Linkwitz Hope


2007-12-19 9:56 pm
Peace to all !!

Yes, I'm another builder wanting to copy Mr. Linkwitz Pluto design.
This is my first major speaker build.

I've always wanted to build a Linkwitz design since I saw
his Phoenix, but it was very expensive and complicated for me.

Now I have seen people like Gainphile, Davey, rich31td, and many
others build this basic design with a miniDSP board.

So I hope to converse and gain help from some of you who
have built this design.

My stumbling blocks are...

Building an encasing square box around the PVC tube.
(i know it would be easier to just leave the tube alone,
but I really like what others have done with the concept)
The diagonal really gets out of hand when trying to encase
a tube with mdf. Diffraction by the numbers indicate a
frequency of around 650hz or so for 6 - 7 inch diameter,
but I've read since its radiating at 90 degrees so it may
not be a huge problem.
(Yes, i've been reading your posts, sirs )

Another about the case, would be vibrations exciting
the casing panels from the bass frequencies.
I could isolate the casing with firm foam at the top
and bottom and stuff the remaining voids with fill.
The tube of course, per Mr. Linkwitz does not radiate
very much vibration so the panels, not exposed to pressure
from the drivers, would not re-radiate, but the actual
output from the bass driver into free air might excite
the panels by air coupling. I don't know...

Of course I've read posts discussing the miniDSP programming
but it hurts my head to a degree.
Davey reports using simple LR crossovers, but some get
into bi-quad programming, so I don't know if I need bi-quad
or not.

I am only trying to get 80% of the sound quality of Mr. Linkwitz's
design, since the cost of the ASP and such is beyond my means.
Mr. Linkwitz is very meticulous and has resources such as a vast
experience in listening to great designs and education far
beyond me. So I copy.

Any discussion or help would be greatly appreciated !!!