Compound quarter-wave loading runs multiple tuned acoustic resonator paths inside one enclosure. Each path has its own length and its own tuning, and their outputs combine at the mouth. The geometry lends itself to a forward-biased cardioid pattern, providing some passive rear rejection.

Acoustic loading carries much of the output, so a Paraflex enclosure clears 100 dB sensitivity and reaches its target SPL on a small share of the amplifier power. Everything downstream of that follows: lower distortion, cooler voice coils, and headroom still in hand when the system is working hard.

HOQS designs its own drivers because Paraflex loading is hard on the drivers. The enclosure holds the cone under sustained acoustic pressure that restricts its motion, and that pressure is typically uneven across the cone’s surface. An off-the-shelf driver isn’t engineered for the constraints Paraflex imposes, leading to higher distortion or even mechanical damage. HOQS is the only company that builds drivers specifically for Paraflex, designed to minimize distortion, resist long-term compression, and achieve the maximum output from your Paraflex enclosure.

Cone stiffness

High acoustic loading and uneven loading flex a paper cone. HOQS drivers typically use carbon fiber so the cone moves as a piston instead of deforming under pressure. This also makes HOQS drivers well suited for traditional folded horns with higher compression ratios.

Compliance and motor strength

Softer suspension paired with high grade magnets lets the cone move freely at high compression ratios while keeping its motion fast and accurate, lowering distortion and raising output through the pass band.

Thermal design

We continually improve the thermal handling of our driver by employing the latest coil coatings, adequate venting, and optimizing the magnet gap to transfer heat away from the coil.