We experimented with this after a few people had asked us how to recreate the effect and we found that putting a stereo expander over the whole mix and making it 100% narrow does the job.
There are several free stereo expanders online if you do a search for “free stereo expander”.
What is a stereo expander?
In other words you are turning your stereo (left and right) mix into a single (centred/mono) file.
Hip Hop lends itself to this technique as it produces punchy and hard edged mixes, but this is an ‘effect' and in most instances you would want to use it sparingly.
Another thing to note is that you may have to remix the instrument levels on your track because the stereo expander will change the balance quite dramatically.
Another use for stereo expanders
Something else that is worth mentioning in this article is the use of stereo expanders as a mixing tool. A lot of producers will test their mixes in mono as this highlights problem areas in the mix.
If you have a mixed song, take a listen to it with a stereo expander set to 100% mono (narrow) and notice how some instruments seem way too loud and others are lost.
The instruments that are lost may be smothered by competing frequencies within your mix. EQ is vital to a good mix, so when you set your track to mono you are effectively putting everything on top of each other. The only way to clarify the individual parts is to fix EQ issues and volume. There are no hiding places in a mono mix.
Once you have sorted the mix in mono you can switch back to stereo and see how clear your mixes are!