Hi There,
I am having a hard time figuring out the actual track levels on my hard-drive. When recording, both PFL and Qu-Drive multitrack metering tell me I´m hitting close to zero (which I suppose refers to -18dBFS?). When I transfer the tracks to Logic, they are nowhere near that level, I´m more like in the -35 region. Would not want to normalize every track to get healthy gain, am I missing something here?
B.R.
I am having a similar issue with stereo recording.
My mic levels are near the 0db on the mixer and sound great in the speaker system,
but when playing back the file either through the mixer or on the computer the sound level is very very
low.
Normalise in the DAW - the (band limited) audio is perfectly captured, and can be scaled happily.
The levels on the QuDrive are the levels in the desk - you need headroom for transients and the noise floor is a VERY long way down, even at -35dB
So, you are basically saying that the Qu-Drive- metering has no reference to any real-world units? I’ve been trying to optimise my gain structure, and hit the inputs and busses as hot as possible…with adequate headroom,of course, but it feels weird that the DAW is showing you something completely different. I mean, we have input gain controls to set the levels, and I sort of expected the metering to reflect those. Especially as these are individual tracks, and saturating a buss is an irrelevant issue, because the recorded tracks are sent to the hard drive directly.
Having just typed this I’ve gone back to the oroginal post and realised that the OP probably knows much of this anyway…
It is such that 0dB is digital full scale. dB is a relative unit, but you really don’t want to get close to 0dbFS in live scenarios in the digital domain, because a transient will generate digital clipping - and very bad things happen in that direction.
The real issue with levels is the noise floor, which can be described by the bit depth of the recording.
Human hearing can hear about 15 bits of audio, a CD is 16 bits, the QU is 24 bits - specifically so that you can leave lots of headroom and still have better audio range than a human can hear.
An audio cassette is normally more like 5-6 bits deep (because dithering and tape hiss are interchangeable) with a theoretical cap of 9 bits… High end reel to reel could just about hit 13 bits.
Once in the digital domain it is trivial to boost the levels in an audio editor - it is a lossless process, so normalise away.
Videos/Digital Show and Tell - XiphWiki is worth reading/watching
Gah - my edit time has expired - I meant to paste this link instead.
https://people.xiph.org/~xiphmont/demo/neil-young.html
The first link is still valuable, and talks about all sorts of digital domain issues - why we don’t need to be concerned about various transformation.
The second (i.e. this one) is looking more at the human ear, and why 24 bit is overkill (and 192kHz)
We use 24 bit, and 48kHz, for good reason (and they are explained in the article) but for produced output work - 44kHz/16bit is perfectly transparent anyway…
If you’re recording from direct outs, have you checked your direct out trims or follow fader settings?
Just as a sidenote: I did a recording the other day, and vocals were running very hot. They did not clip, but occasionally tickled red in the metering. When I got home, the peak amplitude for the entire recording was at -3.53dBFS. There’s nothing wrong with the gain structuring of Qu-Drive.
Well, I thought recording via USB to hard drive would just mirror the input gains, no other trims required… and that’s what the Qu-Drive meters are telling me- they show exactly the same levels as PFLs.
Hi Stonepiano,
Indeed, -18dBFS is the reference point of the system. For example, a sine that reads 0dB on the Qu metering would peak at -18dBFS in the recording. The metering point is not necessarily the same as at PFL though. When recording in “Insert Sends” mode, the metering point is at the insert send point. When recording in “Direct Outs” mode, the metering point will follow the direct out accordingly.
DC
Depends on where your recording point is. There are a couple of options of “CH/ST Source”, and the Direct Out option is further adjusted in the Routing screen.
See section 10.15 for details on the routing.
Assuming the noise floor is sufficient - which it should be - then there is no harm to the audio in a digital normalisation…
Thanks Guys,
…you live & you learn… I need to check out my “Points of Send”. As to my recordings so far, I wish Logic will accept a “cmd-A” for normalizing every track at one go, so I can leave it working… it takes ages to fix a concert recording track by track.
Yes - it would take as much time, but you could go to sleep in the meantime…
I somewhat do not understand the problem with normalizing. I’m doing DAW recording for decades now, all with a decent headroom and any DAW I’ve used so far has a gain pot per track to raise volume as required. This happens on the fly, never touched a wave file after recording.
Andreas, if I import a file to my DAW, and it appears at -35dBs, I have a a problem: I have to insert a gain plug-in into every single channel, just to find that it does not have enough range, so next you end up pushing the channel fader all the way up, at least in Logic even that may not be enough- and you have totally messed up your session. I want most of my mix sit nicely below zero, visually, that is. That’s why I need to normalize.
Sure, -35db really is low level and should be focused first during recording. As already written levels around -18dBFs should be expected and I believe that also Logic can handle that nicely.
Right, those kinds of levels occurred only because I thought what I was seeing on the metering were the the actual levels going into the hard drive. In my opinion, you should get what you see. But no.
Right, those kinds of levels occurred only because I thought the metering would reflect the actual levels going into the hard drive (because it’s the qu-drive metering!) I think you should get what you see. Turned out not to be the case.
You get what you see, but you won’t get positive dBFS levels. The reference is the absolute maximum value (and hence full scale). That’s why -18dBFS was picked, to give a reference relative to a working level chosen by the manufacturer. If you want dBFS, subtract 18.
I ask that you do your homework rather than get frustrated and blame the tools. They work just fine.
-18 is more or less a universal reference with console manufacturers. What I am trying to put across here, is:
What is the the point in having a metering display that doesn’t give you instant information on what is actually going on? Besides, I’ve been hitting zero, getting below -30 levels, your arithmetic does not work, and neither does the metering. You can go on defending badly implemented functions, I want to know what is happening, without a pocket calculator.
It is going to be interesting to see what kinds of levels will be displayed, after I’ve visited the routing menus, and trimmed everything up 10dBs… which of course adds up to around -25dBs, well below 18.
You have never been helpful with any of my issues, so save your breath.