Wayne Parham Messages: 18752 Registered: January 2001
Illuminati (33rd Degree)
You're right. I was replying to the first post in the thread, not the most current one.
I'll respond to your more recent comments this time.
I like using blocks of wood built-up to make a port. Your 2" drill bit is fine. The small difference between that and the 1.91" I.D. of the tube in the kit is inconsequential. There's more difference in other areas - a loudspeaker is a pretty wide-tolerace device with lots of electro-mechanico-acoustic shift in its paramaters.
As for re-positioning the port, the bookshelf model is small enough that standing waves line up in the upper midrange where the damping material does a pretty good job attenuating them. So I'd be reasonably comfortable with minor mods, and would expect little change. But we can't know without measurements, of course.
However, the tower model is a different story. The larger the box is made, the lower in frequency the standing waves modes line up. Large boxes tend to have standing wave nodes in the lower midrange, and these lower frequencies start passing through the damping material. It becomes less effective at lower frequencies. So we have to be more careful with placement of driver, port and damping material.