Your wattage figures for your speakers refer only to the maximum they can handle. Your Sony can only provide 100 watts maximum per channel so those 200 watt speakers are only half powered at maximum output by the Sony.
If more volume is desired, consider looking for highly sensitive speakers with numbers close to 100 dB rather than 90 dB. They will produce considerably more volume per watt.
For bass, obviously a high quality sub woofer is necessary. World class subwoofers are made by makers who specialize in them. Our frequent poster, jostenmeat, have posted much about them. Use the search feature to search for his references to such brands as SVS & HSU. Be prepared to spend over $500 for a sub to get a really capable one.
You can start with: http://www.hometheatershack.com/forums/subwoofer-tests/6015-index-subwoofer-tests-manufacturer-model.html
Aight. Right now I have up to three grand to drop on a new sound system. I am one for bargain buys right so hopefully shooting for a system twcie that value. I just need to know what to look for. Right now thisis what I have.
600 watt Sony STR-K67OP 5.1 surround sound
100 watts per channel
Right now for the left and right speakers I got two YAMAHA NS-A100XT tower speakers 200 watts each.
Then I have an audio splitter to a two channel PHILLIPS MCM 530/37 200W amp to two tower NLH 982T 200 watts speakers 8 ohms impedeance.
I know I have a lot of good components. Just not sure what to update to make this one hell of a system. I live in a college house, I need more bass and more decibels.