The Tesira SAC-4 is a modular analog input card for use with Tesira SERVER or SERVER-IO devices. Each SAC-4 provides 4 channels of mic or line level audio input with Ambient Noise Compensation. The inputs are electrically balanced and provided on plug-in barrier strip connectors. The card features a new Biamp algorithm, AmbientSense™, which intelligently distinguishes ambient noise from program material or announcements, thus greatly improving processing performance over traditional ambient noise compensation. Software control is separated into separate blocks for mic/line inputs and ANC processing. This allows the system designer to use the inputs independent of the ANC processing, and apply the ANC algorithm to inputs from a different part of the system. Software configuration and control for each input shall include gain with clip indicator, phantom power on/off, mute, level, and signal invert. The ambient noise compensation algorithm shall be configured and controlled separately in software.