I am all about the spirit of DIY, but I am also pragmatic.
For those of you that want the ~ 31 Hz "music" tune, and don't have the time, skills or money to build, you might want to consider one of these:
At $165 delivered
, they are a steal with a slightly smaller footprint, similar tuning (F3 of 29 Hz), high sensitivity and power handling, etc.
I have two of these in my fair weather outdoor system. I am driving them with a bridged Crown XLS 1502 and they rock the entire block!
It costs about the same to build, and you get carry handles, carpet finish, speakon connector, corner protectors, etc. They may not look as good as a DIY finish, but it is tough to beat them for the money. They even have lesser versions of under $130 delivered.
Just throwing that out there as something to consider depending on the constraints one has.