So I opened my rattling box today and found a few things:
1. The box is made of 3/4 inch MDF.
2. Lots of hot glue used inside.
3. Driver magnet is not shielded.
4. There is no acoustic dampening material inside.
5. Whoever assembled this piece lacks marksmanship.
here are some pictures:
Lots of hot glue inside and no acoustic dampening:
No shielding on the driver's magnet:
I guess the port-tube is easy to fix, the question is should I put some acoustic dampening material?
Hopefully, people will find this post useful.