This article explains several methods to make smaller Bluetooth speakers louder and enjoy your music even more.
How to Make a Loud Bluetooth Speaker for Just $6 [Easy & Cheap]
Bluetooth speakers are portable devices. Their small size gives them less amplification power than their larger cousins.
Sound is a form of energy and follows the inverse square law, which states that the intensity of sound decreases by about six decibels for every doubling of the distance from the sound source. The effect is the opposite when you bring the sound source closer.
A Bluetooth speaker in a larger room or open space will sound different than a speaker in a small room. Sound dissipates over distance, so the sound quality will depend on the size of the room and other variables such as the material of the walls and floors.