better center channel?

[scuba_d]

Here is my dilemma. I have two of these Yamaha NS-AP9500S's that do an ok job on their own as a center speaker but I would like to combine the two into one super center speaker. Please check out the pics here I don't know if you can see in the photos but the speakers are arranged in a mwtwm configuration even though all drivers are 4" with a 3/4" soft dome tweeter. The 4 speakers and 1 tweeter have their own crossover and have a final imp of 8 ohm, so wiring two together in parallel would give me a 4 ohm center instead of an 8 ohm (I know my stereo can handle it because I have 4 front speakers in parallel running at 4 ohms per side). I was thinking of designing the center speaker to be the complete width of the TV that it is going to go above and that total length is 53" since I will have 8 speakers and 2 tweeters to put in it. I really want to do the design on the bottom of this page SLA but I am not sure it will sound as good as I think. I was also throwing around the idea of making the arc design go the other way (convex in lieu of concave). These are the other two options for the design I had, I would have to modify them of course to work for my amount of speakers and so on. DIY Center Channel Speaker with HiVi F5 and SD1.1A ,Cynosure Center Channel Speaker DIY Project. I am looking to get some peoples input to see which is the better way to go before I start my design work on the cabinet for the speakers to go into. Let me know good bad or indifferent what you think about the design I want to go with compared to the other two I have come across.