KEF Q150 breeding

I have been thinking about diying something based on KEF coaxials for a long time... Now I noticed this discount offer and orderd two pairs.

Q150 is the cheapest coax that KEF makes, and the driver mostly lacks bass performance and power capacity. Xo circuit must be very simple. It was tested with Klippel NFS by Erin

Response is pretty good! Obviously there is great potential for dsp-xo and 3-way system!


Göran ("gornir" at diyaudio) has measured the R series coaxial

Here Q100 with same 5,25" tested by Amir
and Q350 with 6,5"
Last edited:
  • Like
Reactions: 1 user
Q150 is the cheapest coax that KEF makes ... Xo circuit must be very simple.

The crossover circuit for the Q100 that you also mention is certainly very simple.

It consists of a 0.68 mH inductor in series with the mid/woofer section and a 3.9 uF capacitor and 0.68 ohm resistor in series with the treble section.

However, I think you were the one to have told me that! :D
Last edited:
Well well - dipole bass is something I've never tried! I have a pair of 8" woofers lying around now... shallow U-frame proto?

I just ordred a new UMIK-1 v2 to replace my dead v1. The v2 has USB-C port

Link to my previous coaxial project, with SEAS MR18, closed box woofer

Pic of MR183 and MR18 in a factory-made box that I still have a pair of.

View attachment 1205924 View attachment 1205925

Funny. My v1 died too.
^Perhaps they have a software "bug" that tells to stop working after 10 years...

I have a MiniDSP 2x4HD that I use for driver and speaker prototyping. And two units used in my AINOgradients.

Today I updated minidsp 2x4HD firmware and loaded Device Control software. I have three units and I had to uninstall SW when I switched the unit. Installation SW told that I have other instances running even after I restarted the PC, before uninstalling. I didn't have time to test after this if all units re-connect immediately after update, hopefully yes.

After update I instantly noticed the effect in sound of my AINOgradients' PRAT, presense, imaging, attack, spaciousness and brilliance - there was no difference! :)
Last edited:
Seriously, why do SO many companies cheap out on the crossover filter SO badly?
Are they that desperate to turn and safe every penny? (that is a rhetorical question)

I am not only talking about the quality of the components, but even how the crossover is designed.

There are so many speakers that can sound just totally fine, to even incredible by just remeasuring and redesigning the crossovers. I have also done that quite a bit in the past.
  • Like
Reactions: 4 users
Also something I really don't understand.

I measured 2x12"/1" PA speakers and we detected that the 12"s run completely without crossover. These where hanging in a football stadion for >10 years - that's not cheap stuff. They always had problems with speech off axis vertical ... oh really?
The 1" they used is a pretty good one and could have taken a lower crossover point with ease. They just didn't care to add 2-4 more components to the crossover ...
  • Like
Reactions: 1 user
Perhaps lack of listening skill, perhaps pressure with schedule or something. Perhaps need to reduce "quality" to justify some more expensive model and drive customers buy that.
I have seen and worked with quite a few companies over the last 15 years or so.

After all that experience you would be surprised that despite the reputation of some companies, how many actually still only look at one single axis measurements. Even with all the equipment and tools they have.

Or how many just only work from the idea of, "well this is what we have done all those years. Never change a winning team" (seriously, that saying makes my blood boil these days hahaha).

Or how some of them seem to be totally stuck in time. When you show them something obvious like how simple DSP's or how gated measurements work. It's like seeing some miracle for them.

Although more often than not, they just brush it off like it's unnecessary and excessive........ Go figure.

I also know companies that actually do know what they are doing. They have a healthy good quality product line-up, without compromising to desperately. Sometimes some minor unusual things according to taste, but that's all fine.
  • Like
Reactions: 1 user
A big manufacturer like KEF "must" make different series of speakers to sound different. Like tmuikku wrote, the customer who perhaps listens to speakers at retailer, must be able to hear the difference in sound, to convince herself that more expensive is much better! Low price means worse cabinet and simple xo design (time spent in development). In case of KEF also the driver is different despite it looks same as LS50.

Q150 replaced Q100, BR port is now on the backside and CEA response is much better.
Low price means worse cabinet and simple xo design (time spent in development).
Having done and still doing this work myself. (paid as a professional)
We are talking pennies as well as maybe a couple of hours extra AT MOST.
We are not talking about refining every detail, but just to make it just nice and acceptable.
You won't see this back as additional costs.

I think it's just bad design philosophy.

Like I said, there are plenty of other companies able to get the most out of every design. No matter the price tag.
It's also not hard to scale products accordingly.
Last edited:
  • Like
Reactions: 2 users