KEF - Jack O'Clee-Brown Interviewed

[Deleted member 14468]

Hello,

Knowing this site trends heavily toward engineering-based hi-fi designs, I don't think there's any better person to bring to the forefront than KEF's Dr. Jack Oclee-Brown. As he says in this long interview I conducted with him last month, you can engineer a loudspeaker. Enjoy!

Doug Schneider
SoundStage!

 

[thewas]

You can see how advanced KEF is, the interview is one month from the future (May 2020)!

Now seriously, Dr. Jack Oclee-Brown is a really brilliant engineer who remained humble and gentleman, I had the luck to meet him in person 2 years ago at KEF.

 

[Deleted member 14468]

Ahead of our time! Actually, the slated launched for this interview was May 1, but with people at home right now, we figured it would be best to release it early.

And you're correct about Dr. Jack.

Doug Schneider
SoundStage!

 

[Matias]

Huge respect for him and KEF. I watch/read all his interviews.

 

[Matias]

@jackocleebrown any chance of sending a Reference 1 for Amir to measure? Even though we already have NRC's measurements from SoundStage!, still that would be great.

 

[Deleted member 14468]

We measured it a few years ago:

https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153

Doug
SoundStage!

 

[Jukebox]

@jackocleebrown any chance of sending a Reference 1 for Amir to measure? Even though we already have NRC's measurements from SoundStage!, still that would be great.

Now that would be one veeery interesting review!

 

[aarons915]

We measured it a few years ago:

https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153

Doug
SoundStage!

Yes and the measurements look great, do you guys happen to take all the necessary measurements to create a CTA-2034 style graph or are the measurements posted everything you take? If you guys do have all of the data, it would be very useful to create the Spins from them.

 

[thewas]

Here are more detailed measurements of the KEF Reference 1 from Prof. Goertz who also does the S&R magazine monitor measurements.
https://www.fidelity-online.de/kef-reference-1-messungen/

 

[Head_Unit]

Dr. Jack.

Any chance of a followup? I'd be very curious to ask
- We know the pros of Uni-Q are the concentric sound source, and presumably pattern control. What are the cons? And how does KEF mitigate those? Especially in 2-way designs with no other woofers, for instance, the woofer which loads the tweeter is changing its position; how does that affect the tweeter response?

I'd be really curious if @amirm or someone could run a measurement of the tweeter with the woofer cone displaced fully out, center, fully in and see what happens. (The only way offhand I can think to do that would require superimposing DC on the test signal to displace the woofer cone...I'd hope there's a simpler way...I guess you could do it physically if you had a Uni-Q with a damaged woofer you didn't care about...)