I figured out a long time ago that Polk is not going to build any more SDA's. I finally want something different so I am building my own. Picture this, two line arrays of 12 5.25" drivers and maybe a passive radiator and some Vifa tweeters with a hacked up 1.2 crossover. The drivers are due in today and I picked box sizes that require minimal cutting of the wood used. I wish there were a tech person interested in talking design but I will probably have to just take my best shot and see where I end up. This should take awhile. I'm sure some polk engineer is laughing at this one.