Jim - what was the shelf you used to raise your TV?
Raising the TV was my solution - but I have a 65" TV so instead of a shelf I used this http://www.amazon.com/38-LED-LCD-Mounting-System/dp/B007T01G98/ref=sr_1_16?ie=UTF8&qid=1353743621&sr=8-16&keywords=Transdeco
. It's essentially a wall mount on a floor-stand. I left the middle shelf off and put the floor-stand behind my current TV cabinet. The base of the floor-stand is less than 3" high so it fits under the TV cabinet.
It looks a bit pricey at first but kind of works out - a good tilting/rotating wall mount often costs $200 or more if you include the install, and it's still cheaper than a lot of new center speakers. The big pluses for me are I can easily move the TV or take the floor-stand/mount with me if I move, and it's height adjustable so when I get my perfect center I can put the TV at just-the-right height ; )