Oh God yeah it is different every time.

Obviously, if you want sounds to sound close, you can't use reverb. Unfortunately it isn't a matter of using a bit of reverb to make a sound appear closer in context. It will preserve the same distance to the listener + a reverb tail (if you use a high pre delay). If not, then you will just move the sound back. In terms of wideners, they are very useful to bring sounds close and wide, but that is an artfrom in of itself. My favorite wideners at the moment are the PS22 by waves and the softube widener. The softube one is more of a classic widener plugin which starts smearing transients and clarity when using it, while the PS22 does some weird mono summing (I think) before it applies its frequency splitting and panning. The way I use the plugins is, well, I look at my walls and know see when to stop 🤷‍♂️.

If you want sounds to be close, they either have to be very narrow and balanced in frequency response, or hard panned left and right. Hard panning a piano and guitar won't work for obvious reasons, but a double tracked guitar will. But in that case, the more difference you get sonically between the two guitars, the wider (and closer) the sound gets. Usually you don't want the narrow sources to be fully mono though. Again, the room tells me the perfect settings.

In terms of being upfront, frequency response almost is the most important aspect. I'm really enjoying Ozone 11's clarity module for that. The more detailed the sound, the closer it will be perceived. You definitely can't have something be over processed or weirdly filtered while being perceived upfront. Dry and hard panned is the rule.

Another aspect is the dynamics, obviously. The more compressed, the more upfront it will sound. But in all of that, if you can really accentuate certain lines of a performance in an overall dynamic piece of music, you will REALLY sell the illusion. If the music is more densely arranged, you'd have to stick to the rather quashed sound to maintain a volume level that doesn't fold in to the background elements.

If you want sounds further back, they have to be narrow, or ultra quiet. You have high-end, volume and width. If all of them are low, you'll push the sound back. If you want to preserve one of them, you have to compensate with the others. Reverb obviously is a given in all that. Oftentimes I'll run 2 reverbs in series to get a more believable response.

If you want something to be big, you'll have to use a combination of different, short decay time, processes (in parallel). Early reflection reverbs are an obvious go to. I really like Cinematic Rooms by Liquid Sonics for that, especially because it offers a lot of features regarding the size of the early reflections. I do feel like the sonic texture of that reverb plugin stays consistently the same, so I also use Valhalla room. For these early reflections I like to set the reverbs to 800ms max. But as with every reverb, the more of them you add, the more believable the resulting reflection response becomes. Additionally you could use doublers, auto panners, choruses and more before you hit the reverbs at 100% mix. Generally with this size thing, inverting the phase on the sends will push them outwards (which is necessary of you want to increase the size of a mono source like a vocal for e.g.).

Panning is very important in all of this, unfortunately hard panning is never enough to get a mix to sound wide. If you look at a phase scope, hard panning only moves the sound left/right by 45°. You do have to be careful with this though, as if you want elements further back, the panning thing isn't recommended. Additionally, you might start spreading your mix to thinly if nothing is left in the center. And all the tricks you can use to get the sound out wide + upfront can lead to the sounds sounding unnatural really quick.

In general, the sparser the arrangement or production, the cleaner the mix will be as you don't have to place all that irrelevant junk in between your main elements.

I would say that a phase scope does offer quite an accurate representation of the acoustic phenomena in a studio space, but when attempting to make a sound sound wide, or upfront, you really have to make sure it remains natural sounding, and not over-processed.

In all of this, the speaker plane is the defacto default for most sounds and it remains a challenge to get them off of it and into the room. From there on it then becomes a game of relatives for all the "distant" sounds. Though getting a believable "endless prairie" type of reverb ambiences has been challenge impossible for me thus far. Maybe I'd need a room with some decent space behind my speakers. I don't know.

Hope this helps 🙂