Last time I measured the mid chamber, I just poured some small foam pellets into the chamber flush with the front baffle. I got 5.75 cups which was about 1.4 liters or so.
Today I completely removed the chamber, brought it inside and filled it up with small plastic lexan pellets to get a better reading.
It's exactly 5 cups. Which is 1.18 liters. So that's what you need to build it as. Maybe 1.25 L would be okay?
Where's the extra .75 cups (approx) from the earlier measurement? The diameter of the midrange cutout and the 3/4" thick baffle took extra pellets to fill.
Long story short, the midrange chamber should be 5 cups, once it's installed on the baffle, it will hold close to 5.75 cups.
Yes, I just measured something in audio with 'cups'!
I think everyone got the small piece of fiberglass that they had stuffed in the midrange chamber.
The other large piece I included in the box was just to show you what they had lining the walls of the main enclosure. There won't be enough for both boxes but you can use other types of fiberglass.
I'm going back out to box up more guts!