Upgrading The Bachmann 158 Speaker
If you have sound in a new 158 or want to put sound in one you have probably considered upgrading the speakers. This page shows you how to access the built in speaker (or speakers) and replace them.
Start by fitting the decoder if you don't already have a sound decoder fitted. This fits under the panel underneath which just unclips. You can stop at this point and use the decoder with the built in speakers, or take the body off and upgrade the speakers.
Start by unscrewing the valance with a small screwdriver, then use guitar picks or other prising tools to slide between the body and chassis to release the clips so that it can be lifted off.
Undo all the screws holding the PCB to the model and lift it off. Also take out the two screws nearest the back of this board which hold the speaker underneath.
Solder the replacement speaker onto these two solder pads which are under the PCB.
The original run of the new 158's had 1 speaker, but 3 car units and the latest batch which have one at each end (pre wired through the plug and socket). For this reason its best to stick with 8 ohm speaker's, we recommend the 22x13x6 in each end because its small and fits in the same space as the original, but larger speakers could be used in the vestibule area if needed.
You can find the sound decoder on our website here.