[Mr.T]

"Walt" wrote in message
...

.5(R-L) + .775(L+R) = 1.75(R) + .275(L)

Since he is first doing a difference of L and R, that can be .5(R-L)
*or* .5(L-R)

Well, he says he "invert[s] the phase left channel", so I'll take him at
his word. That's the only place he say he (intentionally) inverts
polarity.

You are disregarding the original phase relationships. Consider the formula
for negative R, or negative L, and everything in between.

What's unclear is what he means by "decrease the loudness of both
channels by 77.5%" before summing to mono - I wrote that as .775(L+R)
when it may well be .225(L+R)

That would give:

.5(R-L) + .225(L+R) = .725(R) - .275(L)

Why anybody would want to do this is beyond me.

Agreed.

MrT.