speaker sizes for HO locomotives

Model Railroader General Discussion (Model Railroader)
1

Hi, Can anyone give me an idea of what size speakers I should use (or can fit) in the following HO locomotives:

PROTO 2000 SD60
SD50
GP38
GP9

ATLAS GP38
GP40
B40-8

KATO SD80MAC
SD45

I’m going to buy a large quantity of soundtraxx from loys toys and need to know what size speakers I should buy to go with it.

Thanks,
Jim

2

Dont forget the output of the decoder in watts versus the capacity of the speaker… you wont want to blow em.

3

Well, it is a more complicated question than you might think. If you put a speaker in the hood, you obviously cant fit a very big one. The place with the most room for a speaker is in the cab, but in order to do that you have to tear out the interior. Plus you will have a big speaker housing in the cab so you cant see through it. You have to decide which is more important to you, sound quality or detail.

EDIT:
Actually the best place to put speakers, usually 2, is in the fuel tank. But you need some pretty extensive milling machinery to make perfect circles the same size as the speaker, as well as slits for the sound to come out. This is the way BLI does thier new diesels.

4

I gotta ditto Joe on this one. The diesels I’ve heard with speakers downward-firing in the fuel taks are by far the best-sounding. But that’s probably not a DIY sort of project for any but the most advanced (and well-equipped) modeler. More an RTR consideration.

Casey

5

All of the locomotives you mention are going to require major surgery to fit a speaker of any size because the manufacturers fill every available space with weight. You may have to find someone with a milling machine who can grind cavities for speakers and decoders, or ship your locomotives to someone who performs custom installations, such as Bruce Petrarca at Litchfield Station.

I believe all 3 of these manufacturers also use split frames around their motors and mechanisms, and will require total disassembly to get to and isolate the motor.

A few years ago I installed decoders into four Kato NW-2 models. The only decoders that would come even close to fitting back then was the Lenz LE077, a dime-sized decoder. Even that required milling out a cavity for the decoder itself, and disassembly of the frame to get to the motor brushes and isolate them.

I have never tried sound installation in anything but P2K E-8 models because of this lack of space for speakers.