Example Reverb on Guitar and Put it Behind Singer

1) Simply Reduce Pre Delay so the Guitar Part Almost in the Room

• i.e. in Either Case the Element that Should Appear Further Away (i.e. e.g. in the 3rd Speaker Behind the Phantom Mid) Needs Less Pre Delay

2) Also Reduce High Frequencies of Reverb to Simulate a Further Away Guitar 

3) Also Think About Putting the Guitar Reverb Opposite of the Guitar Itself and Use Reverb in Mono

4) Add the Same Delay as Vocal After the Reverb