Question Yamaha dsp ax759se setting

I’m just wondering what the point of the lfe effect setting is for, now I’ve set the crossover but can’t find any info for this I can choose headphones or speakers it goes between 0 and -20. I’ve added a copy of the page from the instruction book. Just looking for an explanation thanks people.

 

Found it, it’s for adjusting dts and dd as some lfe can’t be reproduced