Yep
I have a Yamaha 2500 receiver as well. I am running full range towers but am also using a sub, which receives its signal from the lfe output on the receiver. I do have the yammie set to where it sends the low end to both sets of speakers, but keep the crossover set to 80hz. From there I tune it with the crossover on the sub itself, seeing as I rarely run it higher. The best thing to do is to experiment with as many different settings as you have time to try, and to also try moving the sub around your room. A lot of people do not take the time to do the latter, and it can really make a huge impact!