Unless I misunderstand your question, you do not normally put lead shot in the SPEAKER itself, but in the speaker STAND. Adding lead shot to the speaker stand makes it more stable, anchors it better to the floor, and reduces resonance. I suppose you could add some sheets of lead inside the speaker cabinet if the cabinet is too resonant, but I haven't seen that done.
what if you put too much lead shot in your speaker
if you put too much shot in your speakers will it make them sound bad or just make the bass sound better?