Use the manufacturer’s design
The installation shown in [1] was fairly straightforward,
because the frame had cast-in places for the speakers.
Sometimes these come with small weights clamped where
the speakers go, sometimes not. Either way it is a matter of
locating the speaker(s) that fit the outline and thickness. Then
install them. Frequently these speakers are comparatively large
(over 30 mm in diameter).
The specific speakers that were available in the proper size at
the time I did this installation were 8 ohms and rated at 0.3
watts. Since they share the applied power, they can handle 0.6
watts together. This is marginal for a 1 watt output decoder,
but acceptable if you keep the volume down. Check out my
January 2014 column
for wiring methods.
Use a re-designed baffle or enclosure
If you are lucky enough to be working on a model that has
a pre‐designed baffle or enclosure available for it, I recom-
mend you try that method first. Look at [2] shows an enclo-
sure designed by SoundTraxx for the Life‐Like Alco PA using
the venerable 28 mm speaker. SoundTraxx has designed these
for many of the Life‐Like cab diesels. The design places the
speaker inside the enclosure and leaves room for the circuit
board mounted on the frame above the truck. Removing the
board allows the speaker to be outside the enclosure, resulting
in a marginal improvement in the sound; as a result of more
enclosed air volume. Use caulk to seal the holes that were
designed to bring the wires into the enclosure.
2. A SoundTraxx enclosure with a 28 mm speaker in a Pro-
to 2000 Alco PA.
2
DCC Impulses Column - 3
MRH-Jul 2014
