Thursday, May 16, 2019

Tips on using reverb for Mixing/Recording from Audiobus forum

Source:  Audiobus forum thread

Here is an excerpt from a guide I wrote for this studios blog
The farther something is from you, the smaller the difference is between any left or right signals. Image a room 20 meter long room. You are facing the drums. The low tom is on the left, hi hat on the right. If you are at the far end, the angles to your ears may only be a few degrees. If you move the drums to a meter in front of you, they may be at 45 degree angles to your ears, making it much more obvious which is to the left and right.
So anything intended to be far away should be panned more to the center. Close items can be panned anywhere, those are just perceived as being to your left or right.
Imagine again you are in the back of a room, a singer is in the middle. When they sing, the sound of their voice will go straight to your head. That is the ‘dry’ signal. Their voice is also radiating in multiple directions, off the walls, the ceiling, and the bass player’s vinyl pants.
The pre-delay parameter adjusts the delay between the dry signal hitting you and the wall or ceiling reflections. If the singer is farther back in the room, some of the reflections would hit you much closer in time to the dry signal. If a guitar amp intended to be at the far wall, you might use a pre-delay of near zero.
If you are trying to match overdubs or a specific hypothetical room, note that three milliseconds is about 1 meter.
Reverb Mix or Wet/Dry- Far away sources tend to have more reverb overall. There is more opportunity for more reflections on the way from the source to you. In some scenarios it can even mask the dry signal - remember the way it sounded when you locked your accordion player in the basement? Raise the reverb mix to move items farther away.
Equalization or Damping- High frequencies get absorbed more easily than low frequencies. So things that are farther away will have a high frequency cut or added dampening. It is difficult to give a default starting point here. I may use anything from 1000Hz to 6000Hz, but that is as much subjective taste as near-far positioning as different surfaces absorb frequencies at different rates.
At the other end of the frequency spectrum, you tend to have a tighter window of what is cut. A roll off up to 200Hz is not unusual.
Decay Time or Room Size - Things will tend to be perceived as farther away if the virtual room is larger. This one is more obvious, but note that if you are trying to ‘glue’ your mix, having a long decay on some tracks and a short one on another will sound unnatural. A slight variation though just makes the room sound irregularly shaped. Remembering regarding pre-delay that three milliseconds is about a meter, note that big concert halls may have just 2 seconds of decay.

@Max23 said:
panning and reverb in this context are a little tricky because most reverbs are not true stereo and or the aux send is mono ...
so you most likely get a sound panned to a side with a reverb that just sits in the middle - but the reflections are supposed to come from the other side ...
Good points. Good things to check. My comments I should note are in the context, I dont mix on iOS. Ive never seen a mono send in a desktop DAW, but yes that would be an issue for the near verb. I often have almost no pan on the far anyway. A true stero reverb helps, but as long as things are panned, it just sounds like a very regular room, you still get a sense of depth.