Sound Devices, LLC - Portable, Professional Audio

Many test and measurement applications take advantage of the impressive bandwidth offered by the 722 and 744T analog inputs. Linear frequency response, particularly low frequency response, is needed for noise and vibration measurements. Linear high frequency response is useful when slowing audio in post production.

High Frequencies

Below is the frequency response of the 744T microphone preamplifier with the following test conditions:

• 50 dB of gain
• 150 ohm load on the input
• sampling rate of 192 kHz

Note that the vertical scale is in 0.5 dB increments. At 40 kHz, the preamplifier is 0.2 dB down; at 80 kHz the preamp is down 1.1 dB. Please note that the end of the graph does NOT show 80 kHz

Low Frequencies

These tests were performed on a Prism dScope because of its measurement linearity below 10 Hz. Below is the frequency response of the 744T microphone preamplifier with the following test conditions:

• 50 dB of gain
• 150 ohm load on the input
• sampling rate of 96 kHz

Note that the vertical scale is in 0.5 dB increments. The low frequency response is down 0.2 dB at 10 Hz, 1 dB at 5 Hz, and 2.5 dB at 3 Hz. Please note that the end of the graph does NOT show 80 kHz.

This entry was created on Monday, August 27, 2007 and is filed under Digital Recorders . Article 29