Spiritia is based in the concept of wave motion. All living things produce energy, different types of energy have different attributes. Anima spirtia has the virtue of being a perpetual form that not only renews itself, but renews energy in other beings it touches.
The EVIL series are biological representations of the mechanical technology that the Protoculture already engineered. We now know that said technology was based on a naturally occuring biological manifestation, i.e. the Vajra. Fold technology, barrier shields, and reaction cannons were all biologically recreated in the EVIL series, and later on a mass-producton scale with whatever the AFOS was. This isn't a concept exclusive to Macross, other sci-fi & anime has touched on bio-mecha for years, both before and after. Take a look at Farscape, a fairly popular sci-fi series, and one which was based highly in bio-technology. The Vorlons & Shadows in Babylon 5 being the higher species of that universe also used bio-technology. Even the recent BSG adopted the concept that bio beats mechanical in the technological hierarchy.
What the Sound Energy Converter/boosters do is convert that bio-energy for mechanical use and amplify it into the beams shown. We also know now that this ability was likely based in Vajra technology as the Vajra have a working bio-internet that's fully compatable with protoculture/human based mechanical counterparts. Hell, we even see this in Macross Plus with the BDI/BCS interface both used for the YF-21 & connection Myung with Sharon. Coincidence that ti required a bio-neural chip to make Sharon self aware?
Cry space monsters & magic all you want, but the fictional tech base is there, deal with it.
Also, super robot shows are distinguished by bright colored robots, they're distinguished by hot-blood completely replacing pilot skill, and of course ywlling out attacks replacing any need to control a robot. This is not true for Macross 7, as even the guitar controls are just an alternate interface for a standard flight control scheme, and still require piloting skill to use.