RME Audio ADI-2 Pro, User Manual

Page: 34 / 114

34
User’s Guide ADI-2/4 Pro SE - v 1.0
15. Top Screens
The ADI-2/4 Pro SE has four different meter screens: a global level meter that shows all signal
levels of all I/Os simultaneously, an Analyzer showing the audio signal content on the analog
inputs and both analog outputs 1/2 and 3/4, a state overview showing the digital states of AES,
SPDIF and USB, and a dark Volume screen with comprehensive information.
Pushing the small encoder 1 or 2 while any meter screen is active cycles through all meter
screens. To quickly call them up simply press any of the 4 buttons one or two times.
15.1 Global Level Meter
Shows the signal present at all inputs and outputs (except USB). The upper labels refer to inputs
Analog 1/2, AES and SPDIF, then outputs Analog 1/2, Analog 3/4, AES and SPDIF.
At sample rates above 192 kHz AES and SPDIF are grayed
out as they are no longer functional.
All level meters (vertical and horizontal) of the ADI-2/4 Pro
are peak level meters with peak hold function. The horizontal
Post FX meters are band limited to 45 kHz at higher sample
rates. OVR (Over) are displayed in red color at the upper
end. For digital I/Os, Over appears when the signal is at the
maximum possible level. As usual in digital audio, Over is
already displayed even if there is no real overload.
OVR appears for all analog outputs at +2.5 dBFS, since the ADI-2/4 Pro SE has this digital head-
room. In the horizontal meters of the EQ and Analyzer, the current peak hold value is displayed
numerically on the right. Levels below -119 dB appear as UFL (Underflow).
15.2 Analyzer
The Ana
lyzer is based on RME’s famous Spectral Analyzer
in DIGICheck. It uses 29 biquad bandpass filters for high
separation between the bands, providing outstanding musi-
cal visualization. Using carefully selected attack and release
times the display is responsive, but still easy to read. On top
it uses RME’s own
Max LR technique to prevent 6 dB higher
level display for monaural signals, and zero display with out
–
of-phase signals.
Thanks to the high-resolution IPS panel even smallest details are clear to see. Music content
analysis is possible even when viewed from a greater distance.
The Analyzer operates at any sample rate, and even with DSD. There are no parameters to
change, and the shown frequency range is always the human audible range, 20 up to 20 kHz.
To be able to also show DC content the lowest band is not a band-pass filter, but a low pass,
catching the whole range from 0 Hz up to 30 Hz. With some unusual signals it therefore can
happen that the level shown will be a bit higher than expected.
As opposed to most other solutions no FFT (Fast Fourier Transform) is used. RME's Spectral
Analyzer performs a true band-pass filter calculation, as in professional hardware devices. The
frequency distance between the filters is scaled matching human hearing. The highly optimized
code allows to run a 30 band analyzer with 60 dB range, sharp filters and 0.5 dB steps accuracy
per band, on the ADI-2/4 Pro SE DSP, even at 768 kHz sample rate.