Madisound speaker upgrade question (self resolved).

 Well, like you may have found adding a speaker baffle can tighten the low end sound. Sometimes the sound is greatly improved if:

 The speaker has the low end-

 sound was leaking out all over especially infront of the speaker where it might cancel-

 the chamber was too big otherwise-

 things were loose in there rattling around-

Sometimes venting a enclosure can help increase low end. Just not usually the case with small ones.

I actually asked my sister-in-law, who designs sound systems. She checked one of her speaker forums. There was a thread on speakers in trains. It addressed baffling and that it could improve the low end. I still don't think I will reopen the GP9 I put PS2 in, but I wish I'd baffled it while upgrading!

I have used a PVC pipe cap of the appropriate size as an enclosure which works well if there is room

Caps from spray bottles work well as baffles, and you can cut them down if they're too tall.