Interconnectivity and Calibration Flashcards
common meters
analogue peak VU (volume unit) analogue dBu digital peak digital RMS
max operating level on digital meters
zero
any further and you get undesirable distortion
max operating level on analogue meter
zero is optimum, levels can go beyond without distortion
VU meters–slow or fast?
slow
what information do VU meters give
give average volume, signal rise time is too show therefore does not show peak levels
DEF:
headroom
the range between your operating level and the system’s clipping point
DEF:
gain staging
the process of setting your levels throughout the recording chain so your signal is loud enough to avoid excess levels of unwanted noise but also give enough headroom to avoid the audio distorting in unpleasant ways
DEF:
signal to noise ratio
(SNR or S/N)
the level of noise in a recording in relation to usable signal
DEF:
clipping point
where the signal level is so high that it cannot be accomodated by the system and thus becomes distorted in a way that is detrimental
DEF:
noise floor
the point at which signal is so low that hiss and other system noise begin to have a detrimental effect on the quality of the capture
what are the two operational extremes in a system that captures and reproduces audio?
the noise floor and the clipping point
What is the voltage on a VU meter at zero?
0.775 Vrms
What do peak hold meters show?
averaged signal level and peak signals, displaying the average as a solid bar and the peak value as a floating point at the top of the meter
What is the standard analogue operating level for pro audio equpment? (dBu and Vrms)
+4 dBu = 1.227 Vrms
what is the nominal operating level for consumer audio equipment? (dBV and Vrms)
-10 dBB = 0.316 Vrms
DEF:
line level
analogue pro audio operating levels, +4 dBu = 1.227 Vrms
What is the rule of thumb for acceptable levels for pro audio equipment ? (think clipping)
Peaks up to 8dB abouve 0 VU (+4dBu) are acceptable
peaks beyond +12 dBu start to audibly distort (soft clipping)
hard clipping starts around +18 dBu (+24 dBu on high-end systems)
why is a peak meter needed for digital audio?
Because digital distortion is much more detrimental and it’s important to have a meter showing the moment of the signal clip
what scale does the digital metering system use?
dBFS
What is the highest possible figure in the digital domain?
0 dBFS, clips above that
what meter is used to analyse digital average levels in a DAW?
dBFS RMS meter
at what level do analogue-modelled plug-ins work best?
the equivalent of 0 VU, imitating the originals
what should peak values be for every channel in your DAW?
between -6 dBFS and -12 dBFS
what is the recommended digital levels when calibrating an analogue VU meter on a hybrid system
- 18 dBFS (UK) = 0 VU
- 20 dBFS (USA) = 0 VU
0 VU = _______ AC volts RMS (pro)
1.227 Vrms
Who developed the K-System?
Bob Katz
What is the K-System?
three-tiered monitoring gain and metering system which changes dependant on application
what is the K-system designed to do?
- allow you to easily return to a calibrated listening level that is a compromised between the point where your ears have the flattest frequency response (Fletcher-Munson) and a comfortable listening level that can be used for extended periods of time without ear fatigue
- optimise headroom and make sure dynamic range isn’t excessively reduced
What are the three tiers of the K-system?
K-20, K-14, and K-12
What would you use K-20 for?
music with high dynamic range (ie. theatre film mixes, classical music)
How much headroom does K-20 have?
20 dB
What would you use K-14 for?
mixing standard pop-rock music
How much headroom does K-14 have?
14 dB
What would you used K-12 for?
programs for TV or radio broadcase
How much headroom does K-12 have?
12 dB
On a K/RMS meter what does 0dB ALWAYS equal?
83 dBC SPL with pink noise
what three factors do you need to know if integrating the K-system into your workflow?
1) must use standardised monitor levels outlined by the K-system. each monitor should be set to 83 dB with an SPL meter, which should be set to C weighting with slow attack
2) must use k-Meter on mix bus to make sure entire mix is falling within required levels
3) K-meter is meant for entire mix not individual channels and shouldn’t be used to determine correct channel levels
