## LAME bitrate and lowpass filters

2

Is there a formula or chart that specifies what lowpass filter LAME will automatically invoke for certain bitrates? I've looked around the net and can't find anything on this.

And is there a specific logic that dictates said formula or chart, besides just listening tests?

1

Deeper source(code): https://github.com/rbrito/lame/blob/origin/libmp3lame/lame.c#L211

Update:

--preset insane seems to be using a lowpass filter as well...
see LAME: Why is a lowpass filter used with --preset insane

1--preset insane seems to be using a lowpass filter as well... see http://sound.stackexchange.com/questions/38109/lame-why-is-a-lowpass-filter-used-with-preset-insane – Tieme – 2016-01-24T15:49:18.193

Since it's been over a year, and this is the first answer, I'm going to mark it as accepted, lest I forget. But I would prefer you add your comment to the answer proper, and would love if you could find anything about WHY they use those particular filters. – trlkly – 2016-01-24T17:39:18.943

No idea, you could check this thread https://hydrogenaud.io/index.php/topic,106868.msg874354.html#msg874354

– Tieme – 2016-01-25T12:43:52.137