Try the Audiophiliac's simple experiments, and you might get better sound. It's easy to do, and it's free.
One great thing about Bluetooth speakers is you can use them to learn about how room size and acoustics affect a given speaker's sound quality. Experiment with placement and you'll quickly learn that where you put a speaker in a room can make a big difference in the sound, for better or worse. That's true for all speakers, but since BT speakers tend to be small and light, they're easier to move around.
Start by putting the speaker on the floor in the middle of the room, and you'll hear that it makes more bass than it does sitting on a table. It will also probably sound dull and lacking in detail down there. Next, try putting the speaker in a corner, on the floor, and it will make even more bass. After that, try putting it on a table in the corner, and you'll get back the missing treble, but the speaker will probably sound better a couple of feet away from the corner. Move the speaker to each wall in the room, again at the same 3-foot height, and see if one wall sounds better than the others. Then move it a foot at a time along that wall, and you might see that one or two spots might be better than the others. So you see, everything changes the sound; a little experimentation might yield surprising results.
Battery-powered Bluetooth speakers are the easiest to move about, but if you move any speaker from a large room to a small tiled bathroom, and don't adjust the volume control, you'll be surprised how much louder the speaker sounds. Without adjusting the volume setting, take the speaker outside; it will seem much quieter, and you might not even hear it outdoors. Again, the environment changes the way a speaker sounds -- and the differences are far from subtle.
Of course, you can try the same experiments with wired speakers; it's just a little harder to do, but definitely worth the effort. The better the speaker, the bigger the differences you're likely to hear as you change positions, and the changes will be more pronounced with stereo speakers (BT speakers are nearly always mono or single-speaker systems).
After you try out some changes, please share your experiences in the comments section below.