velodyne DD hook up

I have a relatively new DD-15 and use the XLR input from the XLR output from my pre/pro (Anthem D1) for music and HT. I don't know why the other poster said you can't use the XLR input as the manual says you can.

At this point I have an XLR Y that I will use to run my pre-output to the XLR input.

As I mentioned, the DD has one XLR input for mono LFE. With a 2CH preamp that has a pair of auxillary XLR outputs that are internally buffered from main outputs, an XLR Y-connector could be used between the preamp's auxillary outputs to bridge L & R channels for XLR input to sub. However, this will not work with the many 2CH preamps that wire auxillary outputs in parallel with main outputs. In those cases you must run both channels across via RCA inputs to take advantage of the sub's ability to combine them into mono while buffering L from R with respect to the preamp.

A surround-sound pre/pro/receiver is a very different animal, insofar as the LFE output internally bridges and buffers L & R, applies a fixed crossover frequency & rolloff, and may EQ the sub signal in accordance with THX, etc. Since using LFE implies that a fixed crossover point has already been applied to the signal upstream by pre/pro/receiver, I'm curious whether using XLR input into DD disengages the ability to manipulate crossover point & rolloff within the DD's systems menu. This would be undesireable in a 2CH application.