I played at an open mic last week with my Martin 00C-16GTAE and encountered, not surprisingly, quite a bit of feedback. Some tweaking with the preamp's phase switch and "notch" control made it playable, but it was still squeaky. I plan on doing a lot more live playing with that bass, so I decided it would be wise to invest in a soundhole cover. Doing my research on TB and in general, it looks like that's indeed the best move; people seem to have had success with the Planet Waves Screeching Halt and with Lute Hole covers. Since my sound hole is only 3 3/4" in diameter, I don't want to use the Planet Waves one (which is 4"). I'd rather not have to fight to get it in the soundhole (or take very long to do so), and I have no desire to mark up the edges of my soundhole any more than need be. This seems to leave me with Lute Hole. My question then is this: If I'm buying from Lute Hole, who makes wooden covers, does the wood choice make a big difference and, if so, which wood would be best for my bass? It's got a spruce top, mahogany back and sides, and a rosewood fingerboard. Specs on the bass are here, in case anything else might be of service. It says the neck is a "select hardwood," but it looks like mahogany too. http://www.martinguitar.com/guitars/item/479-00c-16gtae-bass.html#tab2 Their woods (on a plain, undesigned cover, or "mute hole," as they call it) are as follows: $29 for maple or walnut; $55 for spruce, koa or mahogany; $75 for roswood or cocobolo. More info here if so inclined. http://www.lutehole.com/customshop.php A bit pricy for the woods that are on my bass (and potentially in general), but if it's worth it I guess I'll pay up. I do love my acoustic bass. Thoughts or suggestions are much appreciated!