Solved Muffled sound

I'm trying to create a muffled sound like I'm hearing a clip from the other side of a closed door.

Does anyone know what effect would I use to create that?

Hard to advise for sure without hearing the actual clip but generally you would be wanting to remove the higher frequencies and probably allso removing or taming some of the mid tones. A low pass filter would be a good place to start if you had one but maybe try the Parametric EQ starting with:

• Filter Style - High Frequency Shelf (this filter will cut the volume of all frequencies above the Cutoff Frequency)
• Cutoff Frequency - 300Hz
• Transition width - 1.0 oct (determines how quickly the frequencies above the cutoff drop to the desired level)
• Amount - minus 45dB (determines how much higher frequencies will be cut)
• Output gain - start at 0dB and reduce if required (determines the volume of the frequencies below the cutoff)

.
Play around with the parameters, particularly the Cutoff Freequency and the Amount slider, and see if you can find the sound your looking for.

Cheers, Robbie