too much noise, but don't know why

hello,

I have a customer who wanted better wireless range in his house. its a fairly large house 3500-4000 sqft one story.

So I decided to try out a idea that I had herd about, I bought a cisco wireless router 851w , a signal splitter , a 20 foot lmr-400 , 50 foot lmr 400 , and two cisco high gain ceiling mount antennas . the LMR 400 already had N-type on both ends so I got n type to rptnc adaters for all ends, and male to male rptnc for where the antennas connected.

the 20 foot works perfect, at that point I have the slipter, and one antenna hooked up. from there I have the 50 foot extension, and then the other antenna, and I barely get any gain. this all of coarse it up in the ceiling. So I pulled the 50 footer out, ran it on the floor and it works perfect.

so question is, why am I loosing so much from being in the ceiling, and am I missing something obvious?