Metering, headroom, -18dbfs and VU meters...?

[Beastie]

Metering, headroom, -18dbfs and VU meters...?

Hey Guys - help me out here im getting confused...

I have been used to working ITB up until a while ago....

Now i am on a console and running logic outputs up through channels on the console...

Metering is confusing the hell out of me....

I believe the console is set at -18dbfs as are the apogee ad16's da16x's

I have soft limit engaged on AD16x's....

Now when recording, what is my optimum level - my ultimate goal????

I try to make sure when the input reaches logic it is on average around -12 to -6db with max peaks at -3 to -6db....

- However one thing i have noticed is when i am peaking at say -3 ( a particularly loud transient) the mono track on logic is -3db but the stereo output is metering red - why is this and how do i resolve it????

- The is a VU meter on this console to so am i right in thinking -18dbfs in the digital domain is the same as 0dbV on the VU meters? or am i way off track?

I guess i am trying to get a system i can trust and work with to get the best result possible and be something i can understand and rely on!!!!

The main thing i have always followed is stay out of the red and don't worry too much about input levels being low at 24bit...

Is this a correct statement?

Thanks for your time...

Peace......

[psycho_monkey]

you're not doing much wrong.

Vu meters don't read dBv though - they read dBVU! which is +4dBv on a pro level console....so -18dBFs reading 0dBVU is a common calibration yes.

What do you mean by "mono track" but "stereo output" - what happens when you run it 1 to 1 (ie input 1 comes out of output 1)?

if your fader in logic is turned up by 3dB of course, that might be enough to clip the output - or at least show it as clipping.

I wouldn't use soft clipping on the AD16X, but then if you're staying out of the red, it doesn't matter really.

[Beastie]

Originally Posted by psycho_monkey

you're not doing much wrong.

Vu meters don't read dBv though - they read dBVU! which is +4dBv on a pro level console....so -18dBFs reading 0dBVU is a common calibration yes.

What do you mean by "mono track" but "stereo output" - what happens when you run it 1 to 1 (ie input 1 comes out of output 1)?

if your fader in logic is turned up by 3dB of course, that might be enough to clip the output - or at least show it as clipping.

I wouldn't use soft clipping on the AD16X, but then if you're staying out of the red, it doesn't matter really.

Thanks man!

What i mean is when recording on a mono input track, its output is the left side of a stereo OP and that is going into the red - is this to do with pan law? and how should this be set for this kind of setup???

I think at the moment i have pan law set to -3db compensated on logic? is that not the right setup as we are OTB? (even though sometimes we sub mix to stereo outputs.......)

Cheers!

[psycho_monkey]

pan law should only affect what's happening in the centre of a stereo track. -3dB means the centre signal drops by 3dB (same as when you pop the pan button in on a Neve) - in the analogue world, the best compromise - if it was totally linear, you'd get an increase in level in the centre, which would mean things get noticeably quieter when you panned out to one side, due to coherent signals summing in the centre - I've probably not explained that very well!).

Anyway, what's the through signal like? ie if you send a tone at 0VU into your interface, pan the mono track to one side, output it again into the desk, you should have -18dBFs in Logic, then 0VU at the console again. If you don't - something's not lined up right!

Which doesn't actually explain why the stereo output should be showing clipping though, unless as I mentioned your audio track fader has been turned up at some point.

[Beastie]

Originally Posted by psycho_monkey

pan law should only affect what's happening in the centre of a stereo track. -3dB means the centre signal drops by 3dB (same as when you pop the pan button in on a Neve) - in the analogue world, the best compromise - if it was totally linear, you'd get an increase in level in the centre, which would mean things get noticeably quieter when you panned out to one side, due to coherent signals summing in the centre - I've probably not explained that very well!).

Anyway, what's the through signal like? ie if you send a tone at 0VU into your interface, pan the mono track to one side, output it again into the desk, you should have -18dBFs in Logic, then 0VU at the console again. If you don't - something's not lined up right!

Which doesn't actually explain why the stereo output should be showing clipping though, unless as I mentioned your audio track fader has been turned up at some point.

Ummmnn nope - lol

Tone at 0dbVU on analogue meter with tone from desk to mix and track buses....

Input into logic at -20db (coz thats the default on duality atm...)

shows as -20db on logic and -20db on stereo OP unless i pan the input channel signal far left or right then it attenuates to -17db...

so that all seems to be in order - however - is the pan law set correct at -3db compensated in logic?

With regard to recording - its seems as though there was some sort of pilot error in the heat of the moment (????) - but recording is ok - so all good ;)

Thanks for all your pointers!