Hopefully I can build the measurement rig within the next two weeks, but with my apartment lease still delayed due to unexpected renovation issues, that'll have to wait until I get settled in. I am curious myself to see the FR of how I tuned them, but I'm more interested in seeing the spectral decay.
REW is not so good at spectral decay. To get full range you have to make the time window too long; decrease it and you have to truncate the bass end of the spectrum. On the other hand, REW does a good job for SPL and spectrograms...and it's FREE (but make a small donation :) In addition to ARTA/Crossover, FuzzMeasure is slick. I did the free trial. It costs a bit to get full use (save a file, etc.) but I donated the same amount to REW for their free software. I think I'll pull out my old Dell laptop, clean out all the junk, buy FuzzMeasure, and give it another try.
BTW, thanks for clarifying your progress, plans, and methods. Very interesting, for sure. If I'm not mistaken, someone posted something about using epoxy directly on inside of the cups for stiffening. Maybe do a Ludoo search, if interested. Dynamat has been tried in the cups but Not sandwiched between the cups and a layer of epoxy.
Sounds like we're in the same ball park RE: size/number of bass ports. A rough calculation suggests I'd like 2 or 3 of your 1/16 holes most of the time, sometimes one to none, and anything over approximately 75% of one cup vent slot open and the rest of that one and the others closed has about the same effect as all 4 open (with stock internal felt in place). I've also found it useful, at times, to make 2 smaller bass ports, one in the center of the top and bottom cup vent slot. I don't recall if I posted that or if I sent it to someone by PM. I am aware that Round bass ports are better/more efficient than Square bass ports of the same size but I have always tried to make mods that are reversible. I am, however, going to try your method in an extra set of cups lying around.
Anyway, thanks for the novel ideas...and for sharing them!
Edited by bluemonkeyflyer - 5/28/13 at 3:54pm