Good idea or not?

[Peterjh]

I have a consist of two GP-38 locomotives .The one has a loksound decoder, the other a lok pilot decoder( no sound).

I thought of wiring an additional speaker to the existing sound decoder,running wires through to the second unit ,thus adding sound to the unit.Anyone done this before?I really cant afford to buy another sound decoder at poresent...

[peahrens]

I see no problem in doing so, except the fact that you will need to keep them coupled in operation.  Plus the connecting wires need to be routed somewhere and you would want to avoid having to drill scarring holes in the cowcatchers and damaging the appearance if separated.  I was able to do this with a SW7 dummy and a NW2 for lighting wires from the powered loco by routing the wires just next to the couplers and tacking them in place with a little CA.

On the speakers, use light gage (30 or so) decoder wire, some is more flexible than others.  You could include the teeny pin connectors to allow decoupling the locos as needed for operation or easier maintenance.  The LokSound Selects I use will handle 4 - 16 ohm speakers, just adjusting the volume downward more for the lower impedance setups.  If you can ID the impedance of the one you have, you can then decide how to add the second one; i.e., in series or parallel.  You will want to use the same ohms second speaker so they each provide 1/2 the amp power output.  If you have a 4 ohm installed (I think my Selects for awhile came with a 4 ohm oval) you would want to add the 2nd 4 ohm in series to yield 8 ohms the amp sees.  (In parallel the two ohms net would likely blow the amp.)  If you have a 8 ohm speaker installed, you can install the 2nd in parallel to yield 4 ohms for the amp, or in series for 16 ohms.  I would do parallel for 4 ohms which means turning down the volume more, but 16 would also work as I'd bet the volume would still get turned down, just less.

One interesting disadvantage is that with two decoders in consists, the LokSound diesel sound playback speed for that sound slot can be tweaked (very slightly) such that the two locos sounds do not run in unison, but slightly out of phase so each has its distinct sound at almost all times. 

So, it's about all the above and whether the advantages of the two decoders is worth $80 plus shipping.

[rrinker]

 This should work out fine. Then since you already have a Lokpilot in the non-sound one, when you can get a second sound decoder it should plug right in, and connect the speaker (removing the jumper wires between units).

                                  --Randy

 

[Peterjh]

Thanks Paul and Randy.I should be able to thread the very thin wire between the coupler and bodywithout too much trouble.The locos are Athearn RTR.

Re comment

"One interesting disadvantage is that with two decoders in consists, the LokSound diesel sound playback speed for that sound slot can be tweaked (very slightly) such that the two locos sounds do not run in unison, but slightly out of phase so each has its distinct sound at almost all times. "

I would like to attempt this out of phase tweaking.How would i go about this?I guess i should look on loksound manual ?Any idea where i would find how to do this ?I also dont have a lok programmer.

Apologies for all the questions.These are my first loksound decoder installs.

[jjdamnit]

Hello all,

In the August, 2016, issue of Model Railroader; pg. 57-59, there is an article on a similar project.

The author describes how to MU two switchers and add a second speaker, driven from one sound decoder.

Then in the September, 2016, issue; pg. 58-59, the same author goes on to describe how to speed match these two switchers.

Because these two issues are relatively recent it shouldn't be difficult to find them in print form or you can get them through the MR All Time Digital Archives (See the link on the masthead above).

Hope this helps.