3.7. Frequency and Impulse Response
The AD converters of the 12Mic 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 12Mic 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.
3.8. Analog input LEDs with Integrated Metering
Each analog input is accompanied by an LED. Shades of green, yellow, and
red represent the current level for each channel. Additionally, each LED shows
the active state of phantom power (yellow), active TRS inputs (white), and
active High-Z impedance on TRS inputs (blue) while pressing the
corresponding quick access buttons.
3.9. Meter Backlight Color and Intensity Reference
The following table describes the signal level represented by the backlight color. Each value corresponds
to full scale, which is equivalent to the reference level of the corresponding input.
Color
Color name
dBFS
Green
-54 (barely visible in low light)
-40 (barely visible in daylight)
-20 (bright green)
Yellow
-5 (strong yellow)
Orange
-4
Red
-1
Red flashing fast
0 (at least three consecutive samples)
Red flashing slow
input muted
RME 12Mic User’s Guide
11
| 3.7. Frequency and Impulse Response