Recording and Mixing Volum e...

[DonaldChang]

Ok...
your supposed to record your individual tracks (kick ,snare,guitar,piano ETC) as high as you can without clipping, but mix down it all down to like -6 DB so the person who's mastering has a little headroom

 

[RAMI]

Ok...
So is there a question in there somewhere??? Or are you waiting for a drum roll before actually asking it???

 

[AlexW]

I think he's asking why record individual tracks hot and then reduce them down when summed.

Actually, the hot recorded signal idea applies more to analog (where you're trying to improve the signal-to-noise ratio) or 16-bit digital (same idea). Most digital recorders now operate at 24-bit, so recording a signal near 0 dBFS isn't required to get a noise free track. Most now recommend recording your 24-bit tracks around -6 dBFS as well.

 

[kats]

Leave headroom when tracking (digital) as well - not just on the summing. You can clip your track without seeing the "red lite" when using filters. -6 is recomended, by those who know far more than me.

 

[gtrman_66]

If you are recording at 24 bit, don't push it, you simply don't have to. My track meters may be peaking at anywhere from -6 on the hottest peaks to -15 or below, depending on what's on the track.

When I'm setting up individual track levels, I'll ask each player to play the loudest they expect to play on the piece, then I'll set the track level between -15 to -20 or so, because I know they are going to play louder once they all get together and start groovin'. From there, I'll make a few fine adjustments and then just let everything land "where it wants to be" unless someone starts nailing a track.

I was recording some really dynamic stuff last week where there were quiet passages to some really loud bashing and everything. I had peaks in the soft passages between -30 to -36 or so for some instruments and the loudest stuff between -9 to -12, occasionally saw a -6. It all came out sounding fine to me.

 

[DonaldChang]

so the loudest I should track is at -6DB?What's the quietest I should track?What volume should I mix down to?In this thread I was just confused about what volumes I was supposed to record at, and what to mix down to, no trick question or anything .

 

[gtrman_66]

If memory serves, (someone please correct if I'm having a brain fart) every 6db= 1 bit. So, if you are working in 24 bit, 6x8=48, 24-8=16. In other words, you don't hit 16 bit resoultion until you get all the way down to -48db. What all this means is you have plenty of headroom in the 24 bit format, so there is really not any advantage to pushing the envelope and risking burning up tracks unnecessarily.

Usually, when I mix down, I shoot for most of my peaks to come in between -12 and -6. I might get a few strays at -3, then there always seems to be that one damn peak in the mixdown that hits near the top for a few milliseconds, which I don't worry about. I just highlight it in the editor and turn it down.

Mixdown is not the place to get your mix "loud". During mixing, you are shooting for balance, tone, texture and space. Mastering is generally the process where the "loudness" is achieved.

 

[Massive Master]

Sounds good to me - I'm a -6dBfs type. Tracking and mixing.

Think of it this way also... If you have two tracks that peak at -6 at the same time, you just clipped. Is there really any reason to smack the ceiling when you're going to have to bring all the faders down anyway?

The other "more interesting" anomaly I find with engineer's who work this way is that they're mixes sound MUCH better in the end - A small part of that might be attributed to less D-A reconstructive distortion (which you really don't have to worry about below -6dBfs). I would imagine most of it is that they're concentrating on the sound instead of the meters. When you're tracking with the "meat" of the signal riding around -10 or -12, you just don't have to worry much about clipping.

 

[DonaldChang]

but after tracking at a loud volume, you could always turn the faders down a little?I was just asking because I was told to record as hot as you can, but I guess thats just for tape.

 

[sweetnubs]

+6, 499, analog only baby. Yeah baby!

 

[amra]

Isn't there an advantage to tracking a little hotter due to the whole "signal to noise ratio" thing? If you track too quiet, then when you boost the gain later, you also boost the noise...

correct me if I am wrong, here...


amra

 

[Massive Master]

You DO want to get a "good" level for that reason. You DON'T want a HOT signal for all the others - As stated before, if you've got two tracks that peak at -6 at the same time, you just clipped. In a crowded mix, you're likely to have several hitting around their peak area frequently. You're almost always going to be attenuating anyway.

 

[DonaldChang]

But theorietcally arent you at 23 bit when you go less than -6?You can always turn down the volum of the track in your mixing program

 

[SouthSIDE Glen]

As stated before, if you've got two tracks that peak at -6 at the same time, you just clipped.

John (or anyone knowing the answer ),

There is one thing I haven't got a handle on yet. I've done some searching in books and on the net, but I've only found folks dancing around the answer and never quite providing the exact answer:

How does one calculate the addition of dBFS values? For example, what is -6dBFS + -24dBFS? I would like to assume there is a formula for this, but I have yet to actually find it.

Anyone know the answer or have a link to a place that explains it?

TIA,

G.

 

[Blue Bear Sound]

John (or anyone knowing the answer ),

There is one thing I haven't got a handle on yet. I've done some searching in books and on the net, but I've only found folks dancing around the answer and never quite providing the exact answer:

How does one calculate the addition of dBFS values? For example, what is -6dBFS + -24dBFS? I would like to assume there is a formula for this, but I have yet to actually find it.

Anyone know the answer or have a link to a place that explains it?

TIA,

G.

I touch upon it in this article --> Meters, Signal Level, and Headroom

Typically (based on most manufacturer's calibration point), 0VU on an analog mixer's meters corresponds to anywhere between -15 to -12dBFS.

 

[SouthSIDE Glen]

Bruce,

That's a very good article; well written and informative. Good job!

Unless I missed it though, it still does not address the question at hand. Maybe I should elaborate...

I'm not looking for conversion between different dB scales, dBs and voltages, or analog and digital metering. I'm just wondering how to add two dBFS values together. For example if I mix two waveforms in Cubase together, one is a DC signal measuring -6dBFS and the other is a DC signal measuring -24dBFS, what will be the resulting summed level measured in dBFS?

I know, I know I could just do it and see. But that only gives me a single data point for those specific values, it does not give me the actual formula for how to add two dBFS values together.

The quote from John got me thinking of this again. When he said if you add two -6dBFS signals together, you'll clip. This implies that -6dBFS + -6dBFS > 0dBFS. How is that calculated?

G.

P.S. Regarding the illustration in your article, what did you do with all my knobs and buttons on my Pro VLA?

 

[Blue Bear Sound]

Oh I see - sorry - I misunderstood... in that case, it's waveform arithmetic -- the summing of waves, using Fourier Analysis and Fourier Transforms... I found a pretty good link here --> http://rnowik.com/document/7/

 

[RAMI]

My brain hurts.

 

[SouthSIDE Glen]

My brain hurts.

Yeah, mine too. I'm still not sure I see the answer, but it might be implied in there somewhere. I'll have to digest that a bit better...on Tuesday. In the meantime I declare Independance from imaginary numbers and any equations with sigma functions in them.

G.

 

[Cloneboy Studio]

I have a slightly more complicated view on things.

My starting point for a 24 track, 24 bit recording is -12dbfs RMS, with no greater than -6dbfs peaks (meaning if something is peaking over -6dbfs I will drop the level so that the peaks are hitting there, regardless of RMS). Every 12 additional tracks I will drop the RMS and peak level by -3dbfs to make room on the mix buss.

That way, when it comes mix down time, my faders can be where I expect them to be from my old analog days.

Seems to work well. When I implemented this technique last year the quality of my recordings did go up. Prior to that I stuck with a religious -12dbfs RMS/-6dbfs peak. When I started doing bigger projects (and by golly I love to use 2-3 mics per guitar track and 3-4 takes of guitar... adds up to a lot of tracks quickly) I ran into that digital ceiling.

I am running McDSP Analog Channel on my mix buss these days as well. Helps "soak" any overshoots (that wouldn't clip) and give it that nice analogy flavor (when appropriate).