SoundTraxx LC Series Owners Manual - Manual (Page 8)

LC SERIES DIGITAL SOUND DECODER OWNER’S MANUAL 8
5. To ensure the most accurate measurement, be sure that the power pack voltage
remains at the voltage set in Step 1 of this test.
6. Measure the current the locomotive is drawing while the motor is stalled. This is the
stall current and must be less than the decoder’s rated capacity.
Step 3. Plan the Installation
You should give some thought to where the installation of the various DSD-LC components will
be within the locomotive before you get started. Figure 2 shows typical installations for a steam
and diesel locomotive.
Figure 2 - Typical Sound Installations
Speaker Considerations
You will want to use the largest speaker possible to get the best volume and bass response.
The decision most critical to the success of your installation will be where to put the speaker.
Obviously, the ‘where’ of speaker installation will depend on the size and type of the locomotive.
But when considering the speaker’s location, remember that the volume of the speaker will be
greatly enhanced when the speaker is fitted into a small airtight enclosure with the front of the
speaker open to surrounding air. The reason for this is simple: in order to generate any apprecia-
ble sound, the speaker must develop air pressure. Without an enclosure, an opposite pressure
behind the speaker cancels any pressure developed by the front of the speaker. The enclosure
isolates the front and back surfaces of the speaker, thereby increasing the sound pressure and
hence, the volume.
Additionally, the enclosure must be sized proportionally to the speaker such that the volume of
air enclosed is several times larger than the speaker diameter. If an enclosure is too small, it will
interfere with the speaker operation and although it cannot be made too large, there is a point of
Backup Light
Right Rail Pickup
usually connects
to locomotive frame
Headlight
Digital
Sound
Decoder
Speaker
Left Rail Pickup
usually connects
to tender frame
Blue
White
Motor (+) Lead
Motor (-) Lead
Red
Gray
Orange
Black
Yellow
Blue
Black
Headlight Blue
Blue
Yellow
White
Motor (+) Lead
Motor (-) Lead
Red
Gray
Orange
Tan or Purple
Tan or
Purple
Speaker (under fan
grill or in cab)
JUMPER WIRE BETWEEN TRUCKS
Digital Sound Decoder Backup
light