Hornby HM7000 TXS Sound Decoder on Accurascale Class 37 - How well does it work?

In recent videos I've been using a Hornby HM7000 TXS Sound Decoder in an Accurascale Class 37 model. This has sparked a number of questions as to how well this works and what the limitations. In this video I'll the details of the configuration I've used and what works and doesn't work with this configuration so it's time to take a closer look.

Sections:
00:00 - Introduction
00:36 - Configuration
01:33 - Speaker Limitations
03:40 - Lighting Limitations
05:38 - Summary
11:06 - Comparative Running Session

Configuration Used:
- Accurascale Class 37/6 37609 (DCC Ready version)
- Hornby 21-pin HM7000 TXS Sound decoder R7322
- Two speaker options used:
- Out of the box sugarcube with large cavity
- 8 ohm Base enhanced speaker
- DCC System: Hornby eLink + Railmaster
- Control Mode: HM7000 Bluetooth Application

In the course of all of my running sessions I kept my volume setting at no more than 50 (the max is 255) in order to ensure I was below the power threshold support.

Built-in Sugarcube Speaker
Note that the Accurascale Class 37 comes with an 8 ohm sugarcube speaker pre-fitted (it's not visible when you just remove the top hatch as it's under the PCB). This has a max power rating of 2W which exceeds the published power figure for the TXS sound decoder though it is unlikely you will achieve this with this speaker on it's own.

When Adding a Speaker
When you add a speaker, it will be in parallel with the sugarcube speaker so assuming it's an 8 ohm speaker the resulting impedence will be 4 ohms. Do not sue the Accuratrash speaker as this is a 4 ohm speaker and putting this in parallel will give a net impedence of

Removing the in-built Speaker
If your are unhappy with the built in sugarcube speaker, you can remove it altogether.
See this video from Roads and Rails which covers it's removal around 5 mins in.
   • Can The Accurascale Class 37 Sound Be...  .