floor standing speakers for surrounds?

Sorry i did jot put it.... b&w 804S.... front and looking at getting the same for the rear... or the older 804N... they say they go 38Hz - 22khz

Currently using cd1 book shelf for the rear

OK, those 804S are rated -3db at 38hz, but they are likely only flat down to 55hz or so. So, I would definitely cross them over to sub at 60 or 80hz.

Baranowski

If you have a receiver or preamp with room correction then start with that. I've been using Anthem gear for years. The ARC system crossed over my fronts at 60 and my surrounds at 110hz. That has to do more with the room response with the speakers than anything. So, 80 is a starting point but if you don't have room correction then you need to listen to music at different crossovers and see which sounds better. That is for the fronts. For the rears, 80 is usually excellent. Remember too that if you are listening to movies you want to send the LFE signal to the sub to allow your amp to breathe and better control your speakers above crossover. I wish I could tell you that X frequency is the magic dial but it's not that simple. If you are unsure or starting out then dial in your system at 80 and listen for a month and then you can start playing. I personally don't feel that full range all around offers significant value unless your room is really huge (35x25 and larger) and therefore you need to move more air in the room.

Mtrot is right with one addition, the crossover depends most on where your sub and fronts blend best. With music you generally want the speakers to run as full range as possible an with movies you want to supplement 80hz and below or 60hz and below with a sub. My Anthem allows me to do different crossovers between music ad movies. If your receiver or preamp allows for that ad well then I would start out with 80hz for movies and 60hz for music in your case.