The sound from either of
these styles will be almost
inaudible until the shell is in
place, as the shell is the baffle
that directs the sound out the
rear truck opening.
If you want to test this loco
before you install the shell, just
wrap your finger around the
end of the weight. The sound
should come up significantly.
It won’t achieve the ultimate
timbre or volume until the
shell is installed.
Over the truck
with a baffle
Similar to the Atlas ver-
sion [5] and [6] is a method
that works on a lot of locos.
I fit the speaker over the
rear truck of the Kato SD45,
shown in [7]. Once I had a
good dry fit, I used styrene
to build a baffle to keep the
sound coming off the front of
the speaker directed down-
ward to the truck opening.
This was done because the
weight is not a close fit, like
the Atlas version. I’ve tried
this style of installation with
and without the bits of plastic baffle. I find the baffle helps.
Only takes a few minutes, so why not?
The speaker is held down with caulk. Remember to keep
caulk away from the cone. I glue the styrene to the sides of
the speaker with solvent (MEK or a commercial product). A
future column will cover some methods to make quick work
of this fabrication.
Using the shell as part of an enclosure
Folks who have followed my columns know that I prefer to baffle
the sound, rather than to enclose the speaker. However, there
are times that an enclosure is about the only possible game. The
pre‐designed enclosure [2] discussed previously is one case.
Another kind of installation is where there is no place to put
the speaker except to build an enclosure using the bottom of
DCC - 7
