[Hasan Aydin]

I have a question about the LFE channel in 5.1 mixes. I am currently using headphones with the VIRTUSOSO Binaural software and will buy a 5.1 system with room correction and phase alignment for the LFE channel in the future.

Now I have noticed that with some movies there are phase cancellations when I activate/deactivate the 120 Hz LFE low pass filter in VIRTUOSO. Is it best to turn this on or off during mixing?

And when mixing music or movies in 5.1, should I add a sharp low pass filter at 120 Hz (42db/oct) or a more gentle one at another frequency in my LFE Channel?
I use the LOWENDER plugin for the LFE channel and set the Plugin internal Lowpass Filter to around 1 kHz and then use a separate EQ at 120 Hz as I can control the slope and Frequency more precisely.

I want to avoid phase cancellations when the mixes are played back on other surround systems. And most AVR receivers also have a low pass filter in the LFE channel, so I don’t know how to handle this when I am mixing on my monitoring system.

What would be good practice in an ideal world?

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“I know that I know nothing”

[Phil Koenig]

Extreme filter slope in your LFE filter will cause extreme phase shifts; every process has a cost…

 

I suggest using a less extreme filter slope, maybe 6 or 12 dB/octave.

[Hasan Aydin]

Thanks Phil, still at 120hz or should I go lower?

and I read somewhere in a Dolby document that a 120 Hz (42db/oct) filter is recommended. Now I am a bit confused.

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“I know that I know nothing”

[Phil Koenig]

It depends on your equipment, your room and your ears.