When dealing with true surround source material, the choice of configu- ration is simple--choose the 4-in or 5-in version. The algorithms are all designed to treat the inputs uniquely. If the algorithm is a reverberator or room, then each input will propagate into the space from the direction of its virtual source. If the algorithm is a delay or effect, each input will be treated by itself, and then possibly propagated into shared feedback paths.
But when dealing with stereo source material (the more typical case), some thought must be given to the choice of configuration. The 4-in or 5-in con- figuration may still be used of course, and the source material will be more obviously placed in the front of the virtual space. In the case of a delay or effects algorithm, not all voices will be activated. When the 2-in/multi-out configuration is chosen, the input signals are also propagated to the surround inputs (post level, post pan). This will sound different. A reverb may sound more full. It will still be surround of course, but will not maintain the same frontward localization. Delay and effects algorithms will now have all voices activated and may be considerably more complex. There may be a small dif- ference in gain for the same presets in the 2-in or multi-in configuration.
There’s no right or wrong in this choice. It’s up to the user which of these configurations to use. But it is important to know how the sound will change based on this choice.
All the DSP configurations are described below.
Single Stereo (Mono In)
A mono signal is split into a stereo signal.
Single Stereo
The left and right inputs are sent through a single virtual machine.
Dual Stereo (Mono In)
The left signal travels through one virtual machine, and the right signal travels through a separate second virtual machine.
Dual Stereo
Two stereo signals are processed independently by two virtual machines.
