrong with them and it saves a few quid)

I've read other recommendations to swap the tweeters, this will be something I'll look into if they're keepers. Grille and surrounds is also something that I've thought about (I don't have them) the grilles make a significant difference to the 44's and I prefer them on for the reasons you menion. Does anyone know how the "original" grilles were constructed i.e. are they a frame or a board with cut outs for the drivers?

DarrenHW

17-04-2015, 16:49

I'm looking at the options for x-overs and as if there aren't enough options to bake my noodle (5, 5aB, 5c :scratch:) the x-overs I have, have 60MFD not 30MFD in the Mid:

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5093_zpsefkued4m.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5093_zpsefkued4m.jpg.html)

Both mids are marked SP1003, one reads 7.8 one 7.9 ohm, can anyone tell me what's going on?

walpurgis

17-04-2015, 17:04

There was nothing wrong with the way the Concerto sounded in original trim. I'd be inclined to keep them as near standard as possible with late series drivers fitted if possible. Empty Concerto cabinets crop up on eBay that have been scavenged for drive units. Might be worth keeping an eye out for a tidy set. Going for late series drive units need not work out too expensive, as you can definitely get money back on the old ones. A good, original pair of Concertos is a real seventies classic, which is as yet not really appreciated and I predict they'll become sought after and highly collectable pretty soon.

The Barbarian

17-04-2015, 17:26

DarrenHW

17-04-2015, 17:40

They were a good speaker but it's the midrange i had trouble with..Darren why not sit down & listern to them in the original state see what you think.. However why mess about when those Falcon boards are on £25! besides the new Inductors look better to me.

That's what I want to do it's just the Falcon boards use 30MFD (as does just about every other schematic I've seen) and I have 60MFD in the existing x-over.

14516

I'm not truing to reinvent the wheel just want to give them a fair day in court v's the 44's. As everything was quite hacked up I'm currently rewiring them with Van Damme Blue (same as the 44's) and banging in some new posts. New caps and they're good to go, I would have just ordered like for like replacements but then you pointed me in the direction of the Falcon boards now I'm not sure if I should swap the 60's for 30's and if there's also an implication with the inductors?

If that sounds a bit passive aggressive it's not intended that way, I'm glad you pointed me in the direction of the Falcon boards and appreciate the help :).

The Barbarian

17-04-2015, 17:48

No worries Darren just trying to save you some cutter & farting about time. If i were to choose between the '44' & the 'Concerto' Kit 3 id opt for the latter..

:eyebrows:

ps: another thing i would personally do is get rid of the external mounting way they fitted the X-Over PCB.

Gordon Steadman

17-04-2015, 18:20

Grille and surrounds is also something that I've thought about (I don't have them) the grilles make a significant difference to the 44's and I prefer them on for the reasons you menion. Does anyone know how the "original" grilles were constructed i.e. are they a frame or a board with cut outs for the drivers?

The grilles I was talking about are these.... not the outside covers, in case that is what you thought I meant.
http://www.falconacoustics.co.uk/ls3-5a/falcon-ls3-5a-b110-drive-units/ls35a-tweeter-grilles-t27.html

DarrenHW

17-04-2015, 18:53

No worries Darren just trying to say you cutter & farting about time.

I realise that and appreciate it, I'll email Falcon for an appropriate replacement.

If i were to choose between the '44' & the 'Concerto' Kit 3 id opt for the latter..

:eyebrows:

I'm surprised it's taken you this long to say it :D

ps: another thing i would personally do is get rid of the external mounting way they fitted the X-Over PCB.

I've just finished rewiring one of the cabinets to the external mounting :doh: I know what you're saying though and would want to address this if they're keepers.

The grilles I was talking about are these.... not the outside covers, in case that is what you thought I meant.
http://www.falconacoustics.co.uk/ls3-5a/falcon-ls3-5a-b110-drive-units/ls35a-tweeter-grilles-t27.html

Thanks Gordon, I knew what you meant I have them on the HF2000's in the 44's. You also referenced the LS3/5a which took a day to percolate (I knew I recognised the letters and numbers from somewhere :scratch:) before I realised what you were referring too, it's got me quite excited about getting these up and running and all the other possible designs that utilise the drivers. I imagine IMF TLS 80's would be right up your boulevard?

walpurgis

17-04-2015, 19:01

DarrenHW

18-04-2015, 06:49

I'd experiment with the internal cabinet damping material. The Concerto can sound a little underdamped depending on surroundings. Get it right and you'll get some pretty solid, tuneful bass that goes plenty deep enough.

I'm trying to curb my enthusiasm for these speakers until I've actually listened to them properly. However, "if" they're going to replace the 44's the T27/B110/B139 combination is just about perfect for me as my system is both HiFi and Home Cinema. The plethora of cabinet designs for these drivers would allow me to use the same drivers for front, rear and centre speakers in cabinets suitable for their location.

Right now (and letting my imagination run wild as usual) I think I'd like to implement a Transmission Line cabinet for the fronts which double as stereo speakers, a LS3/5a type cabinet and the B139 used as subs for the rears, and as for centre, well who know's the worlds my oyster here I could accommodate just about any cabinet design.

Maybe over ambitious considering my severe lack of technical knowledge and definitely premature but I'm struggling to contain my excitement for these speakers and the flexibility they offer. However this driver combination is so well supported buying cross over components shouldn't be an issue, cabinet designs are available and I have the tooling, space and ability (apart from never applying veneer) to build the cabinets.

I've sent an email to Falcon regarding the cross overs and hope to have these ready to fit by the end of next week so should have everything burnt in and ready to do battle with the 44's by the May bank holiday weekend :carrot:.

DarrenHW

27-04-2015, 12:56

Disappointingly I received no response from Falcon regarding their x-overs and their recommendation for mid range caps so I ordered like for like caps and a pair of 30MFD as usually found on these x-overs. For some reason I've been sent 7.5MFD not the 7MFD caps I ordered, I'm not going to waste my time asking why as I'm sure I'll only be told they've sent those closest to the 5% 7MFD on order. All in all I'm quite disappointed by Falcon and their overblown p+p charge adds further insult.

Moving on... I recapped the x-overs as "original" with 60MFD in the Mid,

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5130_zps9jr4rhfl.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5130_zps9jr4rhfl.jpg.html)

it didn't take many minutes of listening to realise the Mid was far too recessed so I swapped this for 30MFD which was an immediate improvement to driver integration.

I've added some new binding posts to make swapping speakers easier and rewired with 2.5mm Van Damme Blue.

The replacement B139 was too small for the cutout for the original B139 so I cut a filler piece from some 6mm PLY and applied a bead of gutter sealant (doesn't set) to the baffle. I know this is far from ideal but I thought better than an air gap around the driver.

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5133_zpsg1shqzlr.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5133_zpsg1shqzlr.jpg.html)

I cleaned up the drivers with some de-ionised water, applied some rubber reviver and rotated them 180 degrees before re installing. I currently have them burning in hooked up to a receiver I can leave on, I thought this would be the best method for burn in as it should loosen up the drivers at the same time.

It's too early to make any judgement on the speakers but in comparison to the 44's I would say they do seem to let more detail through and have better depth and separation. Like I say, early days yet but I'm looking forward to comparing them to the 44's.

Gordon Steadman

27-04-2015, 14:27

I think Falcon's problem is communication. When I ordered the grilles and felts for my T27s, they sent the wrong felts. I then spent ten days sending emails to ask what was going on. The correct replacements arrived before I got an "oh sorry, didn't we tell you we had sent replacements"

The actual service was pretty good allowing for the mistake - which can happen to the best.

DarrenHW

11-05-2015, 06:51

I've been listening to these for the last week now and they're really growing on me. In comparison to the Ditton 44's, the sound stage from the KEF's is far larger, however the bass from the 44's has more slam but the KEF's possibly go deeper, the KEF's produce more detail but the Celestions are more aggressive, the KEF's have a more natural mid but the 44's don't have a lisp :doh:

This is how my last week has gone, switching between the KEF's and the 44's both have different strengths and weaknesses. I find the 44's more exciting but the KEF's more natural and detailed, if only I could keep the bass from the 44's with the tweeter and mid from the KEF's.

What I'd like to do now is build a separate cabinet for the Mid/Tweeter for the KEF's. I'm thinking about a LS3/5a cabinet but keeping x-over values as they are for now, is this a good or bad idea, any recommendations for this?

tubehunter

11-05-2015, 08:26

walpurgis

11-05-2015, 08:54

Not a great idea. If you want to go the LS3/5a route get proper crossovers from somebody like Falcon and then use a sub if needed. You could actually use a sub crossover with the 44s or house the 44 or KEF bass units in separate boxes.

DarrenHW

11-05-2015, 10:00

http://www.ebay.co.uk/itm/KEF-105-Reference-speakers-/161693212232?pt=LH_DefaultDomain_3&hash=item25a5aa9e48
:)

They're still on my hit list since hearing yours Duncan, just an expensive option for 3 pairs for Home Cinema! Wouldn't mind your input on this (http://theartofsound.net/forum/showthread.php?34047-Quad-405-servicing-modding-advice&p=647584#post647584) if you have a minute?

Not a great idea. If you want to go the LS3/5a route get proper crossovers from somebody like Falcon and then use a sub if needed. You could actually use a sub crossover with the 44s or house the 44 or KEF bass units in separate boxes.

Sorry Geoff, I should have been clearer. No, at this stage my intention is not to go the LS3/5a route but as you suggest the Bass (B139) left in the existing cabinets with the Mid (B110) and Tweeter (T27) housed in another cabinet. X-over remaining as is with longer wires for mid/tweeter cabinet, if this is successful I'd then like to experiment with some of the B139 cabinet designs.

The only reason I cited the LS3/5a is because there are plans available to make the cabinets but I don't know whether this is a good idea with stock x-over values, if not is there another B110 / T27 cabinet that you could recommend?

Crossing over to the 44's is also something that has crossed my mind :eyebrows:.

walpurgis

11-05-2015, 10:09

I see what you are thinking. If you're staying with stock crossover values then personally, I'd be inclined to give the B110 a cabinet a bit larger than the LS3/5a in order to keep colouration down. The B139 can be housed in any number of different cabinets. IMF and Cambridge used it very successfully in big transmission lines.

You may find something like KEF Coda boxes on eBay. people are stripping them for drivers.

DarrenHW

11-05-2015, 11:12

I had originally planned on a TL cabinet but the 2 box design would be preferable for rear speaker placement. Thanks for the Coda recommendation, I have read (somewhere :scratch:) about an increased volume being an improvement for the B110.

DarrenHW

12-05-2015, 07:50

Any thoughts on building CS1A cabinets (using existing DN12 x-over)?

It has a slightly larger volume than the Coda 7.26l - 8l, although I may slightly increase this (deeper) following these guidelines http://www.hifiloudspeakers.info/Anatomy/SpeakerSystems/LS3_5a/LS3_5aJohnSmith.html.

struth

12-05-2015, 10:05

my imf s use a kef 200 driver. sounds v nice

spendorman

12-05-2015, 10:14

Is that the DN12 from Concerto?

My thoughts are that you need to use the CS1a crossovers with B110 SP1003 and T27 SP1032.

Any thoughts on building CS1A cabinets (using existing DN12 x-over)?

It has a slightly larger volume than the Coda 7.26l - 8l, although I may slightly increase this (deeper) following these guidelines http://www.hifiloudspeakers.info/Anatomy/SpeakerSystems/LS3_5a/LS3_5aJohnSmith.html.

DarrenHW

12-05-2015, 10:18

my imf s use a kef 200 driver. sounds v nice

Nice, the Super Compacts in your sig I presume? I like the look of the IMF TLS80 but only found out about these after passing on a pair of Ditton 15's for £20, I'd have had all the drivers needed :(.

struth

12-05-2015, 10:25

Nice, the Super Compacts in your sig I presume? I like the look of the IMF TLS80 but only found out about these after passing on a pair of Ditton 15's for £20, I'd have had all the drivers needed :(.

yep super compacts...very nice speak that are now out of use. used to be on my yaqin valve amp and have tried them on the main system b4 i got the wad. lovely condition too....must try them with the el84 and see how well they do with the delicacy of 16 watts. got some pics somewhere and should be some in my gallery page..glw your conversion...i am following it

DarrenHW

12-05-2015, 10:33

Is that the DN12 from Concerto?

My thoughts are that you need to use the CS1a crossovers with B110 SP1003 and T27 SP1032.

Hi Alex, Yes it is the DN 12. I agree with what you're saying, however my first priority is to build the cabinets for mid/hf, then play around with lf cabinets to establish the final configuration. I believe I could adjust the Cantata (although it uses T52 not T27) or CS7 (again T33 not T27) x-overs and I'm also thinking about building a lf cabinet with Peerless 830669 as a 105.2 copy (T52 not T27).

I don't know anything about x-overs so I'm trying to keep it simple for now and address the x-overs once the cabinets are built, do you think that's feasible?

spendorman

12-05-2015, 10:36

Is that the DN12 from Concerto?

My thoughts are that you need to use the CS1a crossovers with B110 SP1003 and T27 SP1032.

Here CS1a crossovers and spec, crossovers assembled by me many years ago.

spendorman

12-05-2015, 10:45

Here CS1a crossovers and spec, crossovers assembled by me many years ago.

Sorry, photo of crossover is CS1a, but the spec sheet is for CS1, I have the CS1a sheet somewhere.

DarrenHW

12-05-2015, 11:18

No problem Alex, I have it thanks. What did you think to the CS1A's / did you try any other B110 / T27 combo?

spendorman

12-05-2015, 11:32

No problem Alex, I have it thanks. What did you think to the CS1A's / did you try any other B110 / T27 combo?

I found the CS1a spec sheet, but the PDF was too big to upload.

I built the CS1a's many years ago, pretty good, then I got Chartwell 15 Ohm LS3/5a's, not that much difference really, Chartwells may have had very slightly better mid, but it's marginal. I stupidly sold the CS1a crossovers. Put in Coda crossovers, not that good. I bought off ebay what was advertised a CS1a crossovers, but I reckon there are Ref 101 design crossovers, but the components are much better than in the 101. They are also like CS1 design. Not really correct for the SP1003, but in practice they work well. The only B110's that I have are the SP1003.

I also have JR149, bass is better than the LS3/5a, but mid not quite as good in my view.

spendorman

12-05-2015, 11:57

Hi Alex, Yes it is the DN 12. I agree with what you're saying, however my first priority is to build the cabinets for mid/hf, then play around with lf cabinets to establish the final configuration. I believe I could adjust the Cantata (although it uses T52 not T27) or CS7 (again T33 not T27) x-overs and I'm also thinking about building a lf cabinet with Peerless 830669 as a 105.2 copy (T52 not T27).

I don't know anything about x-overs so I'm trying to keep it simple for now and address the x-overs once the cabinets are built, do you think that's feasible?

Sorry again, I now see now what you are thinking.

I stood my LS3/5a's on top of KEF Concertos, and it really showed how bad the DN12 crossover is. In all but the deep bass the LS3/5a was far far better, midrange on the Concerto is quacky, coloured, muddled and the treble is a bit spitty. I fiddled around with the Concerto's, could not improve them much without drastic mods, broke them up.

A friend incorporated LS3/5a crossovers into the Concerto, and this worked very well. Not sure of the exact details here.

I gave another friend a second pair of Concerto's, his thought on the sound was the same as mine, he modded them by removing the B110 and fitting the dome mid from Celestion Ditton 66, crossover was modded too. This produced a very good speaker.

To get a good result from KEF B139+B110+T27 is not really possible keeping it simple.

DarrenHW

12-05-2015, 12:42

spendorman

12-05-2015, 12:47

Thanks for you input Alex :thumbsup:.

I know what you're saying about the mid and treble in the concerto's, I had hoped this could be improved with a more mid focused cabinet but from what you say it would seem the x-over is more the issue, but that's encouraging in it's own way :).

Really, its mainly the B110, it needs a lot to make it sound good, after all, look what the BBC had to do to it in the LS3/5a.

DarrenHW

24-05-2015, 08:16

After living with the KEF's exclusively for the last 2 weeks I plugged the 44's in again this weekend and my decission is made, the 44's are staying! I love the way the KEF's image, whether this is room interaction or where the KEF's excel I don't know but they create a "wall of sound" that I really like. They have a smoother sound than the 44's which is very (for want of a better word) relaxing, but this is one of the issues I have with them, they lack the excitement of the 44's. The 44's throw the music at you and hit you in the chest with bass, I find this far more enjoyable, my lounge system is all about excitement, not relaxation. I mentioned earlier that the KEF's are more detailed than the 44's and I still think they are but IMHO they're a little too HiFi and I miss the raw energy of the 44's. The 44's seem to be a better match with the Quad 405's (which may offer further explanation of my preference for the 44's), with the volume dial at 12 o'clock the 44's shake my chair and fill the room, the KEF's are at more like 2 o'clock but they still won't shake my chair :(.

I may use the KEF's in a 2 box arrangement in the kitchen, I'm certainly going to hang on to them for a while but they have galvanised my decision to use 44's in the lounge.

Thanks for everyone's help and input :).

karma67

25-05-2015, 18:57

Sorry again, I now see now what you are thinking.

I stood my LS3/5a's on top of KEF Concertos, and it really showed how bad the DN12 crossover is. In all but the deep bass the LS3/5a was far far better, midrange on the Concerto is quacky, coloured, muddled and the treble is a bit spitty. I fiddled around with the Concerto's, could not improve them much without drastic mods, broke them up.

A friend incorporated LS3/5a crossovers into the Concerto, and this worked very well. Not sure of the exact details here.

I gave another friend a second pair of Concerto's, his thought on the sound was the same as mine, he modded them by removing the B110 and fitting the dome mid from Celestion Ditton 66, crossover was modded too. This produced a very good speaker.

To get a good result from KEF B139+B110+T27 is not really possible keeping it simple.

i believe these sort them out.

http://www.wilmslow-audio.co.uk/concerto-upgrade-crossovers-480-p.asp

spendorman

25-05-2015, 19:53

i believe these sort them out.

http://www.wilmslow-audio.co.uk/concerto-upgrade-crossovers-480-p.asp

Not in my view, I bought a pair of those too.

karma67

25-05-2015, 19:59

well what do i know then? :)

spendorman

25-05-2015, 20:16

well what do i know then? :)

Well, it's was a logical thought.

I use those crossovers, modified, in some homemade speakers containing an EMI 14"x9" bass unit, Audax Bextrene 5" midrange, Celestion HF1300 and Coles 4001G. Much better than KEF Concerto.

Martyn Miles

13-06-2015, 19:11

I found the CS1a spec sheet, but the PDF was too big to upload.

I built the CS1a's many years ago, pretty good, then I got Chartwell 15 Ohm LS3/5a's, not that much difference really, Chartwells may have had very slightly better mid, but it's marginal. I stupidly sold the CS1a crossovers. Put in Coda crossovers, not that good. I bought off ebay what was advertised a CS1a crossovers, but I reckon there are Ref 101 design crossovers, but the components are much better than in the 101. They are also like CS1 design. Not really correct for the SP1003, but in practice they work well. The only B110's that I have are the SP1003.

I also have JR149, bass is better than the LS3/5a, but mid not quite as good in my view.

I have all the components for two CS1a crossovers and the boards to build them on if anyone is interested .
Also, two Falcon Acoustics LS3/5a cabinets and accessories plus two T27s.
I've bought a Falcon LS3/5a complete kit and these components are now surplus to requirements so I've decided to sell these parts.
M Miles.