dosaris hat geschrieben: ↑Di 10 Mär, 2020 18:31
Mediamind hat geschrieben: ↑Di 10 Mär, 2020 17:59
Erst leise dann laut und alles während eines Takes. Die Mixpre-Leute bringen auch nur das Level des zu lauten Bereichs auf das gewünschte Niveau. Der Dynamikrange bei 32 Bit liegt, sonst bitte korrigieren, bei über 1500 DB.
da geht einiges durcheinander:
der
Adressraum ist 32 Bit wenn das Signal erstmal im Rechner drin ist.
Aber es klemmt weit davor:
Real aufnehmbar sind mit dem Micro + Vorverstärker + ADC noch nicht mal ansatzweise die 144dB (24 Bit) SNR.
Ohne sämtliche Produkte dieser Welt zu kennen gehe ich mal kühn davon aus,
dass es keinen realen 32 Bit-ADC gibt (rechnerisch 192 dB), weil die Rauschschwelle der internen Komparatoren
bereits deutlich höher als das unterste Bit ist. d.h er mag 32 Bit Auflösung ausgeben,
aber der nutzbare Signalumfang ist weit darunter. Er codiert lediglich sein eigenes Rauschen in voller Auflösung.
1500dB existiert in der realen Welt schlechthin nicht.
Erklärungen von Sounddevices direkt:
Analog Microphone Preamplifier
The analog microphone preamplifiers in the MixPre II recorders have >142 dB of dynamic range. This allows the input to capture the entire dynamic range of any connected microphone. The custom-designed topology, with large-geometry, discrete transistors connected in a class-A configuration, result in the lowest noise and distortion possible. The preamplifier is so quiet that connected microphones will generate more noise than the preamplifier. Regardless of MixPre’s gain setting, the microphone’s signal and its noise is heard, not the preamplifier. It is the definitive “transparent” microphone preamplifier.
Multi-Stage A/D Converter
The analog-to-digital converter is one of the most important stages in a digital recorder. The best audio A/D converters presently on the market yield roughly 130 dB of dynamic range. This on its own is quite excellent, but not good enough to capture the entire dynamic range of all microphones. Sound Devices patented a method of combining multiple fixed point 32-bit A/D converters. This unique combination results in an A/D conversion stage which yields over 142 dB of dynamic range. The output of this stage of the hardware is 32-bit floating point audio data.
32-Bit Float Processing
It is worth reviewing the technical article on the math behind 32-bit floating point. The important point to remember is that a 32-bit floating point representation of an audio signal exceeds 1500 dB of dynamic range, so virtually any amount of gain can be added to or subtracted from the signal. Said another way, it is impossible to clip the signal or bury the signal in the noise floor. All processing, including gain, EQ, routing, etc., is performed using 32-bit floating point math.
How Is 32-Bit Float Different From 32-Bit Integer?
32-bit float signals should not be confused with 32-bit fixed point. A 32-bit fixed point signal can accommodate considerable dynamic range, roughly 192 dB. While 32-bit integer offers a much larger dynamic range than 24-bit audio’s theoretical 144 dB, it pales when compared to the 1500 dB available to 32-bit float signals. If, for instance, processing adds 90 dB of gain to the 142 dB of dynamic range coming in, then 232 dB would be needed to capture this signal with no loss in headroom or noise. 32-bit float can do this, and 32-bit integer cannot.
Quellen und noch mehr dazu hier:
https://www.sounddevices.com/how-is-a-3 ... -recorded/
https://www.sounddevices.com/32-bit-flo ... explained/
