Heljan O gauge Class 45 diesel - DCC sound with custom 3D-printed speaker enclosure = failure!

Demonstrated here is a custom-designed & 3D-printed speaker enclosure, featuring a labyrinthine back-port (in an attempt to further lengthen the path between the front and rear of the speaker), for a Visaton FRS5 speaker - 50mm diameter cone, impedance 8 Ohms and max. rated power of 8 Watts.
In theory, plenty big enough for the intended model (Heljan O gauge Class 45) and DCC sound decoder (Zimo MX696) from Digitrains (Paul Chetter Actidrive).
So what’s the problem then? It’s the bloomin’ body!
Not that it doesn’t fit - the enclosure design allowed for both the width and height inside the body - No, it’s the acoustics (or rather the lack of them).
Even with the enclosure being ported, the speaker is firing directly into the chassis and roof. The body just muffles the sound (a bit like a mute for a trumpet) and completely kills the dynamic range that this speaker is clearly capable of (sounded great before I put the body on). 😢
See follow-up video for the solution:
• Heljan O gauge Class 4...