Have several irs infinity have rebuilt some of the ribbons rewired and changed to electronic crossovers.they are tri amped.that is one amp for woofers ...
The planar drivers in the Infinity IRS systems (IRS 1-V, Beta, Delta, Gamma) were not ribbons. All of the IRS systems were intended to be biamplified and were shipped with electronic crossovers that included an active servo system for the bass. Maintaining the servo is essential to get the bass performance for which these speakers are famous.