I normally have my front's set to LARGE and my Center and Rears set to SMALL x-over @ 60 Hz. The built in x-over's in my 7001's send anything under 80Hz to the 10" subs that are built in regardless of the SMALL or LARGE setting.

Here's my question...

When I'm EQ'ing the 4 subs (i.e. LFE) I change the Front L&F to SMALL. Is there any reason to set the x-over any higher than 80Hz ?

Since your center and rears are at 60Hz, I'd think 80Hz would be fine.

Thanks Gonk. I needed someone to confirm that 80Hz made sense for me.

Actually...does the LFE channel carry info > 80Hz ? If it does then I should probably set to 100Hz or maybe 120Hz to play it safe.

The LFE channel will carry whatever gets put there by the sound engineer - up to and beyond 80Hz. You could bump the 990's crossover up to 120Hz (the highest point that the SMS-1's main EQ's can operate), but I'd still focus my attention at the lower frequencies first.