Good post Jack. Keep in mind that that article was written over 5 years ago and processors have come a long way. Most recent AVRs that I know of include the full LFE. Even the article acknowledged it,
"...low-pass a copy of each main channel at the various frequencies I want and sum that with the full LFE channel?". Possible, yes, and if fact there are some SSP models which do this, but at a price: doing so inherently results in frequency response aberrations due to phase issues."
Autoboy, unless you have an older receiver/processor you should be OK.
And even with an older receiver there are often greater benefits depending on the speaker and room from crossing below if you have capable speakers. I still adhere to the principle that best results are usually obtained by crossing at 1/2 octave above where the speaker output is -3db because of the slope of the filters. Nowadays, I'm seeing more gear with variable slope settings ie 12db, 18db or 24db which allows better blending with the speakers at more crossover points.
The latter part of the quote is what bothers me in that there are people who suggest not only phase issues but intermodulation distortion is introduced in the summation. I have never been able to get a clear answer on that one. At the end of the day I've never detected audible artifacts from the summation so I suppose that is all that matters.
