Thanks Shane, I know about that real MDF. I prefer the lightweight soft powdery shit from Brazil (homedepot) because it is so much lighter. But it burns up blades and router bits. Carl has already bought the MDF from BuilderSupply. We'll see how that looks. I need a new blade too. That Trek speaker killed my blade.
You are correct about the box resonance. The pass band is 20-50Hz. Double thickness MDF's resonance will be way higher than 100Hz, so it will not resonate. So we are only concerned with flexing under internal pressure, which will be significant. Bracing and wall thickness will minimize that. Maybe some angle steel or just vertical 2x4 braces screwed in. The side walls will only be 8inches tall, so they are no problem.
Using factory driver specs:
Qtc .5 = 90 liters
Qtc .55 = 65 liters
Qtc .71 = 34 liters
SPL at 25Hz
Q .5 = -9.64 dB.
Q .55 = -10.18 dB
Q .71= -12.48 dB
So of the boost switch gives 10dB we are all set. Just pick the Q to taste.
An interesting FAQ for subs.
http://www.diysubwoofers.org/faq.htmCarl is planning to build a pair of dual driver OB servo subs to place next to the main speakers for music. So deep bass for music will be very accurate. In that sense, would you recommend higher Q?
As for living with another person, I used to remember why, but it's been so long I forgot. Now I live with 4.
I have WT2 software, but it is a year old. I am registered so I'll try to download it. Thanks Mike!