Technically, we use top-quality driver units from leading suppliers. Air coils and poly capacitors are used in the crossovers and everything is on the brink of being over-engineered.
As measurements typically tell very little about the sound of a drive unit, extensive listening tests are conducted to ensure accurate correlation between data and sound.
Acoustically, we lean towards drive units that are alive and dynamic and we are generally not fooled by those with ruler-flat on-axis response.