It's ok when using mids....they really don't even need a box. So it's a good practice piece. Now when you start doing sub boxes, you want to make sure it's out of mdf, and air tight.


Instead of builing a box though, you should be taking the stock speakers out of the doors, building adapter plates with the plywood (if needed) and mounting the mids and highs there. Save the big bulky boxes for subwoofers.