Bass Management Summing Formulas

[ronkuper]

Hi guys,

I saw different recommendations for BM channel summing (XO after the summing) and I wanted to discuss correctness, compromises, and considerations.


For example for 2 channels to 2.1:

SUB=0.5R+0.5L

Others have mentioned:

SUB=(0.707946 x L) + (0.707946 x R)

Which is correct?
Also, what if there is uneven stereo content in the bass frequencies?

For 5.1 to use with bass management:
Matt (JRiver's CTO) mentioned this formula -

 L^2 + R^2 + C^2 + SR^2 + SL^2 = LFE^2

(Then add the original LFE channel)

An interesting discussion which forms the internals of JRiver's Bass Management - Bass Management Testing


What do you think?

 

[MAAC0]

If You have two fullrange speakers You get 1Bass+1Bass, So I would sum 1+1, but would add some highpass filtering to the sattellites.