GAIN STRUCTURE
This is what you guys are talking about.
rebel_lion wrote:I run mine out at 0 dB so that I don't have to raise my gain on my mixer thus more headroom.
Nym wrote:^ you are missed.
ya both kinda wrong and right here.
Of course this has nothing to do with each samples gain, that is different to gain out settings. The samples max is determined by the sample rate ect. But the dB out is what we are talking about here instead.
OK dynamic range first. DAC in MPC has its own dynamic range reguardless of what dB setting chosen. Same goes for your mixing desk. SO....
ryssen wrote:Run on 0 dB, will probably utilize the D/A conversion to the fullest. If you use normalized samples and do real dense arrangements with a lot of info in certain frequency areas or use a lot of effects you might run out of headroom indicated by an unpleasant clipping/distortion. If that occurs, switch the master down a notch.
this is an example of GAIN STRUCTURE> Like I said above changing the dB does not change dynamic range at all, just that when signal goes out it is less that many dB to match gain structure of a mixer. The mixer has its own dynamic range and this also has a noise floor, so you are making sure that you use a signal that is well above the noise floor inherent in that dynamic range of the desk, and not clip as well. Simple. Well ok not so simple at all actually, because you guys are getting confused here. Attenuation is not the same as dynamic range.
The Gain structure is what you are talking about, and how it relates to dBu or dBFS, does not matter which right now. There is also the consideration you do not actually understand the difference between dB vs voltage here, so in gain structure it is volts RMS from dB, not sound dBu or dBFS!
Confused yet? so in MPCs case the dynamic range is not changed at all, it remains the same no matter what dB setting chosen, as it is the DAC, filter, and sample rate that determines the dynamic range here. And it does not change. EVER. So it is, in fact, attenuation of the voltage gain output but in dB. ie less 3dB = half the voltage. Trust me you do not want to know the maths as it is two different logs for it to depending on the type of dB/voltage conversion, but generally -3dB is half the voltage and +3dB is twice the voltage....
So Dynamic range is same, it is just less gain which = voltage! You think it as less dynamic range, but it is not really, it is just gain attenuation, that sounds like that cos you turn it up and it does not clip.
Ok, right so what about the gear after MPC and how does the gain attenuation relate to this?
Well that depends on the gear and its IMPEDANCE ! Look at the spec sheet of any gear. go one get ya spec sheet out. Now look at the inputs specifications. It has Ω impedance in ohms (kΩ) usually. Ands also a dB in as well with that number. This is not the dynamic range. This is to do with the voltage and impedance of inputs. It is a fact that most digital gear has a dynamic range set by the DAC, but in practice it is usually less than this because of a whole range of things like noise, sampling freq filter ect. But this is not the gears actual input at all and that is usually less than output to. So in digital gear there will usually still have the voltage (dB) and impedance (kΩ) of the input and this will usually match DACS range giving you the feeling that this is the dynamic range. It is not though as you now know that there is a difference between the machines actual dynamic range and it has nothing to do with the voltage and ohms of the input. When you match them you are setting the gain structure, not changing any dynamic range. But if it is below noise floor, or is clipping at -18dBu (cos that is where it is 0dB usually) Then yes, you are doing it wrong, but it is not about dynamic range really, more you do not know how to set gain structure and so push up noise floor, or clip the hell out of it and get distortion. See? You are not outside your dynamic range.
If you do some math you can figure out the correct voltage to match impedance of input. This is the gain structure, and its best to think it as electricity not sound, cos that is indeed what it is. that is why stuff can sound better if the line is padded. Or why you need a preamp to hear stuff. So you actually have to do the math to match the MPCs output impedance and voltage to the other gears input impedance and voltage to know for sure what dB attenuation is needed in the MPCs settings.
I reckon none of you have figured this equation out and done it, so that is why there is my lecture above...... Go and do the math to match impedance and voltage then you know your proper setting. Only then will you really know.
So dB relates to voltage here not dynamic range.
