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Join Date: Oct 2004
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Just wondering if anyone has found any decent discussion or articles regarding this setting. Or if anyone can relate their specific personal experience when experimenting with this setting.
The usual recommendation for this setting is to set it to 120Hz as the LFE channel can contain info as high as that, but that if this creates any subwoofer localization issues, it can be lowered. Interestingly, though, if I am not mistaken, ONKYO, one of the first manufacturers to include this setting, defaults it to 80Hz. Also, if I am not mistaken, it is my understanding that Audyssey (or the like) does not alter this setting and that it is intended to be set manually.
I'm wondering if, maybe, the setting might address cancellation/phase issues between the LFE channel and the main channels when there is some overlap there and similar or identical content is encoded in both places. In other words, with the typical 80Hz main channel low-pass and an LFE low-pass of 120Hz, there would be an overlap between the sub's and the main speakers' output from 80Hz to 120Hz. Because of the different distances of the speakers relative to the sub, and because of the room's very different acoustic affect upon each speaker and the sub, the relative phasing of each speaker and the sub is in many cases different. If similar or identical material is encoded in both the LFE channel and the main channel(s) somewhere in this 80Hz to 120Hz range, there is a potential for some cancellation to occur.
Most receivers in the past could not separately low-pass the LFE channel and it was usually truncated at the receiver's crossover setting. Because the 80Hz crossover was so ubiquitously used (ala THX), and because the LFE channel (supposedly) has a digital brick-wall at 120Hz (as opposed to a roll-off), most engineers (supposedly) begin rolling off the LFE channel around 80Hz, anyway. So, I do not know how much of an issue this may be. But I have yet to see a definitive explanation (surprise) of this setting's use from any of the manufacturers who are obviously including this option for a reason. So, I wonder if there is more to this setting than meets the "ear".
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