Nearly every mix uses reverb in some way. It can create artificial spaces, make thin tracks sound fuller, and create depth and dimension. However, it can also turn your tracks or entire mix to mush if you’re not careful. But what if you’re being careful with the reverb level, but even a tiny bit of ‘verb seems to muddy things up?
In these cases, you just might find that a high-pass filter is just what the (mix) doctor ordered. Some reverbs even include their own high-pass (sometimes called a low-cut) filter for just this purpose. High-pass filters attenuate the lower frequencies of a signal, only letting the higher frequencies pass. Since the lower frequencies tend to be the ones that bring the mud, filtering out those low frequencies before they hit the reverb can keep your reverb from washing out your tracks. Experiment by putting a high-pass filter on your reverb with a the cutoff frequency set low (say 50 Hz) and then start raising the cutoff frequency until you notice the mush vanish and only your shimmery ‘verb remaining.