June 3, 1998

Soundtraxx Diesel 1st Gen Horn Options

The Soundtraxx Diesel sound, DSD units, now being released are EMD 1st generation. 3 prototypes are available: Wabco issued with "F" units, & 3 chime Leslie or Nathan styles for Geep's. The Leslie was most widespread. Wabco & Leslie sound the best, Leslie most playable.

Soundtraxx (diesel sound installation & speaker options)

In anticipation of Soundtraxx Diesel sound units & their installation in locos and dummies the most significant aspect is that the quality and quantity of sound produced is most governed by size and quantity of speakers. Thus, we have been evaluating several options for N & HO scales.

Sizes available : 1/2" dia. (expected 10/98); 3/4", 1", 1.1 x 1.7 all in stock; box type from PFM

Since most folks would like their installation in a single power unit this is where we have focused for now.

In narrow body HO diesels the optimum speaker location is the Cab area. For most units, combinations of 1" dia speakers with medicine bottle enclosures may work. Plastic bottle caps also work (David Hartman).

We used a LifeLike Proto SD-9 and installed two 1" speakers 1 facing up and 1 down. The speaker assy used a standard 1" dia medicine bottle for a cylindrical enclosure 5/16 long & a speaker at each end. This assy will fit into SD-9 cab area with speaker facing up & down. Frame modifications were also necessary, but the approach is doable and does not significantly compromise the loco or the installation. The 3/4" speakers will also work in the cab area. The 1/2" speaker coming in the fall may be used to project sound up through fan grills atop most diesel units.

For Dummy units in both N scale & HO there are two major options:

• Sealed units like box cars etc. can have several speakers floor mounted projecting down. HO can use the 1" or the 1.1 x 1.7 combos, N can use the 3/4" units.
• Unsealed units like dummy diesels with truck areas open will need to have enclosures fabricated. The medicine bottle methods are good and simple and you can use multiples as you choose or room permits.

I have used another method which allows a larger speaker that I call the Tent Box, see figure below.