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 6 (PS 6) utilizes the HC-6 dynamic element also designed for amateur radio use. The -3dB points are fixed at 100 Hz and 12 kHz with a sensitivity of -57 dB at 600 Ohms output impedance (centered at 1 kHz) The Pro Set 6 requires an additional adapter cable.