WHITE VERSION. Radio frequency (RF) interference from cell phones causes buzz pops and squeaks that can ruin a presentation. The ISOMAX 4RF virtually eliminates this interference resulting in high-quality audio for meeting rooms houses of worship and other high-quality sound reinforcement and broadcast applications. Its tightly-controlled pickup pattern and optimized frequency response reduces feedback while preserving voice quality. Its high-pass filter and active vibration isolation system reduce rumble thumps and handling noise and eliminates the need for a separate shock mount.