I made this to house the speaker Guiliano recommends for testing.
I wanted something that made the speaker recessed in case you dropped it on a guitar. It could use a handle but it works well. I made mine out of TPU which does not work well in the AMS but prints well on its own. I did a test in PLA though and it was fine. I did some test drops on some spruce with the TPU one and it made no marks. I don't know about the PLA. Either way, don't drop it.
Put a little caulk in the hole after you put the wire in. You get a ton more bass power if it's totally sealed, it makes a big difference. I think I made it to print with the hole face up and it needed minimal support.
I think it's this 4 ohm speaker:
parts-express.com