In a JRiver thread there was a discussion about JRiver's BM formulas, for example - L^2 + R^2 + C^2 + SR^2 + SL^2 = LFE^2, from a post by Matt, JRiver's CTO):
The thread continued long and strong about requirements for +10dB LFE attenuation and other important considerations like slopes, headroom, etc.
At the moment, I can't seem to gain confidence in knowing the bottom line conclusion for the correct implementation of BM for 2.0, 5.1 and 7.1 contents.
Focusing for starters on summing formula for 2.0 to 2.1 with Stereo music, looking at this simple formula (taken from EqualizerAPO boards) -
SUB=0.5*L+0.5*R
Is this correct?
What if there is uneven bass content (it is Stereo music) in the L+R channels below the Low Pass Filter highest audible frequency?
As a background and context, this is my overall goal -
Integrating a subwoofer with the main speakers while keeping everything in the digital software domain for flexibility and proper integration with other software tools like Dirac Live.
I am currently playing with the highly flexible EqualizerAPO (together with VoiceMeeter in order to bypass the OS Mixer when possible) and while I feel fairly confident with it I do need help with the formulas for different content formats.
5.0 source, redirecting bass to the 0.1 channel (assume 0.1 channel is silent for now) should use this equation:
L^2 + R^2 + C^2 + SR^2 + SL^2 = LFE^2
Assuming values from 0 to 1.0, the maximum LFE is then Sqrt(5) or 2.24. This means to avoid clipping, all values must be multiplied by (1 / 2.24) or 0.45.
So, in AlexB's example of a single channel with full intensity sound:
L^2 + R^2 + C^2 + SR^2 + SL^2 = LFE^2
1.0^2 + 0^2 + 0^2 + 0^2 + 0^2 = LFE^2
1 = LFE^2
LFE = 1
Then, to adjust for attenuation:
LFE = 1 * 0.45 = 0.45.
The thread continued long and strong about requirements for +10dB LFE attenuation and other important considerations like slopes, headroom, etc.
At the moment, I can't seem to gain confidence in knowing the bottom line conclusion for the correct implementation of BM for 2.0, 5.1 and 7.1 contents.
Focusing for starters on summing formula for 2.0 to 2.1 with Stereo music, looking at this simple formula (taken from EqualizerAPO boards) -
SUB=0.5*L+0.5*R
Is this correct?
What if there is uneven bass content (it is Stereo music) in the L+R channels below the Low Pass Filter highest audible frequency?
As a background and context, this is my overall goal -
Integrating a subwoofer with the main speakers while keeping everything in the digital software domain for flexibility and proper integration with other software tools like Dirac Live.
I am currently playing with the highly flexible EqualizerAPO (together with VoiceMeeter in order to bypass the OS Mixer when possible) and while I feel fairly confident with it I do need help with the formulas for different content formats.
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