If you're looking for a full rehearsal audio solution, The Anchor Audio
MegaVox Packages are the best (and most affordable) options.
This soft cover is a great way to offer a light protection from the elements to your MegaVox speakers from Anchor audio, and to keep unruly students from messing with your valuable electronics outside of rehearsal. It's made of heavy-duty nylon, and it has a side compartment/pocket to hold small accessories (like a metronome!).
