I'm doing some midi orchestral work and I have about five instances of QL Spaces running.  For each track that I have Spaces running I have EQ set up with a high pass filter to get rid of some of the lows building up.  My question is should I have the EQ before Spaces or after in the FX bin or is there another direction I should be heading?  I know that EQ is really up to one's taste but I'm just looking for some general advice.
 
Aric

Try both and let your ears decide where they should be. There are no rules, just Steak! Wait, that's an Outback commercial :))))
 
That said, I usually place filters at the Beginning OR at the End of the effect chain and sometimes in Both places.
 
CJ

Depends on what you're trying to do and how much EQ you're adding. If you put the EQ before reverb, then the low frequencies won't enter into the reverb, and won't be reverberated. As I assume you're not using a brickwall filter, than some mids will be reverberated less as well. If the EQ is after the reverb, everything is being reverberated, but you're removing the lows after the fact.
 
The audible results may or may not be similar. But if you reduce frequencies going into the reverb, then you'll be able to pump more signal into the reverb overall.

This wasn't part of your question, but just as an aside: if you're using basically the same hi-pass filter and reverb on several tracks, then send these tracks to a bus, with only one instance of the EQ/Reverb combination running on the bus.  Slightly more efficient, and you avoid making multiple similar changes every time you need to tweak the EQ and/or reverb. 

My understanding is this, if you are trying to simulate a room sound EQ the verb not the source.  For example you roll off some of the top end to about 4khz and roll off the bottom between 80-400hz.  Depending on the size of the room you are trying to simulate.
 
Ben

I agree with Craig on this.  It is better to not even allow the bass frequencies into the room at all. The reverb will sound better compared to letting them in and then trying to remove them later.
 
If you think about it you can see it. Imagine letting all the low end into the room. Now the reverb has to process all that stuff in conjunction with the  mids and highs. More work to do, reverb quality will be effected too. But prevent the bass from going in and bouncing around the room and now the reverb is only dealing with higher ranges and no low stuff. It has to come out sounding better.
 
Some reverbs have EQ before and after and that is even better because then you can fine tune the reverb sound before it goes in and after it comes out and is returned to your mix.
 
Would you set up a bass player in a big boomy live wet room. Probably not so why allow him (or any real low frequencies from anything) to go into the reverb as well.  I know may reverbs can adjust how they respond to low frequencies but it still sounds a little cleaner when you don't let them in the first place.