Err… stereo reverb diffuses the stereo field intentionally, this makes a mono sound “wider” but if your sound gets its stereo sense from things like inverse phases (e.g. the mono sum is weak) you could get a narrowing effect compared to the source via this diffusion, because the source is depending on the cancellation of cross-channel components to widen the stereo field. Because it’s diffuse, you’re not likely to regain such a strong sense of stereo imaging after the reverb to make it wider again easily. One way to look at addressing the problem is to consider running the Space (or any reverb, this isn’t unique to the Space, by the way) as two independent parallel mono channels, which will prevent any cross-channel diffusion from occurring in the algos. This might work well, or the resulting phase mangling of the reverb itself may again diffuse some of the phase-cancelling stereo width.
The other option is to NOT widen before the reverb, but instead apply whatever you’re already doing to create a wide stereo field afterwards. This lets the reverb diffuse all the common mode things and can make normal stereo tricks with phase more effective aftewards, since the counter-phase elements are not themselves diffused into the reverb. It may also keep the natural reverb sound wider too, depending on the actual content.
So, to summarize:
- Try running the Space in dual-mono, not stereo.
- Try not doing your stereo sweetening tricks before the Space, and see if the Space can widen the coherent source enough (you’re avoiding fighting the algos, in this case)
- If you’ve done 2 and it’s not enough, try adding a stereo trick after the Space (this can be any of the ones already mentioned, or a simple chorus pedal, or just inverting the phase of one channel, it really depends on the harmonic content and the resulting phase relationships that come out of the reverb algo).
Some algos blur the sound too much to really make for a wide stereo image anyway, so you might put some serious work into tweaking the algos that do give you the best image first, before throwing more gear at the problem, too.
Psychologically, stereo imaging works based on both left-right time difference and left-right phase different (which are basically the same thing, just on different scales). Delays of under some tens of ms “feel” wider because we associate those delays with the slapback of real spaces which hit our ears differently in time. Phase differences feel wider because they trick our ears into feeling like the source is not coming from the same point in space by psychoacoustically decoupling the two channels. Sharp, clear differences in left and right in both cases feel more strongly “stereo”, and reverb by definition blurs these signals by, in a sense, creating a whole lot of them at smaller intervals of time and phase. Depending on which frequencies are present in the source and which are most blurred by the reverb, you can get a significant difference in the apparent “width” of the individual algos. So in summary, if you’re going for a very specific 'verb sound, it might be difficult or impossible to get as wide of a stereo image for a given source as you like - there may be a compromise between the depth and intensity of the 'verb and the stereo width that you’ll need to tradeoff anyway. It’s not always the case, and it’s highly dependent on the source and algo settings, but just know that what you’re trying to do is in some ways at odds with each other.
