I want to use the Sony STRDH770 7.2 Stereo receiver with a set of Yamaha NS-SP1800BL 5.1 Speakers. The stereo is rated at 145 watts per channel and the Yamaha speakers are rated at 100 watts. I'm kind of new to home audio an have only set up an all in one DVD/stereo/speaker bundle. Would these speakers work with this stereo correctly running at 5.1 audio instead of 7.2? (My room doesn't have the space for 7.2 speakers)
If you do desire to get louder, consider getting a powered subwoofer. Then set the speaker size to "small". That will remove most of the bass, and therefore most of the wattage from the speakers. The subwoofer will have an internal amp that is sized appropriately for the required loudness.