Two or More Subwoofers?

I have never heard of altitude affecting speaker performance. I was mile
high way back in grad school and things sound pretty good at RMAF - are
they rocky mountain high on altitude steroids?

. I know it takes a higher temperature to boil water. Is this a planer thing?

Not sure, but a Magnepan has a considerable amount of panel surface area, especially the bass panels which are probably 75% of the total area. Being over 5,000 ft higher in the Denver area I assume that the density of air is lower meaning that it is less work overall for the amps to move the panels; but I'm no physicist!

Thanks Stickman

Envious of your current and future room

I have a 15x27 room and that extra 3 feet would really be ideal.

What area of the foothills are you in?

Castle Rock