The earpieces are full-sized, with heavily-stuffed cushions for operator comfort during long operating stints. The ear pad covers are removable, for washing, and replacement pads are also available. The Pro Set features Heil Sound’s exclusive phase reversal technology, which allows the user to “move” the incoming signal by engaging the phase-reversal switch; this creates a unique spatial widening sound that can, in some situations, significantly improve copy in a tough DX pile-up.
The speakers in the Pro Set Series are 200 Ohm nominal devices, with a -3 dB point at 8000 Hz. This combination reduces hiss found in receiver audio stages. These speakers exhibit medium sensitivity but are easily driven by most rigs by turning the AF Gain control up to about 2 o’clock.
The Pro Set IC (PS IC) utilizes the Heil Sound IC electret element. This element has been made to utilize bias power in ICOM radios which addresses low-gain issues that arise when using dynamic elements. The -3 dB points are fixed at 80 Hz and 12.5 kHz. The IC element requires +5 volts DC bias power, which all ICOM rigs provide. The PS IC is shipped with the AD-1 IC adapter cable. The IC adapters have no internal DC blocking capacitor so bias voltage can be passed allowing the IC electret element to operate.
Each Pro Set is equipped with a windscreen for the microphone. The windscreen does not affect the frequency response of the microphone, and it is highly effective in minimizing breath blasts while you’re speaking.