Today, I have spent some considerable time on the phone/Email to REL. I would like to share what I have learnt about my STRATA 5 that is not covered by the user manual. This may or may not be common knowledge, however, I could not find any answers in the forums. 1) The frequency adjustment is for the hi-level input only and does not affect the LFE input in any way. So the LFE input is not filtered through the sub's crossover regardless of the setting. 2) The frequency should generally be set -3DB or -4DB below the "roll off" frequency of your front speakers when using the hi-level Neutrik connector. In the manual it says "usually somewhere between 20Hz and 33Hz with most loudspeakers", however, my KEF Q35's do not "roll off until around 45Hz. 3) The slam/depth adjustment is for the LFE input only and does not affect the hi-level input in any way. 4) If you have your front speakers bi-amped then you connect the neutrik connector in the normal way. However, make sure that you connect the sub to the LF speaker terminals on your receiver (which are generally FR & FL anyway) This may help someone.