Center Channel Dialogue

I am looking for suggestions to increase the comprehension of vocals for my center channel. I realize many movies and programs are produced such that understanding the dialogue can be a challenge. 

My home theater is mostly Martin Logan: Summit X front, reQuest surround, LX 16 rear surround, SVS and Velodyne subs, and a Stage center. The amp for the Summits is a Pass XA30, all others use an Earthquake Cinenova Grande amp with over 300 watts/channel.

My issue is that I have to cup my hands over my ears to understand the dialogue. I have adjusted the Marantz 8801 pre/pro to maximize the output. I also use one channel of an equalizer to further increase output, and have also adjusted the different frequencies trying to improve dialogue.

I've angled and raised the Stage center the best I could. 

My question is, should I look at different center speakers? I like having all electrostats, and wonder if a substitute non-electrostat would match? Would a horn center like Klipsch make sense? 

Recently I considered a DBX expander, but don't know if that would help or hurt.

BTW, it's tiring holding my hands over my ears to understand the dialogue:)

I appreciate any suggestions.