Soundtraxx equipped GP38s

Ya know, there are those moments when everything comes together and it's all worthwhile. As I have shared, I am thrilled about the sound of the Soundtraxx EMD decoders. I think they are the closest to capturing the feel of any out on the market. As such, I have installed a few in my locos. However, running 2 identically equipped units in MU tends to have both sounds be identical (of course), and almost defeats the purpose of having multiple sound decoders in multiple units MU'ed together. So with the release of the non-turbo 645, I tried something different. I have to GP38's that I wanted to MU for my local job. So I installed a 567 (non-turbo) in one of my GP38's and I put a 645 non-turbo in the other. I figured the sounds are similar, but enough different to emulate the differences found in prototype locomotives.

Guess what? It worked!

MU both units together, and they spool up and spin down in ~similar~ but not identical fashion. Also the sound recordings are enough different that it gives a unique flavor to each engine. The 567 sound has more of a sharp glug-glug, sorta like the valves are a bit out of spec, while the 645 non-T has a much smoother sound. Also, the 645 non-t decoder sound tends to pause at each notch for a moment when winding down, while the 567 just drops through all the RPMs smoothly. Running them together truly gives them the sound of two very similar but not identical machines working in tandem. Even when idling, the effects are very noticible. The results are stunning. A treat for the ears.

I did do some things to assure the sounds were still running the same as would a real lashup of engines. I set both "engine control" CVs the same, so notching is done at the same speed steps. When engines run in MU, the share the same speed step controls and notching happens at the same time. I also made sure both lokies had the same accel/decel/and BEMF motor controls. As such they run virtually identically.

Anyway, wanted to share this with the group. Great time to be in the hobby!

Category:

Autos & Vehicles

Tags:

• Sountraxx
• Tsunami
• 567
• 645
• non-turbo
• great
• northwestern
• railway

[engineerside]

I'm interested in how much of the weight did you have to shave off for the speaker? I have 2 PROTO 2000 GP38-2's CSX that I really like. I'm changed some running gear, but would like sound. Was it difficult? do you have a vid on that? (Sorry for so many questions)

[GreatNorthwesternRwy]

@engineerside ,

The Athearn units stuffed the weights in the area where the dynamic brakes would be. I had to take all that out as well as remove the plastic in that area to make room for the decoder. The non-DB piece was trimmed back to just what would fill in the hood space. The area under the fans was used for the speaker.

The P2K will be a bit more of a project. I did one of those and ended up having to take the unit apart, down to the frame, and cut away enough metal to provide space.

[Patriotvb]

What speakers did you use?

[GreatNorthwesternRwy]

@Patriotvb ,

I used a standard "medium oval" speaker. I think the dimensions are nominally 3/4" x 1". The speakers do have an enclosure. I mounted them in the rear of the unit; the sound comes out through the space between the truck and the frame.

[ggspin12]

are these Tsunami or just the regular 101LC's?

[GreatNorthwesternRwy]

These are Tsunamis. One is the non-turb 567, the other a non-turbo 645 series.

[TMandN]

Just bought the Tsunami 645 non- turbo decoder, and had to check this video out.I like what I hear!!!Mine is going into a CPRail GP38-2 Bluebox, that has been remotored,and nickle silver wheels added.Not much room inside, so Ill have to use the smaller Soundtraxx oval speaker.Thanks for a look at your video!!!!!

[therealsnow]

sounds great!

[foxden1992]

A treat for not only the ears, but also the eyes. Your locos are both really detailed!

[ggspin12]

ah ok, that would explain the more prototypical sounds, thanx!