Greg Timbers Interview

[Ian Mackenzie]

I have a follow up on Greg’s system below for you guys. Greg now spends most of his time on his house boat enjoying his retirement. So snippets about his system are few and far between.

Hi Ian,

“For your amusement, I have attached pictures of my system below. I have 2 15”s and a 4” compression driver per channel. My Sub is a DCD 18” mounted in my fireplace (blocked off). Everything is sealed, neither 15 is rolled off on the low end. The 18, and both 15’s all extent from the room cutoff at 13 Hz up to their respective roll of points of 80 Hz, 150 Hz and 750 Hz. The system uses linear phase crossovers and has no group delay. The Impulse response shows the alignment. The only reason there is a lift before the main spike is that the Sub has a much wider impulse: and that is what you see preceding the main spike.”

The thing is Greg’s system is a constant work in progress. On each occasion l’ve heard it the system has become progressively more complex.

I don’t know the reason for the new enclosures or details of the horn. It was made in Greg’s impressive workshop using a 3D printer. Last l heard Greg was Beta Testing the latest DEQX software which Greg said was a big improvement. No idea where DEQX is with that.

If l can glean any more on Greg’s system l will.

Ian

PS. I would be surprised if there isn’t a neat active solution for the 4367. I have asked the question.

[grumpy]

Thanks Ian,

Always nice to see what's cooking in the kitchen

[Ian Mackenzie]

Greg suggested the following for the 4367.

I’ve relayed it to the 4367 owner in Italy with some pointers on obtaining the woofer voltage drive using a Focusrite Scarlet USB interface. It’s up to him now.

https://www.audioheritage.org/vbulle...l=1#post384175

On paper the schematic above is a 3rd order low pass filter but the tech sheet voltage drive is closer 4th order LR -6 db 550 hertz and -24 db 1100 hertz. Measurements at the driver terminals are the most accurate way of measuring the voltage drive. That’s my educated guess.


From GT:

Ian,

I did not spend any time active on the 4367. However, his suggestion of direct driving the woofer and using the passive HF network is good. He could also drive both drivers directly with the crown. I would suggest a 10 db resistor pad on the HF. It will be too noisy to drive directly and a bit dangerous. Should be pretty easy to do.
Sent from my iPad.

[turnitdown]

https://www.youtube.com/watch?v=zDc25x0Zo_o

[BMWCCA]

https://www.youtube.com/watch?v=zDc25x0Zo_o

Thanks.
They need to chip in and buy Greg a better computer/camera!

[Robh3606]

Thanks.
They need to chip in and buy Greg a better computer/camera!

And the drop outs!

Rob

[turnitdown]

I found many interesting points in the second one, including, but not limited to - the synergy of tubes and CDs, invest in a great woofer, his preference for wider dispersion. There was more...and yes, the dropouts were a bit annoying. His endorsement of DSP (to a degree) may nudge me toward a Mini DSP.