Originally Posted by manoharshetty9
how about when all speakers are set to small? does the subwoofer get only the signal below 80Hz or a full signal? am asking cause i need to know if the subwoofer crossover needs to be used to cut off frequencies above 80Hz or accept the full signal with crossover disabled/turned all the way upto 200Hz
When any speakers are Small, and the Subwoofer ON, the Subwoofer gets the full frequency range of the LFE content. (The .1 of 5.1 or 7.1 audio. LFE is essentially gone by 120Hz with almost all of its content below 100Hz.) The Subwoofer ALSO gets bass steered from those speakers that are set to Small in accordance with the 80Hz crossover. The bass that is steered from Small speakers to the subwoofer is removed from the content sent to those Small speakers (i.e., it isn't sent to both). Frequencies which are played in the Small speakers (i.e., above the Crossover) are NOT sent to the subwoofer.
Keep in mind that the Crossover rolls into effect over about an octave (factor of 2 in frequency) so there is a transition region of frequencies where both the sub and any given Small speaker are each playing a portion of that bass frequency for the bass being steered to the sub from that Small speaker. At the beginning of the Crossover, all the output is from the Small speaker, by about an octave lower all the output for that channel is from the Subwoofer. In between, both the Small speaker and the subwoofer each play a portion of the frequency. This is why, for example, it is important that your Subwoofer be set in proper Phase with the main speakers -- so that you don't get cancellation for frequencies where they are both playing the same bass at the same time through the crossover region.
Any speakers that are set to Large get the full frequency range of their content -- none of their bass is steered to the Subwoofer even though other speakers are set to Small.
The general Rule of Thumb is to only do crossover processing in one place at a time. For your question that means that no, you don't have to engage the 80hz crossover built into your sub as well. Either disable the sub's own, internal crossover, or set it to the highest frequency to get it out of the way as much as possible whenever you are using Small speaker settings in the OPPO to engage the OPPO's own crossover processing for bass management.
All of the above only applies to the OPPO's multi-channel Analog outputs. The Crossover and Speaker Small/Large settings have no effect on HDMI audio output for example. (For HDMI audio, make such settings in your AVR instead.)