Fabric store, and I just filled it in there, didn't use anything to hold it down. Remove the front grille, and the driver can just be unscrewed off. The wires are long enough that you can partially pull the driver out to gain access to the inside of the cabinet.
Actually, I found something I prefer to poly-fill--OLD PILLOW STUFFING. Now, I know this sounds weird but it's true with my sub. The trick is that you can't just use any stuffing from any pillow--especially new pillows. I was bored one day and decided to experiment. There was a very old pillow in my house--the kind that's stuffed with cotton-like material (don't know if it's cotton or not). Now, the pillow was so old and beat up that the stuffing had been "compressed"--exactly what it's like when you go to a cheap motel/hotel and complain that the pillows aren't fluffy any more. Anyway, I pulled out about half of the stuffing and replaced the poly-fill. The result? Half the old pillow is still in my SAWM40. The big difference to me was that it made the sub extremely difficult to localize. The key test for this is on material where you have explosions or other bass heavy material coming from the rear surrounds. With my pillow-stuffed Sony, there is no "hole" between where the surrounds roll-off and the sub kicks in.
I have a sony center channel speaker and stuffing worked wonders in that too. it sounded kinda harsh so i figured i would stuff it and see how it sounded. wow what a difference. the harshness is gone and the bass output is deffinetly improved. even my wife noticed a difference on this upgrade
I just wonder why sony isnt stuffing there speakers at the factory. could this make all their ssm-series speakers sound that much better? if so they might just might be a good deal. ?