Using a VU meter plugin for proper gain staging

[DuX]

How I mix regarding audio levels is really simple and that's how they did it in the "old days" [not so old for me ]. I watch that RMS levels on my channels never exceed -18dBFS RMS [setup as VU meter - 300ms averaging], so I have a VU meter/fader plugin running on most channels, and that's it. I don't use my DAW's meters much, just to check those digital peak levels. My finished mixes usually end up as K-14-ish anyway, and no peaks go all the way to 0dBFS ever. It feels good to have enough headroom and no need to worry about those peaks, and the mixes do sound more natural and just - nice. They're also easier to adjust in mastering later on, due to additional headroom, and easier to master in general.

Cheers!

[Fred_Abstract]

in the end it all come down to know your tools, there is really no rules, many artists have great mix using very hot level and sometimes with their 2buss full of processing, just trust your ears and nothing else.
remember the less needed at mastering the best the mix is, also if you are aiming for loud track, you have to think aabout it from the first sound in the daw..getting good mix wiht loudness potential you have way more option to do it in the mix than a mastering enginner with a stereo file

[DuX]

If you're referring to Metallica, Fred, then I agree. Regarding levels.

And I absolutely agree regarding using ears, and doing the best mix possible, YES!

[Fred_Abstract]

lol no i don't know their recent work..but i m thinking to some electronic music producers. i use low level myself but i know some that get great sound with hot ones , but it s easier to destroy a mix with hot levels , understanding and perefct use of dymnaic is requirerd, thats the reason low level are recomended

[DuX]

At times, I do pretty noisy electronic stuff myself, and you can do it really hot, but still watch that RMS doesn't go above -18dB RMS on the channels. The thing is - you shouldn't push the DA converters so far. They sound their best, represent the sound of the mix best, if you're not pushing them. Therefore I'm all for making hot tracks, but against pushing the master channel into red.

Example: put a limiter or distortion on the kick drum, make it sound hot, but keep the volume at -18dB VU RMS. You get a really hot track, but not on the master channel, so you get lot's of headroom to play with later on.

[TreyM]

Compyfox,

Here is a link to my interface manual.

http://tascam.com/content/downloads/pro ... nual_E.pdf

In it I found this information:

On page 24 it says the Preamps have 16dB of headroom. Am I correct in assuming that means they calibrated the convertors to -16dBFS?

Input level (with knob at min) = -2dBu
Input level (with knob at max) = -58dBu

Or is it actually saying -18dBFS because of the knob min level of -2dBu?

[Compyfox]

Here is a link to my interface manual.

God, this is another prime example for a confusing as sh*t manual. And I was acutally thinking of getting this one for my studio.

On page 24 it says the Preamps have 16dB of headroom. Am I correct in assuming that means they calibrated the convertors to -16dBFS?

Input level (with knob at min) = -2dBu
Input level (with knob at max) = -58dBu

Or is it actually saying -18dBFS because of the knob min level of -2dBu?

First of all - stop confusing yourself. The manual is non-telling on that behalf (aka: giving no reference) and I guess your only way to find out what the funk is going on, is to grab a Behringer CT100 and measure yourself.

I assume(!!!) that the device:
- has a dBFS headroom limit of -2dBFS (says so on page 8, but not on the tech-info)
- the input levels for both Mic and Line are actually calibrated to -18dBFS (as they should) and the trim/gain knobs are working outside that range of course (I'll get into this in a minue)
- the manual talks about "nominal" level (which is work level). Of course you need to properly level in your signal first.
- the "headroom" of the device is fairly realistic if you setup your input's to +4dBu (which would mean -18dBFS in theory) and you have a 16dBFS headroom, then you're at -2dBFS (which is the upper clipping limit) - again, on the input side! The output offers +24dBu, which would mean a 20dB headroom on the output side. In short, you're save all around from transients (like drums) that can reach up to +12dB.



Now, what's so confusing here:
The labeling of the trim/gain knob. As with Behringer, it's flipped around (-2dBu on minimum and -56dBu on maximum - eh?!). So ignore that nonsense, grab a measurement tool and do your own tests!

In my case, I found out that the Mic and Line Inputs on my old(!) Behringer consoles are also not labeled properly. So I fired a -18dBFS sine signal through it, setup the gain/trim poties and made my markings for the unity gain (faders at 0, gain/trim at +4dBu) and I was good to go. I also fund out that the old Behringer MX2004A's line channels are fixed to -18dBFS (+4dBu), your Tascam should be the same if the trim/gain knob is at 0 position.



What does it tell you (in short):
Your module is calibrated to -18dBFS (hardware nowadays must be calibrated to the EBU standards - but it's mostly not written into manuals). If in doubt, and you want to incorporate hardware, grab a voltage meter (a multi meter) and go over to RhyhtmInMind's blog and measure what's happening on both input and output. If you're working ITB, then -18dBFS is your reference level. A -18dBFS sine signal on the input (line especially) should confirm this in your DAW. If not, mess with the gain/trim knob.

remember the less needed at mastering the best the mix is, also if you are aiming for loud track, you have to think aabout it from the first sound in the daw..

I'm with DuX on this one, that you can still produce a hot (read: loud) track in a -18dBFS calibrated environment. If you know how, and if you use proper gain staging (there we have these two words again).

Else, I agree on the two points that "listening" has a high priority over measreument tools (though measurement tools tell you if you're within parameters) and that a proper mixed track has a better result while mastering. The old "sh*t in, sh*t out" rule.

[dreamkeeper]

- has a dBFS headroom limit of -2dBFS (says so on page 8, but not on the tech-info)

I'd be reluctant to read "red indicator light" as "dBFS headroom limit". Certainly wouldn't I read it as "upper clipping limit", which wouldn't make sense at all.

Now, what's so confusing here:
The labeling of the trim/gain knob. As with Behringer, it's flipped around (-2dBu on minimum and -56dBu on maximum - eh?!). So ignore that nonsense, grab a measurement tool and do your own tests!

I think you misunderstood that one. Imho it says that IF the input level is at -2dBu, you set the gain knob to minimum. And IF the input level is at -58dBu, you set it to maximum.

Lower input signal --> more gain needed

Makes sense to me. (There IS however a typo on page 8 where it says "+42dBu", which must be "-42dBu" - it's correct in the specs)

[Compyfox]

I'd be reluctant to read "red indicator light" as "dBFS headroom limit". Certainly wouldn't I read it as "upper clipping limit", which wouldn't make sense at all.

Actually, in the manual it's written:
"However, if the signal level exceeds -2dBFS, the indicators will light red".

For me as engineer, that'S a definite no-go area and I put it on the same level as clipping. Granted, you have to have a red indication somewhere - but if it's lighting up, it's dead end.

See it as you like it, but it makes sense with the mentioned headroom in the spec sheet.

I think you misunderstood that one. Imho it says that IF the input level is at -2dBu, you set the gain knob to minimum. And IF the input level is at -58dBu, you set it to maximum.

Lower input signal --> more amplification needed

Makes sense to me. (There IS however a typo on page 8 where it says "+42dBu", which must be "-42dBu" - it's correct in the specs)

Even if it makes sense, it's not(!) written like that. It's clearly written to go from -2dBu to -58dBu, which would indicate an inverted gain/trim knob. Same with the +4dBu to +42dBu. This is not a typo, it's intentional.

Whatever, we can be penny-pinching about this (and every other manual on the market). Fact is, that it's always better to measure and properly calibrate - not only "just in case", but to be sure.


Example:
The Behringer Tube Mic Ultragain 200 is a decent unit and does what it should in terms of DI usage and maybe even MIC preamp. The manual and the markings are utter crap however (read: non telling - essential info is missing!!!!). I plugged a CT100 cable tester in front of it, set it up to run a -18dBFS sine test signal, then calibrated to my needs and actually used a permanent marker to note down where the ideal worklevels reside(!).

While cross checking with my ADC/DAC and Cubase/Wavelab, I got the readouts I wanted (-18dBFS), the units are all calibrated now and I literally threw the manuals into the trash.

[dreamkeeper]

I'd be reluctant to read "red indicator light" as "dBFS headroom limit". Certainly wouldn't I read it as "upper clipping limit", which wouldn't make sense at all.

Actually, in the manual it's written:
"However, if the signal level exceeds -2dBFS, the indicators will light red".

For me as engineer, that'S a definite no-go area and I put it on the same level as clipping. Granted, you have to have a red indication somewhere - but if it's lighting up, it's dead end.

For recording, I wouldn't go that high anyway. It's still not the clipping limit technically, which is 0dBFS for an ADC by definition. Now, a measly 2dB as safety margin... that's a different story anyway.

See it as you like it, but it makes sense with the mentioned headroom in the spec sheet.

Ah, but the 18-2=16 could be just coincidence. To know for sure, one would need to ask the manufacturer directly.

I think you misunderstood that one. Imho it says that IF the input level is at -2dBu, you set the gain knob to minimum. And IF the input level is at -58dBu, you set it to maximum.

Lower input signal --> more amplification needed

Makes sense to me. (There IS however a typo on page 8 where it says "+42dBu", which must be "-42dBu" - it's correct in the specs)

Even if it makes sense, it's not(!) written like that. It's clearly written to go from -2dBu to -58dBu, which would indicate an inverted gain/trim knob. Same with the +4dBu to +42dBu. This is not a typo, it's intentional.

Actually, from the context it seems pretty clear to me - whether it's worded well or not. And if the plus in "+42" isn't a typo, why is it different in the specs listing? Either the former or the latter MUST be a typo, can't be both correct. Everything considered, I'd go with the "+42" being wrong: input signal ranging from -42dBu to +4dBu makes the most sense to me.

Whatever, we can be penny-pinching about this (and every other manual on the market). Fact is, that it's always better to measure and properly calibrate - not only "just in case", but to be sure.

I'm not interested in "penny-pinching". I just pointed out some problems with your interpretation of that manual. After all this is supposed to be a technical discussion, no? So let's be accurate at least with the information available.

[Compyfox]

For recording, I wouldn't go that high anyway. It's still not the clipping limit technically, which is 0dBFS for an ADC by definition. Now, a measly 2dB as safety margin... that's a different story anyway.

Agreed to both. Hence the -18dBFS worklevel. But the main question by the OP was, if he was right and understood the concept. I think we gave him enough info to get from there.

Ah, but the 18-2=16 could be just coincidence. To know for sure, one would need to ask the manufacturer directly.

Indeed.

Actually, from the context it seems pretty clear to me - whether it's worded well or not. And if the plus in "+42" isn't a typo, why is it different in the specs listing? Either the former or the latter MUST be a typo, can't be both correct. Everything considered, I'd go with the "+42" being wrong: input signal ranging from -42dBu to +4dBu makes the most sense to me.

Agreed. Like I earlier said - most manuals are just plain crap - which is why I measure my hardware (and software) regardless. I don't trust certain developers anymore.

I'm not interested in "penny-pinching". I just pointed out some problems with your interpretation of that manual. After all this is supposed to be a technical discussion, no? So let's be accurate at least with the information available.

It's still a theoretical topic.
But else, yes. Different viewpoints on the same topic (technical data of the used hardware).

[dreamkeeper]

Yeah, if you know what you're doing, then measuring is of course the best option.


(sorry for German - I just have to...)

"Wer mißt, mißt Mist." - Alte Technikerweisheit

[TreyM]

It would seem I need to grab that Behringer test unit. Until then, I'm sure I'm safe to assume -18dbFS though. The 16db of headroom thing seems to have no reference as Compyfox stated, confusing matters further than they should.

Speaking of your possibly buying this interface? The preamps are decent enough. For a USB unit this thing has impressed me with it's i/o capabilities. But the very fact that it is a USB interface seems to make it eat CPU a bit more than a FW interface. Granted, I'm using an Alienware hackintosh laptop with plenty of balls in my CPU, so it hasn't been a problem. (In Windows or Snow Leo. I do most of my work in Logic Pro 9.)

The only downside? There is only 1 stereo out group in addition to the main stereo out. Monitor out = Output 1-2. Then you have Output 3-4.

The unit truly can do 16 in though. 14 of that is actually analog in. 8 XLR in, 2 (1/4") with +4/-10 switch, and 4 balanced 1/4" in on back with +4/-10 switches. The remaining 2 inputs are digital spdif I believe.

[Compyfox]

"Wer mißt, mißt Mist." - Alte Technikerweisheit

Nya... it's like "Nach Fest kommt ab" - if you don't do it properly.

It would seem I need to grab that Behringer test unit. Until then, I'm sure I'm safe to assume -18dbFS though. The 16db of headroom thing seems to have no reference as Compyfox stated, confusing matters further than they should.

Keep in mind, the Behringer CT100 is mainly a cable test device. It just happens to come with a test signal generator at -18dBFS.

Speaking of your possibly buying this interface?

I was looking for a recording solution years ago that suited my workflow and was future proof. I completely switched to RME.

[faun2500]

If everyone done proper gain staging then I think a lot of modern music would have a lot better mixes.

Gain staging in my DAW is 100% essential for me!