Tubeless In-Ear Audio (tia) is a patented IEM design methodology that aims to reduce unwanted resonance and distortion for a transparent and lifelike sound signature. The tia system is comprised of three major elements: open balanced armature tia drivers, the tia single-bore design, and tia acoustic chambers. U18s features two major elements of the tia system: the tia driver and the tia single-bore design.

Air Pressure Exchange (Apex) is a patented vent that releases air pressure in a sealed ear canal all while retaining standard IEM levels of isolation; enabling musicians and music enthusiasts to listen more comfortably for longer. This venting alleviates listener fatigue and allows for a much more realistic soundstage. Apex comes in three module variations for U18s: mX, m15 and m20

Linear Impedance Design (LID) is a patented circuit that corrects the non-linear electrical resistance of the multiple driver-sets comprising this 18 driver IEM. Varying source amplifier output impedance in devices like smartphones, body packs, DAC/amps, and DAPs typically results in varying frequency response across them, depending on the increase in resistance. Restoring proper interaction with the source and preserving the desired sound signature enables a consistent reliable sound.

The electrical low pass filter lowers distortion by eliminating unwanted frequencies. It does this with an electrical circuit that eliminates target frequencies before they reach the driver. An acoustic damper (old technology) doesn’t actually prevent frequencies from getting to the driver, it merely blocks frequencies from getting to the ear. At higher volumes acoustic dampers can introduce unwanted distortion through vibration and air movement.