Frequency and Impulse Response

The A/D converters of the AVB Tool are optimized for extremely low latencies (Short Delay IIR filters). At single speed, the conversion prioritizes frequency response to ensure linear conversion across the entire frequency band.

At double and quad speed (88.2 kHz and higher), the conversion has been optimized to deliver a near-perfect impulse response. This is achieved by allowing a lower cutoff frequency and a slower roll-off of the anti-aliasing filter. It shifts from around 44 kHz to 25 kHz at 96 kHz (84 kHz to 32 kHz at 192 kHz) and attenuates higher signals less steeply. The resulting impulse response shows significantly less ringing artifacts than steep filters at at a higher cutoff frequency. Since even the lower cutoff frequencies are located well above the audible range, the advantage of the improved impulse response outweighs the benefit of a higher cutoff frequency.

If the AVB Tool is used for scientific research (ultrasonic signals) with measurement microphones that maintain a linear frequency response above 25 kHz, please contact your support for a solution.