2.0 downmix from strange anime audio configurations

tormento · 7th May 2025, 18:17

I hate when anime have strange audio configurations.

I have found 2.1 (L+R+LFE) and 3.1 (L+C+R+LFE) utterly annoying because there are only a few formats that can support them.

The easy way would be to use ffmpeg with -ac 2 but I am almost sure that there are better formulas out there.

I just can't find them

Any help is welcome.

hellgauss · 8th May 2025, 06:10

Try something like

ffmpeg -i "input.wav" ... -ac 2 -rmvol 1.000 -center_mix_level 0.707 -lfe_mix_level 0.0 ... "out.wav"

Those numbers are default values (lfe is discarded). You can rise/lower center_mix and lfe_mix as you desire. Note that with rmvol=1 the volume is scaled in order to ensure no overflow possibility, so you have to tune -rmvol to get the desired volume.

tormento · 8th May 2025, 10:25

Quote:

Originally Posted by hellgauss

Try something like

Thank you!

What are good values for LFE? I've read that it can damage loudspeakers when fed directly but I believe it's FUD.

hellgauss · 8th May 2025, 11:23

If you have good speakers try 0.3 and then tune, otherwise something less.

I do not think a wav file can damage, perhaps the speaker will not play those frequencies, but I'm not expert. The standard however is zero.

Sunspark · 8th May 2025, 17:36

I have a 2.1 system so I keep the LFE. If I had a 2.0 system, I would probably drop it though. It's relative though, if you have giant room-size speakers from the 70s then it's fine. If you have a headset, then it's not worth it.

My downmix settings for LAV for my 2.1 system, Output speaker config: Stereo, center: 1.0, surround: 0.71, LFE: 1.58, Clipping protection: Off, Normalize matrix: Off, Matrix: None.

7th May 2025, 18:17	#1 \| Link
tormento Acid fr0g Join Date: May 2002 Location: Italy Posts: 2,944	2.0 downmix from strange anime audio configurations I hate when anime have strange audio configurations. I have found 2.1 (L+R+LFE) and 3.1 (L+C+R+LFE) utterly annoying because there are only a few formats that can support them. The easy way would be to use ffmpeg with -ac 2 but I am almost sure that there are better formulas out there. I just can't find them Any help is welcome. __________________ @turment on Telegram

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8th May 2025, 06:10	#2 \| Link
hellgauss Registered User Join Date: Sep 2002 Location: Italy Posts: 146	Try something like ffmpeg -i "input.wav" ... -ac 2 -rmvol 1.000 -center_mix_level 0.707 -lfe_mix_level 0.0 ... "out.wav" Those numbers are default values (lfe is discarded). You can rise/lower center_mix and lfe_mix as you desire. Note that with rmvol=1 the volume is scaled in order to ensure no overflow possibility, so you have to tune -rmvol to get the desired volume.

8th May 2025, 11:23	#4 \| Link
hellgauss Registered User Join Date: Sep 2002 Location: Italy Posts: 146	If you have good speakers try 0.3 and then tune, otherwise something less. I do not think a wav file can damage, perhaps the speaker will not play those frequencies, but I'm not expert. The standard however is zero.

8th May 2025, 17:36	#5 \| Link
Sunspark Registered User Join Date: Nov 2015 Posts: 633	I have a 2.1 system so I keep the LFE. If I had a 2.0 system, I would probably drop it though. It's relative though, if you have giant room-size speakers from the 70s then it's fine. If you have a headset, then it's not worth it. My downmix settings for LAV for my 2.1 system, Output speaker config: Stereo, center: 1.0, surround: 0.71, LFE: 1.58, Clipping protection: Off, Normalize matrix: Off, Matrix: None.