Hi all! Well, I finally got my box built (2 of them, actually). I have no clue what happened, but I just calculated the enclosure volume, and considering bracing and such, I'm left with 118L's worth of volume. I was aiming to get 150L's. Anyway... this is not so bad. Since I won't be using flared port ends, and since the port is rather smallish (4"), it seems I won't get any turbulence at the power levels I'll use. Besides, group delay dropped down considerably. Anyway... while I was playing around with Unibox, I found out using different damping techiques affects frequency response a lot. From "No fill" to "Heavy fill", apparently I end up losing around 10 Hz of F3. Not good. I think. Then again, why does Adire tells you to use "heavy fill" on their designs? I'm not sure about this. Should I use polyfill on my vented box? Cover the box walls with something? And, if I do so, what's the correct ratio to use? I'm a bit confused.... thanks for any help! Javier.