What have I done wrong with my reverse Durso?

[craigils]

I attempted to implement a reverse durso on my sump today, but it didn't do much to improve the noise.
I have attached a picture and video of it (which shows the noise as well)

To be honest, I don't fully even understand the theory behind a reverse durso, so my attempt was pretty much just shooting in the dark.

Does anyone know what's wrong? For one, I'm still getting quite a bit of bubbles coming out. But I'm not convinced that the bubbles are even the cause of the sound.
It just sounds like gushing water. Should I add a few more bends before the water reaches the bottom? Or perhaps lengthen drain pipe so that the durso is deeper into the water?

 

[Saltyreef]

The main issue is the single drain.
Most of these silencers dont work on everyones application. Its hit and miss, ive used a few different designs.
My lifereef silencer only removed a little bit of the gurgling sound from my single drain.
Can still hear it from the other side of the house.