how to fill bassreflex box

[adeel]

i just purchased floor standing speakers with a jbl woofer of performance series p150sw i opened the box and found no acoustic material inside the box i want to know i should fill it with acoustic material or i should not fill it my box is bass reflex type with a bassreflex behind the speakers . ??????????

[CraigV]

Give the speaker time to break in with use. Play it, and see how it sounds. If you like the way it sounds, leave it. If not, go to Wal-Mart & buy some polyfill in the craft section. Fill the box ½ to 2/3 and see if it makes a difference that you like. Leave a space to the opening of the port, or your bass response will suffer. If you don’t like it, you’re only out a few dollars, and you can remove it easily.

[Highbar]

Speakers are designed to work from the manufacturer, they don't have to have any treatments inside. I'd leave them as they are.