i have a pioneer VSX-D503S, it's about 15 years old, but does have an input for rear, front and center speakers and says you can connect a super woofer system (such as a pioneer S-W1000) to the front speaker terminals. it has dolby pro logic surround and dolby 3 ch logic center modes. looks like it has 110 watts per channel in stero mode; 20W + 20W rear, 75W + 75W front and 75W center in dolby pro logic surround.. i was wondering if this is worth keeping or should i update to a newer 6.1 or 7.1 system, which would be best? i was looking at the PIONEER VSX-516-K or the 515 which are both about $170 shipped