I'm finally making progress with my Pi Sevens - the mid-horn cabinets are mostly done. I've been taking pictures, and I'll post some when I find the time...

I do think the panels seem quite resonant (at least they are pretty loud when I knock them with a knuckle). I'm wondering if there's space inside for me to glue on some sound-absorbing panel material (1/2" thick, comes in 48x96 sheets)? Or is there a better way to make the structure really dead? The cabinets are being built out of 3/4" MDF.

I expect to have the same question with the bass cabinets - how much can I reduce the internal volume with braces, sound deadening materials etc.?

For the bass I imagine the goal is to push the resonances above the range that will be excited by the woofer, but I'm not sure, so any advice will be appreciated.

Thanks for all your help,
tim