Hola. One of the most interesting and wise design, and a wonderful feature from Martin Logan, is to have the speaker's diaphragm direct to our ears, and nothing between them, just the air. Any fabric will dull the sound. If you can not tell the difference in the quality sound, its your ears. I can tell, Dave can tell, Gordon can tell, in other words, we can tell a huge, enormous, big, impressive, long, great, gigantic, massive, astronomical, considerable, extensive difference in the sound quality without the cover. This is the reason why we do not use any cover while we are listening the musician(s) playing for us in our system. With the cover on, you spoil the stage, and the size of the instruments too. You can't get the fun that the musician(s) are having, playing their instruments or singing along.
If you feel that you do not need to remove the cover, its OK too. Its your system. Do not worry about us, the crazy users. Just enjoy your music! Happy listening.