RM 6880,Onkyo 805 - LFE frequency

[jingoboy_78]

Hi all,

I am using a RM 6880 satelite 5.1 speaker system paired with onkyo 805.I have connected the sub using the polk way(using the speaker level inputs).Also I did the auto calibration using the receiver microphone and it detected all my settings except for the LPF/LFE frequency.
You can find this in the speaker menu => Speaker settings
Does anybody know what should be this frequency.I guess I have options from 80 HZ(THX), 90 HZ, 100 HZ, 120 HZ.I am using 100 HZ right now and its sounds ok.Any body knows how to tweak this system better? What should be the volume of the sub(can I turn it all the way up?) right now I have 3/4th of the volume.
Any body knows how to tweak this system better?any suggestions are welcome

Sorry if this is a dumb question and please help as I am a newbie.

Thanks,
Jingo.