DCC Impulses Column - 2
Steam loco and tender - in reality tenders don't make much
noise, but they are one of the best places to put speakers in
models.
Multiple diesel units with a single sound decoder - "MU
hoses" can carry audio between units to distribute the
sound across a lash-up.
Starting out, let me say that I'm going to deal with multiple
identical speakers in this column. I've tried larger (woofer) and
smaller (tweeter) speakers with crossover networks in mod-
els. Even in G scale, where I could use a 4” in the tender and
a 1-1/2" in the smoke box, I found the results were less than
what I wanted and certainly not worth the effort or expense.
In that case, the 4" provided a depth of sound that was only
diminished by trying to add a "tweeter."
Decoder specifications
Your decoder was designed to provide a certain amount of
audio power into a specific load impedance. A very common
2: Atlas HO scale S-2 loco with brass riser and plate for
mounting a TSU-750 Micro Tsunami decoder. The brass
conducts the heat from the decoder into the frame of the
loco and is glued together with thermally conductive epoxy.
1: N-scale Kato baggage car with (an older) DSX sound-
only decoder and two speakers to improve bass response.
1
rating is 1 watt into 8 ohms. Does this mean that you can't have
different load impedances? No. But the amplifier will change
based upon the load. Some of these changes may be good.
Some may be fatal to the amplifier or the speaker(s).
Lower impedance (4 ohms, for example) will increase the load
on the amplifier, making it work harder. It may be able to pro-
vide more power into the lower impedance: for example 1.5
watts into 4 ohms. The cost of this increased power is more
2
MRH-Jan 2014
