Hornby Class 43 HST DCC & TTS Sound Speaker Upgrade or Replacement (R3602TTS)

Hornby have just released a brand new Class 43/HST set with TTS sound. It’s a fantastic model and the sound decoder is pretty decent too for the money, but, as is the case with most sound decoders, the factory-fitted speaker is a little tinny and doesn’t have much bass response to it.

In this in-depth video, I show you all you need to know about upgrading/replacing stock TTS & DCC sound speakers with a far superior Mega Bass speaker, including rewiring, body preparation (for anyone who doesn’t have a sound-fitted model) and installation. The improvement to sound and bass response from these new speakers is fantastic.

The HST set featured in the video is not a TTS-fitted model, however the steps involved in replacing the speaker are exactly the same for a TTS chip as they are a LokSound or Zimo decoder.

We look at both TTS and LokSound V4 decoders; the only difference being that a TTS (and Zimo) decoders must use an 8 ohm speaker, while the LokSound V4 can use anything between 4 and 16 ohms.

Speaker impedance and decoder specifications are explained in more detail in our free guide, which you can download here:

Looking to buy replacement speakers?

There are a variety of different retailers selling Mega Bass speakers (also called ‘High Bass’). Here are some options:

* Megabass speakers on AliExpress

Megabass speakers on eBay

* Highbass speakers from Coasal DCC


Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.