Calibration levels for DAW

[audioboy6]

I'm in the process of recalibrate my protools rig and was wondering what level most people are calibrating there systems to. I've pretty much always done -18. But i just worked with an Engineer that does -12. This got me thinking. What is everyone else calibrating to? So what are you guys using?

[tommyd]

Good topic! Recalibrating my HD rig is on my "to-do" list and I've been thinking about this very subject. -18 is were I'm at now, wondering too what the general opinion is.
TommyD

[jonnyclueless]

-14 in and -14 out. -18 hits the console waaaaay too hard for me.

EDIT: Since I am usualy using the Digi 192 interfaces, they won't cal to -12 for some reason. The pots don't go far enough.

[paterno]

Originally Posted by audioboy6

I'm in the process of recalibrate my protools rig and was wondering what level most people are calibrating there systems to. I've pretty much always done -18. But i just worked with an Engineer that does -12. This got me thinking. What is everyone else calibrating to? So what are you guys using?

I'm at -16 for my PTools rig.

John

[jdunn]

Check out this thread. I think it's more for A/D converter input calibration, but may be useful nonetheless. Basically the guy is calibrating 0 dbv=-24dbfs on the input side so he can drive the mic pres harder going in, thus increasing signal to noise ratio. More headroom.

3D Audio post

As far as D/A feeding your console, I have no idea.

[jonnyclueless]

And more distortion.

[jdunn]

Yeah, if you use dirty sounding mic pres and crank your levels so that the meters are constantly pegged. Most people think preamps sound better run hot. That doesn't mean that you have to turn the gain all the way up!

-24 dbfs may be a little extreme. maybe around -20 would be best. I've always thought that -16 was the 'standard', but some people obviously do it differently.

[tony666]

Shouldn't this depend on the headroom of you analogue system (and how hard you hit your preamp). Most systems can output 22dBu (or more) , that makes 18dB headroom at +4dBu. So 0 Vu should be at -18dBFS , 0dBu = -4VU should be at -22dBFS?

I could be wrong but this is what I understand of it at the moment

[jdunn]

Something like that. All these numbers confuse my primitive wookie brain rather quickly.

If your mic pre has +20dbv of output, and let's say you only want to drive them to around +16 to keep things clean. Then 0 dbv on your A/D converters should be calibrated to somewhere around [EDIT] -20 dbfs (digital full scale).

That way, you can drive the output of the mic pres to a peak of +16 dbv for peaks around -4 dbfs on your DAW. The mic pres shouldn't distort, as you're leaving 4 dB of headroom below their max output. Same with the converters

I'm not sure if I'm off by 4 dB here because balanced is +4, but anyway. Probably wrong, who knows. That's the way it makes sense to me.

[EDIT] I was half asleep when I wrote the original post. Now do I have it right?

[5down1up]

i guess it just depends on what youre doing ...

recording voiceovers is just different compared to recording an " i kill my drumset "
drummer . the way i understodd the idea of calibration ( still learning ) is to get the levels right without distortion . in fact of calibrating is done with a vu using a static signal this has nothing in common with recording " acoustic " instruments .

if u ever watched a peakmeter besides an vu you prolly know what i am trying to say ( i guess i said in on that board like 5000 times already ) .
hit a snare for instance , you wont see a lot of level on a vu ( fast sound that is ) but you will easily see whats going on using a peakmeter . a peak of ~12db is easy for instruments like that ( think about an whole orchestra etc. )

in fact of digitals max level is 0.0 we better leave some headroom or well get that nasyt digital distortion .

hope that helps ?

[espasonico]

One good thing about Digidesigns 192 i/o is that you can have 2 calibrations and you can choose wich one to use depending on the application.

[deeewight]

Originally Posted by jonnyclueless

-14 in and -14 out. -18 hits the console waaaaay too hard for me.

EDIT: Since I am usualy using the Digi 192 interfaces, they won't cal to -12 for some reason. The pots don't go far enough.

maybe I don't get this...wouldn't -18 actually hit the console softer..I am probably backwards but just trying to make it make sense in my head. Is it because you would be putting things in four db hotter?

dwight

[ilovesound]

Hello ... I am running a Protools HD system with a digital 192 that feeds an AD-16x and DA-16x ... the outputs of the DA-16x go into my Chandler Mini Mixer. When bouncing down a song, the output of the Chandler goes to the inputs of my Neve 33609 which then feeds into a couple of channels of the AD-16x.

How does one begin to calibrate the system so that everything is set properlly etc ... can somebody recommend a resource that describes this calibration process step-by-step???

I find that the out of the Chandler is hitting '0' but when I try to record back in, the level is really low. Any ideas?

I also plan on running my external effects through my system as well (PCM91,PCM80,PCM60,PCM42,H3000D/SE).

Thank you.
Ian

[5down1up]

step by step

you take a 1khz sine wave tone and send it to a VU unit . adjust the level of the sine tone till the VU meter shows 0dbvu . send this signal to your apogee AD and watch your protools meters . ( depending on how the apogee ins are calibrated , youll see this level , f.ex -18dbfs etc. ) . to recheck your DAs , you simply patch the desired out to your VU unit again and it should show 0dbvu again . if it doesnt you need to adjust the outs . if thats working , hook up the DAs to your analog gear and check the levels on them again . ( most analog gear doesnt have the calibration option so make sure you set the levels on the apogees right ! )

if u send out now that sine tone @ 0DBVU or xDBFS to your analog gear , it should show 0DBVU again . so you see already that the DBFS ( digital scale ) is relative and you can adjust it to your taste .

the " problem " you have bout sending 0DBVU ( dont know the chandler mixer ) to the apogees again you should get a signal f.ex like -18dbfs again [ prolly higher , cause a sine tone is a static signal , which doesnt really exist in the real world besides synth , thanks god for the comps ) . so if you wanna have an higher level being captured you need to recalibrate some inputs on the apogee ADs to get a " hotter " level like 0DBVU = -10DBFS ? [ if thats really needed ] .

i think a good way of calibrating is going the -18DBFS way . in reality , it will take some level to show 0DBVU f.ex recording a snare hit . it will easily peak over +12 db and your " slow + lazy " VU will not even recognize it .

so calibration just helps you to get an " good " signal into your digital world . the way you deal with it is as always ... UP TO YOU

[jonnyclueless]

Originally Posted by deeewight

maybe I don't get this...wouldn't -18 actually hit the console softer..I am probably backwards but just trying to make it make sense in my head. Is it because you would be putting things in four db hotter?

dwight

It can be pretty confusing. We're talking about the reference level. I try to visualize on the DAW faders where the reference level is nd that = 0 VU. So as you move that reference level lower, the amount of ditance (visually only) from that reference level to where your audio levels are is greater, thus a hotter signal. So if your signal is say 10dB above your reference, that's +10VU for -14dBFS, and +14 VU if -18dBFS reference. Hopefully I didn't make it even more confusing.

Now because it's a reference, it's relative to how hot you print. -18dBFS can be perfectly fine if you are printing at moderately low levels and leaving a ton of headroom. But the problem is that most people record hot and as close to 0dBFS as possible (which is perfectly fine). In these cases, using -18 means that you have to distort the analog gear's output to reach levels that hot, and you distort the analog gear's inputs coming back off of PT when printing that hot.

My personal preference is to use -14 (since PT HD doesn't go to -12) so I can print hotter w/o overloading analog gear. As opposed to using -18 and just not using the extra bits. When dumping from 2" to a DAW sometimes use -18dBFS which is a lower level coming in (more confused now?).

[jakerbean7]

Originally Posted by jdunn

-24 dbfs may be a little extreme. maybe around -20 would be best. I've always thought that -16 was the 'standard', but some people obviously do it differently.

0dBv=-20dBfs is technically the "standard". At least according to SMPTE. ProTools defaults to -18dBfs for whatever reason.

I'm kind of fuzzy on the logic used by the guy at 3D. (It could easily be my ignorance) But with headroom defined as "the difference between nominal operating level and distortion" wouldn't the "worst of his pres" have up to 24dB of available headroom with his settings instead of 3dB like he suggests?

Jake

[5down1up]

this stuff has been discussed a 1000000000000000000000000000000000³ of times . use the search function

dont get me wrong

[jonnyclueless]

Originally Posted by jakerbean7

0dBv=-20dBfs is technically the "standard". At least according to SMPTE. ProTools defaults to -18dBfs for whatever reason.
Jake

I may be wrong, but I believe that is for broadcast where they can't have levels as hot, else it causes problems in transmission (or something of that nature). And thus it's safer to default them to -18 to cover everything, but music isn't limitted by that, hence the higher levels.

[5down1up]

think about dynamics ... would be pretty boring if a piece of music goes 0dbfs through the whole song ( sadly it is this way nowadays ) .
same goes for ciname , tv , etc ... a dialog has another reference compared to the big explosion , thats basically all it is . and thats not different in the analog world .
20db of headroom is not a bad thing .

[jakerbean7]

I didn't really have a question about that. Thanks for answering, though. I was more interested in the link from jdunn.

The lower level is to adjust for the discrepency in digital/analog gear and metering. A nice analog console has a nominal level of 0dBv but headroom up around 27dBv. Because there is nothing but square waves above 0 dBfs they had to set a standard for calibrating between the two scales.

Jake

[5down1up]

dont really get what ur saying , but if u ever played f.ex a proc drumloop from a f.ex sample cd or simply a mastered piece of music using your DAs set to like -14 dbfs = 0vu youll figure that the ins of your mixer shows like +~ 14dbvu++ if you dont lower your daw channel faders . if u throw like a trim plug on the channel and adjust like -14db you get like +~0 dbvu++ on your desk .

so if you have your system calibrated to -20dbfs = 0vu and you playback a fullscale signal , youll get at least +20dbvu ... which simply ... SUCKS

but in the digital world it aint a prob to lower the faders ... so its actually no prob at all . if u dont like screw drivers for calibrating nightmares use the trim tool or your faders .

[jonnyclueless]

reference level doesn't change the dynamics, you set the reference level based on the dynamics. If it's something like Tv/classical/jazz that needs a lot of dynamics, you set it lower. If you are doing pop/rock/rap music, then a lot reference level can be a waste of bits since there is little dynamics.

[The Alamo]

Originally Posted by jonnyclueless

reference level doesn't change the dynamics, you set the reference level based on the dynamics. If it's something like Tv/classical/jazz that needs a lot of dynamics, you set it lower. If you are doing pop/rock/rap music, then a lot reference level can be a waste of bits since there is little dynamics.

Well said, jonnynotsoclueless ...
If you're doing rock-pop-...stuff, you'll be ok with 0VU=-14dBFS. That'll give you 14 dB of headroom above 0VU...You'll probably only need 4 anyway .
You can leave it at -18DBFS too if you want and adjust all the line trims on the console (do you work on a console?).
The place where I mix has the A trims of Pro Tools set to -14, and the B trims to -18. Best of both worlds. Although no one ever switched to the B trims yet.

(Remember) The Alamo