Ding Ding,

Is this how your boxes started life..[or, something like!] http://jbl43.com/?pid=94861707 ?

Shows no 'trim' at the front - flat front edges.

As against http://blog.kenricksound.com/2015/09/jbl4343bwx_8.html

Shows those edges looking "very close" to what you have...!

In my packing to move.. I just can't quite lay my hands on all my drawings and measurements...