Solved -10 or +4

[mshilarious]

dBu is referenced as 0dBu = 0.775 volts RMS into an unloaded (open) circuit.

Well, since Lionel is not here to say it for me, the reason dBu is calibrated to 0.775V, a seemingly random number, is because an even older standard, dBm, is calibrated to 1mW power into a 600 ohm load. That happens to be 0.775V (0.775^2/600). It's leftover from the days when gear was designed to transfer power between 600 ohm loads. These days ("these days" being the last 30 or 40 years), gear is designed to transfer voltage, which means bridging loads, or low output impedance, high input impedance.

So you take the same reference voltage, and say it's "unloaded" (meaning high input impedance, which presents a trivial load), and just for good fun, ramp it up 4dB to +4dBu, which is another seemingly meaningless number in the digital age, 1.233V.

0dBV man, it's only 2dB less . . .

 

[Freudian Slip]

By the way switching to +4 from -10 output on your soundcard while your monitors are turned up is a pretty bad idea
I aaaaaaa...... accidently (ya that's it) did it once apon a time and at hi levels 11db is a pretty big difference

F.S.

 

[omtayslick]

By the way switching to +4 from -10 output on your soundcard while your monitors are turned up is a pretty bad idea
F.S.

Yes. I've had that pleasure too. My inputs seem to work fine with +4 or
-10, even with unbalanced cables. I always thought +4 was for balanced and -10 for unbalanced, but perhaps that is a misconception on my part.

 

[Farview]

But that's why we have USB mics now.

That just means that you don't have to know anything about gain structure. The people who design it still do.

 

[pipelineaudio]

as mshillarious alluded to, the entire operating level concept includes as part of the definition "headroom".

There is no strict anysuchthing as headroom in digital, it can be wherever you want it as long as its under zero dbfs

Clown college teaches that anything not peaking (or maybe under -0.3dbfs) is bad. Add up that many ADC and DAC therefore put "0" at +12, +15 or +18 compared to most analog gear and we have a SERIOUS problem with the old paradigm

 

[SouthSIDE Glen]

as mshillarious alluded to, the entire operating level concept includes as part of the definition "headroom".

There is no strict anysuchthing as headroom in digital, it can be wherever you want it as long as its under zero dbfs

Clown college teaches that anything not peaking (or maybe under -0.3dbfs) is bad. Add up that many ADC and DAC therefore put "0" at +12, +15 or +18 compared to most analog gear and we have a SERIOUS problem with the old paradigm

Of course, the fact that clown college is no place to get an education on gain structure notwithstanding , the idea of tracking at 0dBFS as being a good idea is usually the wrong way to look at it, and, if one follows standard analog gain structre procedure, there's plenty of digital headroom.

Send 0VU RMS (give or take) into an ADC and let the ADC do it's job at unity, and one has typically anywhere between 14 and 22dB of digital room for crest factor...the exact value depending upon the exact ADC calibration level. If one needs even more room than that, they can simply throttle back the input to the ADC.

It's still a partial mystery to me why so many owner's manuals still recommend "using every bit". The Usual Suspect excuses of "they're still thinking 16-bit" or "they're trying to make their own gear sound optimal at the expense of downstream operations" just don't really make any sense. I've just resigned myself to the fact that these are the same people who also write stuff like "all your base are belong to us".

G.

 

[Farview]

as mshillarious alluded to, the entire operating level concept includes as part of the definition "headroom".

There is no strict anysuchthing as headroom in digital, it can be wherever you want it as long as its under zero dbfs

Clown college teaches that anything not peaking (or maybe under -0.3dbfs) is bad. Add up that many ADC and DAC therefore put "0" at +12, +15 or +18 compared to most analog gear and we have a SERIOUS problem with the old paradigm

The only serious problem is that now, instead of the old paradigm, you have a population of 'engineers' that don't know how (or why) to calibrate their equipment in order to ensure proper gain structure. The paradigm is fine, the people using the equipment are fucked.

 

[pipelineaudio]

If the people using the gear in this way WERENT fucked in the noggin, radio and pop40 wouldnt sound like dogshit

but it does, and thats the way its now taught and expected to set levels. * Even the clients* know from the magazines where they become OH SO INFORMED that you when you are protoolsing (recording into a DAW), you MUST get the meter all the way to the top.

We havent even gotten to impedance mismatches yet

 

[Farview]

but it does, and thats the way its now taught and expected to set levels. * Even the clients* know from the magazines where they become OH SO INFORMED that you when you are protoolsing (recording into a DAW), you MUST get the meter all the way to the top.

But that's bullshit. It's untrue. It's a myth that is propagated by people who don't understand how the digital world need to interface with the analog world.

One of the reasons you still get manuals that tell you to 'record as hot as you can without clipping' is because the companies writing the manuals are not the ones making the preamps. DA converters don't care about the level, as long as it's under clipping. Neither do DA converters. Most DAWs don't either, you will just have to turn the faders down to keep from clipping the master buss.

For drums and other percussive instruments, recording just under clipping is fine, even a good idea.

For instruments with no attack transient and a long smooth sustain, you will have to boost the signal to +18dbvu to get it up around 0dbfs. That's clearly overdriving the preamp.

 

[eeb]

hrmmm this sounds like it's much more complicated that I thought... I should do more reasearch on this..

when I use my 1010 I usually find that I'm turning everything down more than up.. i'm usually not sitting right down to -10 but definately not at +4. When I try recording at +4 or even a 0 (which btw i'm pretty sure is the "consumer" level on the 1010) i find I have to turn my preamps way down.. almost to 0 and I find the quality suffers alot.. maybe i just don't have things hooked up properly? well another avenue for me to do a bunch of research on is an order.


oh yeah and whoever said that using the faders is useless and doesn't do anything is wrong.. I makes a huge difference.. I couldn't imagine not using it (i don't like having my pre's way too low or too "hot" either so that's where they come in for me) unless that's a terrible practice or something.

 

[Farview]

hrmmm this sounds like it's much more complicated that I thought... I should do more reasearch on this..

when I use my 1010 I usually find that I'm turning everything down more than up.. i'm usually not sitting right down to -10 but definately not at +4. When I try recording at +4 or even a 0 (which btw i'm pretty sure is the "consumer" level on the 1010) i find I have to turn my preamps way down.. almost to 0 and I find the quality suffers alot.. maybe i just don't have things hooked up properly? well another avenue for me to do a bunch of research on is an order.


oh yeah and whoever said that using the faders is useless and doesn't do anything is wrong.. I makes a huge difference.. I couldn't imagine not using it (i don't like having my pre's way too low or too "hot" either so that's where they come in for me) unless that's a terrible practice or something.

If +4 was 'consumer' you would have to turn your preamps up 11db higher than -10.

I think you are confusing a lot of things. Your last post really doesn't make any sense.

Leave the faders on your delta control panel at unity gain (0db)
Leave the faders on the input channel in your software at unity gain (0db)
Looking at the input meter in your software, turn up the gain on your preamp until a sustained note sits around -18dbfs (about half way up the meter)
That's it.

The -10 and 'consumer' thing in the delta panel is for the outputs, not the inputs.

 

[eeb]

no there's seperate controls for output and input. maybe i have the +4 -10 thing confused then hehe but there IS a seperate control of inputs and outputs.. you can turn the levels down.. I find if i leave it at 0 i have to turn my preamps to pretty much 0.. which is why i turn down the inputs..... maybe this is a new feature? but it does exist cause i use it all the time.. (again sorry for my ignorance here I just got this gear and i was used to using the firepod setup so i don't mean to act like i know everything cause obviously i don't )

 

[eeb]

wait i might be completely confusing what we're talking about here heh my bad i think

 

[pipelineaudio]

But that's bullshit. It's untrue. It's a myth that is propagated by people who don't understand how the digital world need to interface with the analog world.

I agree completely, unfortunately, the name for the type of IDIOT described above is "clients"

I know, understand and agree that proper level practices should be maintained, that we should one millenia agree to just where "0" oughtta be (-12,-15,-18 whatever) Im just saying what the modern OH SO INFORMED client expects and what clown college and the recording magazines teach

 

[Farview]

I agree completely, unfortunately, the name for the type of IDIOT described above is "clients"

I have long sense given up on the fight for sane levels on a mastered CDs. The recording levels of the individual tracks aren't ever a point of discussion with me and my clients. If it did come up, I would just use the zoom function to make the waveform look bigger on the screen.

 

[eeb]

HAHAHAH that's brilliant... I should do that

"see the waves are huge!!!" haha

 

[pipelineaudio]

Good trick!

 

[SouthSIDE Glen]

I find if i leave it at 0 i have to turn my preamps to pretty much 0.. which is why i turn down the inputs.....

One thing to double-check, eeb: If your pre is outputting at a line level of +4dBu, meaning that 0VU = +4dBu (as most of them do), and you have the input of your delta set at 0 (BTW 0what? dBu? dBV? Other?) or -10dBV, that could explain much of your level mismatch raght there. You could be running at 0VU on the pre and sending something that could be anywhere from 4 to 12 dB hotter than expected into the delta, which could cause you to be turning down the pre.

G.

 

[Farview]

I find if i leave it at 0 i have to turn my preamps to pretty much 0..

So what? That's what the gain knob is there for, to match the mic input to the line input. It doesn't matter where the knob on the preamp ends up as long as the recording levels are good.


Here is the important part that you really need to wrap your head around:
All the input controls in the delta control panel and your DAW adjust the volume AFTER the converters. In other words, after it is recorded. So turning down the fader on the control panel will not adjust the level that the converters see (the only level that matters). In fact, if you turn that fader down by 10db, you will have to hit the converters 10db too hot (and probalby clip the converters) to get the level you want.

I really don't know why they put those there (on analog inputs, it's usefull for digital sources...kind of)

 

[eeb]

Hrmmm ok I see what you're saying.. I'll take a look.. I just found that when I have them set to 0 it will clip no matter what I do.. so i assumed that these levels are what i needed to use to control that.. i guess i figured it actually controls the converters cause when I turned them down and the pre's up i got a really clean unclipped sound.. and btw i use the gain knobs to adjust the volume and they have to be pretty low too i find. maybe my mixer is just really hot?

is it maybe possible that i'm just turning the volume down and the clipping is less noticable? i don't know.. i thought i had a good grasp on this new gear now i'm not so sure


p.s. btw I didn't mean to steal this thread