just because you've stuffed a few shirts into the port holes doesn't make it a sealed box. A sealed box must be air tight and belive it or not, the air can still pass through your shirts. I agree with ThunderTunes in saying that ported and bandpass is better for loudness but I think you will find that ported gives much puncher and cleaner bass. Sealed is good if space is at a premium and you are after sound quality. A nice think peice of MDF would do a good job if placed it where you wanted the glass to go but it wouldn't look as good.
Hope this helped.
Old enough to do it, young enough to do it again.