Don't worry about not getting back to me sooner... all is well.

You brought up a good point in that the relationship between center of the HF driver and the woofer needs to stay constant (and Wayne confirmed that with all that mathematical calculation -thanks Wayne). What this means is that I need to be carefull when building the enclosure to house the horn. So goodbye to fancy horns such as this ones: http://www.acoustichorn.com/

I ended up using BB-ply from Commonwealth lumber. Getting the 5x5 wood home was quite a challenge... I ended up putting the wood on the roof rack of the van.

To install the T-nuts, do I just drill the hole the size of the cylindrical barrel and let the pressure of the screw drive the prongs into the wood?

Thanks,

Norbert