correct box?

dallaire

Member
2007-12-01 12:51 am
Hi all, I am finally getting ready to start cutting wood. I have purchased the SL Audio WT2 speaker tester package and have got all my first run parameters in order. I have entered the speaker parameters into "WinISD" freeware program and arrived at a box dimension and tune frequency per the programs reccomendations. My question is this. When this program kicks out the dimensions for box dimensions, it does'nt seem to factor anything for diplacement for driver on the rear of the frame. In my case this is a six in peerless woofer. also no cross bracing or what about the port tube? does the port displacement just count the thickness of the port walls? or do you take the whole port displacement as if it were a "solid" cylinder, instead of a "tube"? This is just a test box I am making to start with so perhaps I shoud build it big and add solid pieces of mdf to get volume correct?
Thanks,
dallaire
 
Hi,
the volume "inside" the port does not count towards the box volume.

All the bits that occupy wasted volume must be totalled up; bracing, corner battens, speaker basket, speaker magnet, speaker cone, port tube and port.
Add these to the vented box volume from your WINisd model and then add another 10% of the total. [Box volume + wasted volume + port volume]*1.1 = cabinet internal volume.
Now add on the wall thickness of each of the panels and determine suitable panel sizes.