Hmmm well lets break it for you.
Treble and Bass, BOTH are the active ingredients to make a speaker. No speaker is complete without it, but then again there are seperate drivers/speakers which are made for specific purposes.
The Tweeter: It would only play the treble, no bass.
The Sub-Woofer, Mid Bass Driver: Meant to play the bass, no treble.
Now when these two come together a speaker set is born.
I assume you want a speaker set which isnt harsh to the ears and has good bass, there are a lot of speakers out there to please your need, BUT depends all on your budget.
I would say you spend atleast around 10k on a component speaker set and try to EQ the set, decreasing the treble and increasing the bass( thats what you want right? )
JBL P-608c or Fusion En-CM65 component set would suit your need.