Kef Kube equalizer

Audio junkies: Can anyone explain the function of the Kef Kube equalizer, and tell me whether there is a viable substitute? I just bought a used pair of Kef Reference 103/4 speakers. I need to repair the dual-woofer surrounds, so I haven't heard them yet. I have read glowing reviews,however, but most recommend using the Kef Kube 200 active equalizer to bring out the bass response (without colouration, I'm told). I have submitted an Audiogon want-ad for a Kube 200, but I'm wondering if there is a substitute in the event I can't find one. Are these things simply graphic equalizers? Also, on the diagrams I've seen, the unit appears to just have RCA jacks. If that is true, can you even use one with a mid/high-end A/V receiver? Thanks. -KlipschKing
If you can't get at the line level signal, via a TAPE loop or a PRE OUT/AMP IN interface I don't see how you could use an equalizer. Unless, of course, you are willing to modify the receiver to provide the connections.

However, I have had very good results replacing the equalizer that comes with Bose 901 speakers with a Behringer DEQ 2496. It does the speaker equalization job better than the Bose-supplied unit, and does room correction as well.
If your av receiver does not have a tape loop, your only option is to place it between the source component and the av receiver.
Thanks guys. My unit is a Pioneer Elite A/V receiver, and it has both a tape monitor in/out, as well as a pre-amp out. Im not sure about a amp in connection; I'll pull my owner's manual. Pardon my ignorance, but how would using the tape in/out work?? I would play the receiver in the tape mon. mode? I really expected to have 5-way binding-post type connections for right and left channel in/out, but looks like I don't understand the process well enough.
Hi everyone

Would an equalizer from another company work in place of KEF K-UBE or KUBE? I was able to acquire a nice pair of KEF 103.3 speakers but the original owner can't find the KUBE EQ that went along with it. I tried listening and the bass sounded thin. Any recommendations on any KUBE replacements would be much appreciated. Any other solutions around this are more than welcome as well and appreciated.

Years ago, JPS Labs made after market eq's for speakers such as yours, that came with oem bass boost eq's called golden flutes. Another dealer (in Denver?)was making similar products for B&W speakers and maybe others, I think they called them Muaghn boxes or something to that effect. Perhaps you could contact KEF or keep your eyes open for used originals or the aftermarket replacements mentioned above. Without them, your speakers are not able to do all that they are capable of.
Get a Behringer DEQ2496 equalizer. It will automatically make your KEF speakers flat, so you won't need to figure out what the original KEF equalizer did.
A room correction device is an excellent idea. Typically the oem bass boost eq's provided bass boost to compensate for the natural roll off of the enclosure type, e.g. infinite baffle 12dB, reflex loaded 24dB. The advantage of using such an eq, is that it allows the manufacturer to use a smaller loud speaker to get the same bass output of a larger loud speaker. Advantages: (i)use less expensive smaller drivers, smaller drivers are more linear and typically have less energy storage,(ii) smaller drivers permit the use of smaller cabinets, smaller cabinets have better marketing potential, use less materials, need less bracing, weight less, cost less to ship and store.All of which reduce costs. Disadvantages, (i) puts more burden on the amplifier, so amplifier power needs to be greater/more robust and that usually means more expense. (ii) depending on how it's inserted in a given system, requires at least 1 and possibly 2 extra sets of interconnects (iii) Many audiophiles object to any extra circuitry in the audio signal, and eq's (rightly or wrongly) are particularly viewed with suspicion, (iv) it's been my experience that there are some limitations to ultimate volume levels compared to larger (usually much larger) speakers that don't use such a device that are capable of the same bass output.
As the bass roll off is based upon what would happen in an anechoic environment, it doesn't correct for the varying bass responses typically experienced by most real world users. The digital room correction devices that are now available and weren't commercially available when most of these speakers were being devised can now boost, not boost, and/or even attenuate for ones actual room. As these speakers were originally built to meet the demands of extra boost, they may be better equipped to to work with these devices than speakers that aren't so designed.
I'm surprised that with the current digital technology available and the increased use of surround sound, where having many large speakers could become problematic, that this concept hasn't found much new life.
Unsound... Bose was one of the first to use the equalizer aproach. The idea was to avoid trying to achieve smooth response below driver resonance, which is almost impossible. Most speaker designers try to push resonance down by driver design and large enclosures. Prof Bose figured out that roll off below resonance, while steep, is inherently very smooth and therefore correctable by electronic equalization. He pushed resonance up to more than 200 Hz.
Eldartford, I suspect that like most things Bose, the EQ Bose used, might have been used a little differently than the way B&W, ICT, KEF, Thiel, etc. were using their EQ's.
Hi Unsound

Thank you for the detailed response and the suggestions. I've reached out to KEF America to see what they say regarding the KUBE and other alternatives for the 103/3s. I'm also looking for older KEF KUBE EQs and those other manufacturers you mention. I think though with my KEF speakers there was a specific KUBE EQ that was made exactly for it. I saw a KEF KUBE for a 102/2 as well as a KEF KUBE 200 but I don't think those will work with my speakers.

I was hoping an older cheaper Hafler EQ I found locally or an SAE Mark 1 XB could do the job but to get optimum sound quality from the 103/3s I think I have to set my sights higher.


Thanks for chiming in as well. I had seen the DEQ2496 used before in other applications but didn't think it would work for my KEF 103/3 speakers. I'll keep an eye out for one used. New it is over $300 and bit over what I had wanted to spend. I read in another thread I may be able to handle the bass issues I'm having my getting a sub and crossing it over where the 103/3s roll off. The thing is that I don't know what the exact roll off point is on the 103/3s.

Well again thank you both and I have some thinking and searching to do. The help is appreciated.
Jedinite24... I have a couple of Bose 901s in my swimming pool room, where they perform far above what audiophiles would expect. I use a Behringer DEQ2496 instead of the Bose equalizer that came with the speakers and I think it sounds much better. The equalization curve (which includes room effects (as well as the speaker characteristics) is really extreme... much more than what your KEFs would need.
I have a pair of KEF 104.2s, four 102.2s, and four 102s. I don't use my KUBEs with any of them. Instead, I use two Velodyne HGS-15s with the 104.2s and 102s (2.1 & 5.1) and an HGS-10 with the stacked 102.2s (2.1). Cross over to the sub at 80 Hz and don't worry about the roll-off frequency. Crossing over at a higher frequency relieves your amp and speakers of LF duty, leaving it to the sub. I think you'll find that your mains sound better without LF duty, more open with a greater sense of air and transparency.

Crossing over to subs at a higher frequency will certainly work. Yes, relieving the lower frequencies from the mains will relieve your main amps and speakers from some stress, but those frequencies were designed to be covered by the mains with the KUBE, and most subs work better when not asked to go too high. You'd be tossing away some of what the KEF's were designed to do, and stretching what the sub was intended to do. Furthermore, despite claims to the contrary, unless your running more than one sub, I think you'll have better upper bass sound coming from your stereo mains than from a single sub.

Thanks for chiming in too. The subwoofer solution that I mention in my post above turns out came from a thread years ago here in the forum that you contributed too. I couldn't post to that thread because it was preserved for archival purproses.

Eldartford and Unsound

Thank you both again. I have a lot to think about. Do I go with the DEQ2496 or do I get subs and not have the KEF 103/3s work to their full potential? That and the extra equipment I would have to bring into my set-up where the 103/3s will be. 2 subs are going to take up space that I'm beginning to run out of. I'm probably going to try the EQ first and then if not MAYBE a larger single sub. I'm hoping it can do the job of 2. This is for my secondary set-up which I do mostly nearfield listening.
Unsound & Klipschking,

The KEF museum claims the 103/4 has useful LF to 50 Hz, so setting the crossover to a sub at 60 Hz might seem prudent, although I doubt 80 Hz is too high for most high quality subs. I've tried both with my 104/2s, and notice little if any difference, so I use 80 Hz in deference to the smaller 102s I use for center and side channels. Unless you're a pipe organ fan as I am, the 104/2s track the fretting of a jazz bass very nicely, but they won't give you that felt more than heard experience when a big pipe is invoked.


I have a question about your theater setup with your Kef 104/2s with a pair of subs. It sounds like you take the L and R signal from your pre/pro to the subs and output the signal after the 80 Hz crossover on the subs to the Kefs...

My question is.. do you tell the processor that you don't have a sub and let the processor mix the lfe signal (.1) back into the LR channels?

Would you gain anything by taking one of your subs and assigning this to the lfe channel while the other sub does the LR stereo sound?

I have the Kube 200 and just added the sub for home theatre but remember hearing the Kefs with a sub as being a magical system back in the day of two channel music.