Ok thanks Kal..I emailed klipsch tech guy and he is about right on with your recommendations...heres his email response...
Thanks for writing. The auto-setup of receivers frequently gets this wrong.
I recommend using either 80 Hz, which is the THX recommended frequency, or 20 Hz above the speaker's -3 db down point, whichever is greater. Here is an example from your system
CF3 is down -3 db at 35 Hz per it's spec sheet. We want to cross it over up where the response is still flat so 35 + 20 = 55, we'll use 60 Hz. It can easily handle this frequency but it still will send about 1 ½ octaves to the sub IF this speaker is set to SMALL setting on the setup controls.
KSF-C5 surround is -3 db at 63 Hz. 63 +20 is pretty close to 80 so use that. This cuts 2 octaves of bass from the surrounds, rerouting it to the sub. This cleans up the sound of the surrounds because they won't be trying to play notes they can't handle. It also will give them much more power handling capability because the powerful bass is limited.
The crossover on the sub should be rotated fully clockwise. We do not want it's filter to operate at all, basically we're telling the sub to play whatever the receiver sends you'. The sub will be playing the .1 part of the soundtrack (Low Frequency Effects) and any of the bass that has been stri
I recommend going through all this setup, THEN trigger your auto setup with this portion of speaker setup SWITCHED OFF. Otherwise the first thing the receiver will do is to reset to the previous faulty parameters. You can use the optimizer to set distance, level, and eq, but don't trust it to do the setup. Usually you can toggle which features you wish the optimizer to run. See your receiver's manual for more details.
Klipsch Heritage and Pro Audio Specialist
Home Audio / Theatre Technical Support