How do i make this effect

ok, so i play a game where the music in it is effected to a noticeable degree and i already know how to do every effect except one in particular that’s really starting bug me. Here’s a link to an example, https://www.youtube.com/watch?v=H5IPoi7zopk - at about 00:52 there’s what appears to be a combination of a bit crusher and some kind of gradual/gain filter. I know how to do a bit crusher effect, but how do you warp it and make sound like that? (If that’s even possible that is…)

Phasing? You can get that effect by making a copy of the sound (main and copy one above the other) and change the speed of one very slightly. As they play, bands and groups of tones will add and cancel giving that wooshing through a tunnel sound.

You may have to mess with Amplify to keep from overloading since you’ll have two copies the sound running at the same time and adding.

You might also have to produce the effect as a separate show and add it to the main show later. Drums turn to mush when you try that.

In the Paleolithic Era, the DJ would get that effect by playing two copies of the same vinyl title and changing the speed of one very slightly. Or drag his finger on one. The 1200 series turntables had that huge speed slider on the right to make matching and phasing easier.

Koz

I think the “gradual” thing is an automated high*-pass [HP] filter which sweeps from 1KHz to 0 in two seconds.
There are free VST plugins which do that, e.g … https://youtu.be/tNhb3N9U4dM?t=1m27s

[ * Audacity’s built-in Wah-Wah effect is similar, but it’s a Low-Pass [LP] effect ].