Recording Levels....

mixwiz

Member
Messages
2,433
I'm not quite sure if your asking a question or not. Assuming you are in the digital world, leave yourself head room. Don't record everything just under clipping as it will lead to problems during the mix. It's a bit backwards from what we tape guys were taught as in that era, we were trying to escape tape noise which was much more present if you recorded too low.
 

alamere

Member
Messages
1,566
I'm not quite sure if your asking a question or not. Assuming you are in the digital world, leave yourself head room. Don't record everything just under clipping as it will lead to problems during the mix. It's a bit backwards from what we tape guys were taught as in that era, we were trying to escape tape noise which was much more present if you recorded too low.

I agree wholeheartedly with this... I've heard guys talk about using all of the possible "bitrate" up and recording as loud of levels as possible.. but the best recordings that I've ever made digitally have been the ones in which I left myself a lot of headroom to work with.
 

newb3fan

Member
Messages
1,355
I'm not quite sure if your asking a question or not. Assuming you are in the digital world, leave yourself head room. Don't record everything just under clipping as it will lead to problems during the mix. It's a bit backwards from what we tape guys were taught as in that era, we were trying to escape tape noise which was much more present if you recorded too low.
Hey yeah, I wasn't really posing a question and in my limited number of years of amateur experience in the home setting I did always learn to keep levels low. It was interesting for me to listen to and understand the reasons why from the guy's perspective and thought I would share it. Thanks.
 

Rex Anderson

Member
Messages
5,323
I'm an old pro audio engineer who had to transition from recording on tape with VU meters to digital with much better metering options.

You have to understand how pro audio is designed to operate, i.e it is all based on 0 VU (volume unit) = +4 dBu = 1.228 volts.

Meters can read peak levels or average levels now, not just average (VU). Analog to digital converters are almost all 24 bit now (used to be 16 bit). 1 bit = 6 dB of dynamic range, so a 20 bit converter has 120 dB S/N. There are no real 24 bit converters (144 dB S/N is not possible due to noise floor of analog electronics).

Most pro audio equipment has +24 dB output voltage capability, some pieces of gear with high voltage rails have +32 dB output. Thus, you have 20 or 28 dB of headroom above +4 = 0 VU.

A/D converters come with fixed or variable calibration for operating level. 0 VU can be anywhere from -15 to -20 dB relative to full scale (0 dB FS). You have to run your front end (mic pre) 5 dB hotter to hit 0 dB FS on A/D converters that are calibrated at 0 VU = -20 than ones calibrated at 0 VU = -15.

Bottom line is, you need to leave headroom on your recorder channels. Do not record to 0 dB full scale. If you record so peaks hit -6 dB FS, that is 1 bit of information off your 20 bit converter.

Source material (vocals guitars, drums etc) have widely varying transients. Some sources have big peaks and low averages, others are not very dynamic. If you have a source that has high peak transient response levels and you record it to peak at -6 dB FS, when you look at the average level, it is very low. That's why engineers use compressors to tame peak levels, so they can get higher average recording levels.
 
Last edited:

newb3fan

Member
Messages
1,355
I'm an old pro audio engineer who had to transition from recording on tape with VU meters to digital with much better metering options.

You have to understand how pro audio is designed to operate, i.e it is all based on 0 VU (volume unit) = +4 dBu = 1.223 volts.

Meters can read peak levels or average levels now, not just average (VU). Analog to digital converters are almost all 24 bit now (used to be 16 bit). 1 bit = 6 dB of dynamic range, so a 20 bit converter has 120 dB S/N. There are no real 24 bit converters (144 dB S/N is not possible due to noise floor of analog electronics).

Most pro audio equipment has +24 dB output voltage capability, some pieces of gear with high voltage rails have +32 dB output. Thus, you have 20 or 28 dB of headroom above +4 = 0 VU.

A/D converters come with fixed or variable calibration for operating level. 0 VU can be anywhere from -15 to -20 dB relative to full scale (0 dB FS). You have to run your front end (mic pre) 5 dB hotter to hit 0 dB FS on A/D converters that are calibrated at 0 VU = -20 than ones calibrated at 0 VU = -15.

Bottom line is, you need to leave headroom on your recorder channels. Do not record to 0 dB full scale. If you record so peaks hit -6 dB FS, that is 1 bit of information off your 20 bit converter.

Source material (vocals guitars, drums etc) have widely varying transients. Some sources have big peaks and low averages, others are not very dynamic. If you have a source that has high peak transient response levels and you record it to peak at -6 dB FS, when you look at the average level, it is very low. That's why engineers use compressors to tame peak levels, so they can get higher average recording levels.

Rex I appreciate your time and this post. It breaks things down simply for the less educated, like me.
 




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