Adding sub question

Big difference. The Marantz is a full-blown MC processor which includes Audyssey EQ. Perhaps overkill for you.

The Parasound is more appropriate. You can put a pair of "Y"connectors at the output of the Classe, sending both channels to the ARC and the other pair of channels to the Parasound for its crossover. However, you do not get any EQ for the subs this way.

Let me suggest another alternative: Use the "Y" connectors as above but get an DSPeaker Anti-Mode 2.0 Dual Core digital room equalizer ($1099) which will give you both a crossover and a good EQ for the subs.

I thought about the y connector but my Classe has both balanced and single ended outputs, I am currently using balanced to the ARC, I was going to hook the single ended outputs to the sub inputs, but was hesitant about doing this as my main speakers would still be getting a full range signal. Would this still be ok to have the full range go to mains and set the low pass on sub at say 80 hertz or so? I love the Classe and hate to get rid of it as it sounds awesome with the ARC(and is a solid 8/10 condition)would it get too `busy` in the low end doing it this way? Reason for wanting to add a pair of subs is I kind of like alot of low end, and I have to push the Tylers a little to get them to go deep like the are able to do.

I am sorry that I misread your original where you said that you wanted to "keep the full range signal from my main speakers." I read "to my main speakers."

So, the use of a dedicated sub crossover would be what you want and the P2100 would do that, albeit without the valuable EQ.

There used to be good dedicated sub crossovers on the market but they have disappeared. If you can find an NHT somewhere, they were great and cheap enough to let you add an AntiMode 8033 for EQ. I also recommend adding the 8033 to the P2100, if you can.