Speaker "face up" in tender, mount top or bottom?

[Percybigun]

I'm replacing the TTS speaker in my A4 with a 58 x 22 x 10 bass reflex speaker (8ohm 1w).
Even though its a "sound ready" tender with speaker mount, there is no holes in the chassis below speaker cone position, so i've decided to mount the new speaker "face up" and drill 1mm holes in the coal load (the tender is otherwise empty inside, no coal bunker partition, and the decoder is in the loco).
I figured its much easier to drill the holes in the coal load, than drilling the chassis!
My question is, shall i mount the bass reflex on the tender chassis, or directly underneath the coal load (sealed around its edge)?
If i do mount it on the chassis i will line the walls of the tender with lead so the whole tender becomes a sound chamber, the tender needs more weights anyway, and i've found that the lead lining enhances the sound quality (rather than bouncing around in a thin plastic box).
Which of the two options will give more bass performance?

[Howbi]

Well, PB, you are pioneering the process so you'll have to report back to us with the result of your experimentation as which way is best..........I don't recall anybody else installing a speaker into a lead lined tender......... 😀.........HB

[96RAF]

Here's mine...

The speaker enclosure is a Humbrol plastic paint tin with the top trimmed off.

Bigger holes in the hopper with 1mm holes in the actual plastic coal.

 

I have tried facing up and down and the important thing for the basic acoustics is to seal the front of the speaker from the back as best as possible.

 

/media/tinymce_upload/02845858acf5c6692c0df7792e514dc2.JPG

[Fishmanoz]

Good one Rob. But you should still be able to improve things further with Percy's bass reflex speaker. See other thread on improving things for TTS.

[WilliamDavid]

Interesting how this compares with the Zimo Sugarcube types.

I have fitted these in some A3s and A4s. Vast improvement.