Question 1

How is this different from turning the bass up in a player EQ?

Accepted Answer

A playback EQ only exists on the device doing the playing. Move the file elsewhere and it sounds exactly as it did; hand it to someone and none of it comes along. This writes a new file, so the change is in the audio itself. A playback EQ also puts every decibel you add straight onto the output level, which is why loud tracks distort when you boost them — here the result is levelled to −14 LUFS and only the peaks that poke over are caught by a limiter.

Question 2

It does not sound any bassier on my phone.

Accepted Answer

A phone speaker cannot reproduce the fundamentals — roughly 40–80 Hz — at all, so lifting that region only adds energy it will never move air with. This shelf reaches a little above 110 Hz, so small speakers do pick up some extra body, but not the deep bass itself. To check the difference, compare on earphones or a speaker that actually reaches low.

Question 3

Can I run this on a separated bass stem?

Accepted Answer

Only if the stem is the end product. If you plan to mix it back with the other parts, do not: the chain ends in a limiter and a level match to −14 LUFS, and those belong to a finished track rather than to one part of one. Applying them per stem changes what the sum comes out at. Mix the stems untouched, then bring the mixed file here.

Bring out the bass

Mastering

Equalizer