Originally Posted by jproy13
I'm going to attempt this and if I'm incorrect, please ppl chime in to correct me,
When using LFE, the receiver will send all the low frequencies to the subwoofer. You will have to set the xover frequency on your receiver to achieve this. So if you set it at 80hz (wich is the recommended setting for use with towers) anything under that 80hz will be handle by the sub. You have to make sure your speakers are set to "small" for this application.
When using "line in" all the low frequencies that would normally go to your L / R, speakers, will be "intercepted" by your sub. You will have to use the xover frequency directly from your sub to achieve this. You have to make sure your speakers are set to "large" for this application. This method although not as popular, tend to have the same effect as not much content under 80ishHz (from a movie soundtrack for instance) would be directed to your surround back and or your center.
this is to the best of my knowledge.
Well, what goes to the sub is dictated by which outputs you use on the AVR and how the AVR is configured, exactly. But, yes, a so-equipped sub's 'LFE input' is for connecting it, conventionally, to an AVR's sub out regardless, though, of the exact bass management scheme being used (i.e LARGE vs. SMALL speakers). With this sort of conventional connection the AVR will send to the sub's unfiltered 'LFE input' a signal that is dictated by how the AVR;s bass management settings are configured. It is up to the user to either configure manually or ensure that his auto-EQ/calibration configures his AVR's bass management settings properly.
And, yes, generally, on a sub that is equipped with both filtered and unfiltered (LFE) inputs, the filtered, line-level inputs would be used to connect it to either the front R/L channel pre-outs of an AVR or pre/pro or to the R/L channel pre-outs of a 2-channel receiver or pre-amp. And, yes, generally, if connected this way to an AVR or pre/pro, the front channels would probably be set to LARGE and the sub's own low-pass filter setting would be used to adjust the sub's output to the front speakers' low-end capability.