[Elecraft] KX3 speaker: distortion from mechanical vibration?

[Andrew Moore]

Don, Ron, Wayne & all--

Looks like the buzzy speaker distortion problem was in fact due to the gaps
between the top and bottom halves of the enclosure. This may be premature
as I haven't made a permanent fix but all signs point to these gaps.

Ron, I was wrong in assuming that Don was referring to the gap I
illustrated - I hadn't seen or considered the one directly below the
speaker grille - however, the one I illustrated may in fact be part of the
problem as well.

It seems like we're dealing with two types of distortion: 1) AGC threshold
too high and 2) mechanical vibration of the KX3's enclosure.  The first
seems to be solved by going into the menu and setting: a) AGC MD to "ON",
b) AGC SPD to "FAST" and c) AGC THR(eshold) to "005" (the default used to
be "007" but Wayne says that should now be "005" as shipped from the
factory).

The second seems to be solved by focusing on three main gaps between the
upper and lower enclosure halves. Looking at the KX3 with the speaker
facing you, one gap is about 4 inches long and is located to the left of
the speaker; one is about 1.5 inches long and is directly under the speaker
grille; and one is about 1.5 inches long and is located to the right of the
speaker.

The solution appears to be either making sure the gap is wide enough so the
two halves of the enclosure don't contact each other, or actually closing
this gap by inserting some kind of material that dampens the vibration. In
my case, I'm going for the latter, and will attempt to use an
adhesive-backed felt. I think this would be easier than filing, prying,
bending, etc., and will work with minimal fiddling if the enclosure is ever
opened up again.

Images illustrating the gaps (two of them courtesy Don W3FPR) follow via
links below.

Thanks Wayne/Don/Ron/all for helping debug this. Even with my temporary fix
(fabric stuffed into the gap), the problem is about 90% solved.

This is a very capable little speaker.

Disclaimer... all off the above is to the best of my knowledge and is my
own experience with one KX3 sample.  I don't speak for Elecraft and this is
not necessarily an official solution, nor am I saying this was even a
"problem" to begin with. I'm just trying to make my KX3 behave the way I
want. Fantastic little rig!

--Andrew, NV1B

Links:
http://i47.tinypic.com/21l5vn9.jpg
http://i47.tinypic.com/34pkpvs.jpg
http://i48.tinypic.com/108a5pi.jpg