Two holes is understated, a minimalist mod that some people like. Four holes is the most popular configuration. I vent all the holes. On one project, I vented more than the ten that were there. I started punching in holes. There must have been 20 by the time I was done. I'm not so sure that was the most careful approach, but I just had to do it. It didn't improve the bass at all but I did feel like there was a significant upgrade in clarity.
Thee's the Bill I know. :D
I'm going to go try that. I'm just going to cut the plastic out, and have half of the support in there. I hope my hand doesn't slip like it did last time.