A question about VU meters.

Hi!

I've recently downloaded PSP's VintageMeter because I want to start being more careful about not "hitting the red" when I make my beats.

My question is: which unit does VU meters - or perhaps PSP VintageMeter in particular - measure in? Is it dB? Because I don't understand why it begins at -20 (= no sound) and 0 is where it peaks (before it goes into the red zone). Is this dB?

If it is dB then I don't understand it, because I found this Decibel Loudness Comparison Chart (http://www.gcaudio.com/resources/howtos/loudness.html) that says that 0dB is the lowest barely hearable sound.

I know that when mixing it's best to keep the VU meter at about -1 so that it don't hit the red zone.

But is the VU meter measured in dB, and if so then why does the Loudness Chart state that 0 is the lowest hearable dB when VintageMeter starts all the way down at -20?

Hope this was understandable.

Thanks in advance!

PSP VintageMeter clearly operates in VU or PPM as shown on the plug-in's interface.



An SOS article that may help your understanding of the different metering standards and how they compare.

http://www.soundonsound.com/sos/jun00/a ... etring.htm

There chart you refer to appears to be referencing analogue sound measurement, with a DAW we are more concerned with the digital domain where the measurement concepts are different and typically 0db refers to the maximum sound level, allowing for some headroom.

If the red 'clip' indicator lights briefly it does not necessarily mean the audio will be distorted, but you are very close to that point.

1st Edition wrote:If it is dB then I don't understand it, because I found this Decibel Loudness Comparison Chart (http://www.gcaudio.com/resources/howtos/loudness.html) that says that 0dB is the lowest barely hearable sound.

dB is a "dimensionless unit" -- which means it's not an absolute value. a number in decibels is only meaningful relative to something else. so that chart is telling you the "loudness" in dB of various sounds relative to the quietest sound you can hear.

on audio equipment 0dB is chosen to be somewhere near the maximum volume it can handle, so all levels below that are negative, because they're quieter than the maximum and so are below 0dB

check the settings of the psp vintage metering:




VU metering... you can set your 0 level in dBFS. when mixing all tracks playing, leave peaks around -10dbfs. MIN -6dbfs. so if you want to calibrate the psp meter, dial the 0vu reference level to about -10dbfs.

24-bit audio has plenty of headroom vs 16-bit audio. you don't need to go anywhere near 0dbfs when mixing.


analog vu metering is more complicated.

If the red 'clip' indicator lights briefly it does not necessarily mean the audio will be distorted, but you are very close to that point.

you can use this for master channel metering:

http://www.solid-state-logic.com/music/X-ISM/index.asp

shows when a signal exceeds 0dbfs the right way. I would use the x-ism over psp metering any day.


some plugins mimic the analog metering. analog metering response time can't indicate peaks that really occur in the signal:




.... so use the ssl x-ism and have all of your signals at reasonable dbfs levels.