Wayne Parham Messages: 18783 Registered: January 2001
Illuminati (33rd Degree)
You definitely don't want cabinets with any plywood other than Baltic Birch. Those voids aren't just a problem structurally - even more important to the sound - they are a problem acoustically. Debris breaks off within the voids and it buzzes. That's a very common problem for speakers made with plywood. So use either Baltic Birch plywood or MDF/HDF.
To tell the truth, MDF is actually better than Baltic Birch for sound. It is nearly a homogenous mix of wood pulp and glue so its resonant properties are easier to deal with. Knock on it with your knuckle and you'll hear what I mean - it's a dead thud. Most wood panels give a sharper rap, which clouds the midrange and give a distinctive "boxy" sound. So MDF to me is the best material to use unless the speaker will be moved a lot or subjected to high humidity, in which case I would suggest Baltic Birch.