Audio Input Section¶

Modular Input Structure on Edge and Radius AEC¶

Symetrix Edge has 4 configurable card slots and Radius AEC has 1 configurable card slot, which can be configured with any combination of input or output card. Please see the instructions for Symetrix I/O card Removal and Replacement.

Analog Audio Inputs. The analog audio input signals are connected via detachable, balanced Euro-block connectors. The analog input section accommodates microphone, or line level signals with nominal levels of -50dBu, -40dBu, -20dBu, or +4dBu. By default, headroom is 20dB, meaning for example, that with a +4dBu reference level, signals up to +24dBu can be passed without clipping. +48V phantom power is available on each input.

Following the initial input stage, there is a digitally controlled volume control circuit that provides gain in 0.5dB steps. This is used to fine-tune the input signal level if it doesn't exactly match the dB steps provided. For example; the +4dBu, or -10dBV reference level selections may not provide the exact input gain level that you may need for a line level source. Furthermore, the user may use this chip to increase or decrease headroom. For example, if an input signal doesn't have much dynamic range, a gain could be applied so that the signal applied to the ADC is closer to 0dBFS. This arrangement allows the user flexibility in constructing the optimum gain staging for their application. The goal of the analog input section provides the analog to digital converter (ADC) with a signal that is as "hot" as possible without ever clipping.

Digital Audio Inputs. The digital audio input signals are connected via detachable, 3-conductor Euroblock connectors. The Digital Inputs will accept an AES (Audio Engineering Society) 3-conductor stereo input, or S/PDIF (Sony/Phillips Digital Interconnect Format), 2-conductor stereo input. Digital playback equipment can be connected to these inputs in which case the audio signal path stays cleanly digital through out the DSP until arriving at the Analog Output D/A converter.

AEC Inputs. The EDGE or Radius AEC provide the option for the installation of a 4 channel Acoustic Echo Cancelling card. The installation of the Symetrix AEC Card will bring with it the AEC input module into the software configuration once the hardware is synced to the design. The advanced AEC algorithm that Symetrix uses in the Edge unit will take the audio which is fed into the reference and remove that program material (echo) from that which is picked up by the AEC microphone input on this card.

Fixed Input Structure on Radius¶

Symetrix Radius DSP has 12 fixed analog audio inputs connected via detachable, balanced Euro-block connectors. The analog input section accommodates microphone, or line level signals with nominal levels of -50dBu, -40dBu, -20dBu, -10dBV, or +4dBu. By default headroom is 20dB, meaning for example, that with a +4dBu reference level, signals up to +24dBu can be passed without clipping. +48vDC phantom power is available on each input.

Following the initial input stage, there is a digitally controlled volume control circuit that provides gain in 0.5dB steps. This is used to fine-tune the input signal level if it doesn't exactly match the dB steps provided. For example; the +4dBu, or -10dBV reference level selections may not provide the exact input gain level that you may need for a line level source. Furthermore, the user may use this to increase or decrease headroom. For example, if an input signal doesn't have much dynamic range, a gain could be applied so that the signal applied to the ADC is closer to 0dBFS. This arrangement allows the user flexibility in constructing the optimum gain staging for their application. The goal of the analog input section provides the analog to digital converter (ADC) with a signal that is as "hot" as possible without ever clipping.