the strength doesn't come from the screws, it comes form the glue.. and yellow carpenters glue will form a bond that is stronger than the wood it's self.

 

as long as you don't put a nail any closer than 2inches form the edge
splitting should not be an issue
and yes the glue is what hold the box together

 

Well, I still think it will not work with just glue and brads... I have had professional cabinet makers make me boxes and they first tried the brad and glue which they also said will bond and make it stronger than the wood and after a few hards burbs it busted the seams in a few places... They have tried different cuts to make it stonger and after it was all said and done I added screws to fix it and make it strong...

If under serious SPL add screws if just average SPL it might work.

 

i've built boxes for w7's and hcca's for people running 2500 watts plus and no blown boxes yet

 

maybe they weren't using s suitable glue.. standard white glue isn't strong enough.. a yellow carpenters glue should be used. I can take 2 pieces bonded at a 90 degree angle with glue, and hit them with a hammer.. the wood always breaks before the glue lets go.