Hi,
I've found a pair of Kef 102 Reference speakers for sale but without the Kube. I understand from the user manual that these speakers are designed to work with the Kube which, as a separate item, is not so commonly available. I'm wondering if these speakers, as good as their drivers are recognised to be, are not really worth much at all without the Kube?
Many thanks, Richard
I've found a pair of Kef 102 Reference speakers for sale but without the Kube. I understand from the user manual that these speakers are designed to work with the Kube which, as a separate item, is not so commonly available. I'm wondering if these speakers, as good as their drivers are recognised to be, are not really worth much at all without the Kube?
Many thanks, Richard
102s + Kube is essentially a sub + Sat system, you could probably use any other sub crossed over correctly...???
IIRC the Kube was a little equaliser designed for this speaker. It won't go as deep without it. On the positive side it was just a 2nd order HPF with a hump causing the system to act as a sixth order highpass (4th order is coming from the reflex tuning of the speaker).
The one who desigend it (can't remember his name) is also a member of this forum and he once posted something about it. With the search function you may probaly find it.
The circuit as such isn't complicated - you just have to find the right dimensioning.
Regards
Charles
The one who desigend it (can't remember his name) is also a member of this forum and he once posted something about it. With the search function you may probaly find it.
The circuit as such isn't complicated - you just have to find the right dimensioning.
Regards
Charles
I worked for KEF during that era. Be aware that some of the KUBEs did a lot more than just bass EQ, giving considerable midrange flattening also. Can't exactly remember which camp the 102 fell into.
Try this website
SpeakerTalk :: View Forum - KEF Speakers from the 1970s
Either search there or contact speakerguru, a long time KEF engineer.
Nothing would stop you from careful equalization on your own with either analog or digital means.
David S.
Try this website
SpeakerTalk :: View Forum - KEF Speakers from the 1970s
Either search there or contact speakerguru, a long time KEF engineer.
Nothing would stop you from careful equalization on your own with either analog or digital means.
David S.
Thanks very much for your replies. Having followed up on the posts as suggested I find again I'm bewildered by the height of expertise available on these forums. Congratulations!
Back on the Kefs a moment, 'speaker dave'. You think I can with careful EQ bring these speakers back, within reason, to how they were meant to sound, albeit without the extended bass. Sounds like a good place to start.
My amp is a Stereo Reciever NAD 7020e rated at 35w into 4ohms. The Kef 102 speakers require an amplifier capable of delivering 50 to 200 watts into 4 ohms. I am a little under powered here, would it be alright or should I be looking for another amp?
Thanks again, Richard
Back on the Kefs a moment, 'speaker dave'. You think I can with careful EQ bring these speakers back, within reason, to how they were meant to sound, albeit without the extended bass. Sounds like a good place to start.
My amp is a Stereo Reciever NAD 7020e rated at 35w into 4ohms. The Kef 102 speakers require an amplifier capable of delivering 50 to 200 watts into 4 ohms. I am a little under powered here, would it be alright or should I be looking for another amp?
Thanks again, Richard
The systems that used the Kube were generally designed for maximum efficiency rather than flat response. The addition of the Kube then flattened the response. By the way, this is not much different than the original Bose 901 and its EQ. So the 102 will rise considerably in the mids (say around 2k) and will be soft in the bass. If you set up and equalizer with the opposite of that curve, that is a good start. You can have the extended bass as well, with some modest EQ at a frequency just below the natural rolloff.
I would still urge you to visit the KEF site. If you can find a graph of the Kube curve you will be that far ahead in creating the right curve, even with a graphic EQ just trying to approximate it. I think speakerguru has even been able to link some people up with missing Kubes, so it doesn't hurt to ask.
Regarding power, give your NAD a try before you discard it. Required power is a funny thing. 5 or 10 watts is usually way more than you need, but some times 300 watts isn't nearly enough. It really depends on how loud you like to listen, how far from the speakers you are, how dead your room is, etc. The benefit of the Kube is that the system efficiency could be maximized rather than thrown away to extend the bass. I don't think you need 50 to 200 watts.
Regards,
David S.
I would still urge you to visit the KEF site. If you can find a graph of the Kube curve you will be that far ahead in creating the right curve, even with a graphic EQ just trying to approximate it. I think speakerguru has even been able to link some people up with missing Kubes, so it doesn't hurt to ask.
Regarding power, give your NAD a try before you discard it. Required power is a funny thing. 5 or 10 watts is usually way more than you need, but some times 300 watts isn't nearly enough. It really depends on how loud you like to listen, how far from the speakers you are, how dead your room is, etc. The benefit of the Kube is that the system efficiency could be maximized rather than thrown away to extend the bass. I don't think you need 50 to 200 watts.
Regards,
David S.
It's interesting that the Kube tended to flatten response. Perhaps at some stage I might be able to find a Kube to try, though now I'd be very curious to hear what can be done with some equalization.
As you suggest I think I'll give my NAD a go. I'm sure I'll be happy with it for now. Most of my listening is done at low volume and fairly close in to the speakers.
I really appreciate your help and if I turn up some good results I'll let you know.
Regards,
Richard
As you suggest I think I'll give my NAD a go. I'm sure I'll be happy with it for now. Most of my listening is done at low volume and fairly close in to the speakers.
I really appreciate your help and if I turn up some good results I'll let you know.
Regards,
Richard
SpeakerDave is correct. I designed most of the KUBE EQ's, and other than the KUBE for the 104.2, most of them applied midrange EQ in addition to bass extension.
This was done so as to maximise the available midrange efficiency of the system that normally gets "thrown away" in the xover.
As Dave says, without the KUBE, not only will the bass response be mis-aligned, but the midrange will sound "forward", being too strong by typically at least 6dB.
You could attempt to compensate this by tone controls or an equaliser, but you are not likely to readily get the correct compensation without measurement tools.
Documentation on all the different KUBEs is sparse. I have attempted to get this myself from time to time but with limited success.
The circuit for the bass correction was certainly not a simple humped 2nd order filter, but was variously at least one "Friend Biquad" topology or a "Double Integrator Loop Biquad", the former very tricky to design without access to the computer program we wrote to help with the design (thanks Ric!).
On a side note, this October is KEF's 50th anniversary! Get ready to wish them happy birthday!
Andrew
This was done so as to maximise the available midrange efficiency of the system that normally gets "thrown away" in the xover.
As Dave says, without the KUBE, not only will the bass response be mis-aligned, but the midrange will sound "forward", being too strong by typically at least 6dB.
You could attempt to compensate this by tone controls or an equaliser, but you are not likely to readily get the correct compensation without measurement tools.
Documentation on all the different KUBEs is sparse. I have attempted to get this myself from time to time but with limited success.
The circuit for the bass correction was certainly not a simple humped 2nd order filter, but was variously at least one "Friend Biquad" topology or a "Double Integrator Loop Biquad", the former very tricky to design without access to the computer program we wrote to help with the design (thanks Ric!).
On a side note, this October is KEF's 50th anniversary! Get ready to wish them happy birthday!
Andrew
Kef Kube for Kef Reference 103|3 Series Speakers
Andrew,
Do you have any idea where I can get a hold of a Kef Kube for a pair of 103|3 Reference speakers ? I've been searching for one for some years.
Thanks so much for your help,
Victor
Andrew,
Do you have any idea where I can get a hold of a Kef Kube for a pair of 103|3 Reference speakers ? I've been searching for one for some years.
Thanks so much for your help,
Victor
KUBE with KEF R107.2 and/or R104.2
I have a Model 200 KUBE that was given to me years ago. Is it suitable for use with KEF R107.2s and/or R104.2s? As I understand it, the KUBE is required for the R107.2s but optional for the R104.2s. Is that correct?
db
I have a Model 200 KUBE that was given to me years ago. Is it suitable for use with KEF R107.2s and/or R104.2s? As I understand it, the KUBE is required for the R107.2s but optional for the R104.2s. Is that correct?
db
Question answered
In reviewing the installation instructions for the 102.2s, 104.2s, and 107.2s I discovered the Model 200 KUBE is for the 102.2s. The 104.2s and 107.2s have KUBEs specifically designed for them, each labeled as such.
db
In reviewing the installation instructions for the 102.2s, 104.2s, and 107.2s I discovered the Model 200 KUBE is for the 102.2s. The 104.2s and 107.2s have KUBEs specifically designed for them, each labeled as such.
db
I have a 103/3 cube spare. Question is my ac adapter says SP2123. Is this compatible with the 102 cube which is SP2113 Xover?
no mention on Kef site of output voltages from supplies but I read they are specific?
no mention on Kef site of output voltages from supplies but I read they are specific?
I have had 105.3s for a couple of years. I just purchased a Kube 200 on eBay. There's a pdf instruction manual for the Kube available online.
The only speaker model specifically mentioned in the Kube instructions is the 105.3. One reason might be that the 105.3s can be bi-amped simply by removing jumpers between the connectors.
The Kube 200 has exceptional support for this, as outlined in the instructions. There are two sets of outputs for the amps, and one has a level control, so you can use two different amps that have different sensitivity or gain.
My wife, who has better hearing than I do, said the difference made by the Kube was a dramatic improvement. My own experience is that it is subtle and is not immediately noticeable on all music. I would say that the Kube tames an upper midrange peak (or possibly it compensates by elevating the bass and treble.
My usual music is classical. I have a lot of organ music that hits the lowest octave. Some notes I've never heard before.
I have a test CD that has bands for frequencies from 20 to 20k Hz. The 20 Hz band is quite impressive. I refoamed these woofers myself and have been concerned about centering. They reproduce the lowest note with rubbing, so I'm happy.
The only speaker model specifically mentioned in the Kube instructions is the 105.3. One reason might be that the 105.3s can be bi-amped simply by removing jumpers between the connectors.
The Kube 200 has exceptional support for this, as outlined in the instructions. There are two sets of outputs for the amps, and one has a level control, so you can use two different amps that have different sensitivity or gain.
My wife, who has better hearing than I do, said the difference made by the Kube was a dramatic improvement. My own experience is that it is subtle and is not immediately noticeable on all music. I would say that the Kube tames an upper midrange peak (or possibly it compensates by elevating the bass and treble.
My usual music is classical. I have a lot of organ music that hits the lowest octave. Some notes I've never heard before.
I have a test CD that has bands for frequencies from 20 to 20k Hz. The 20 Hz band is quite impressive. I refoamed these woofers myself and have been concerned about centering. They reproduce the lowest note with rubbing, so I'm happy.
104/2
Hi AndrewJ,
I have a Kef 104/2 without Kube and love it without. Amp is a Nad 60 watt 2100 monitors tweaked (works better here than a Chord !)
Do I have to found a KUBE for it for better results (the lake of bass is not a problem for me because the mid-bass are fantastic) ? Could you tell me please how recognize a Kube maid for 104/2 (first serie mono wired) or how to maid one (shematics ?)
Hi AndrewJ,
I have a Kef 104/2 without Kube and love it without. Amp is a Nad 60 watt 2100 monitors tweaked (works better here than a Chord !)
Do I have to found a KUBE for it for better results (the lake of bass is not a problem for me because the mid-bass are fantastic) ? Could you tell me please how recognize a Kube maid for 104/2 (first serie mono wired) or how to maid one (shematics ?)
Have you thought about copying the function and using something like a minidsp instead of the Kube?
Jai
Jai
I don't know how is the target curve of the tailor maid Kube for 104/2? Maybe the choose of the curve matter and the designers choose one after some listening ?
For the moment I have no miniDSP but plan something similar...for a DIY project.
For the moment I have no miniDSP but plan something similar...for a DIY project.
I have pdfs of the Kube 200 instructions and of the schematics, including an image of the circuit board. Unfortunately the resolution isn't good enough to burn a board, but someone could replicate it. None of the parts are hard to find.
I don't know the best way to make these available, but I found them with google. There are lots of dead links, but they are available.
I don't know the best way to make these available, but I found them with google. There are lots of dead links, but they are available.
THANK YOU,
I google it to find it... do you know if it the same for the mono wired Kef 104/2 ref ?
I google it to find it... do you know if it the same for the mono wired Kef 104/2 ref ?
I've replicated it recently (having designed the original when I was at KEF) and offered to get some made on the SpeakerTalk forum. However, it is very expensive to get single pcbs made. It would only be a sensible price per board if at least 6 people could get together to share the setup costs.