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0 VU / -18dBFS
Hello!
As a new M-box user I did a search on this forum to see what the best level would be to record at. I found that for the M-box -18dBFS = 0VU. But what does this mean?? I used a 1000hz test tone and set it to 0VU on the BF meter bridge (calibrated to -18). After that I opened my PAZ meter from Waves and I noticed that this 0VU indeed was -18dBFS, but ONLY when the meter was set to 'RMS'. The PEAK level of my 1000Hz tone was somewhere around -14.9.... Is this correct? Does this mean I should record my AVERAGE level at -18dBFS? This means the peaks are much louder.....is that a bad thing? I'm just a little confused!! |
#2
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Re: 0 VU / -18dBFS
Quote:
Quote:
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#3
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Re: 0 VU / -18dBFS
That's exactly waht it means, nominal signal inputs should be targeted for -18dbfs on the M-box. This leave adequate headroom before clipping for transient peaks while maintining optimum audio quality.
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#4
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Re: 0 VU / -18dBFS
Right thanks for the answers!
Quote:
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#5
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Re: 0 VU / -18dBFS
OHHHH, you want me to pull that stuff out...okay, it's the definition of the average of the root of the square. Some would look at this and say, well, the root of the square is just the number...not so. In many cases, just taking the average can result in singularities and zero points, where taking the average of the root of the square does not. I know this must be confusing for a lot of people...it aint easy to describe, so I'll see if I can find some info on the web to gander at for explanation, but suffice it to say this: there is indeed a difference mathematically (in meaning and calculation) between the square root of the average square and the average.
here is basically what an average is and here is RMS I could probably dig up some of my old physics lessons in ps or pdf form if you really want an in-depth explanation of the differences...warning: math ahead, break out the aspirin and the wine!
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#6
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Re: 0 VU / -18dBFS
All Right!, I found a page that should be fairly easy to grasp for anyone (math background or not) that shows how the average and the rms can differ: can be found here.
This one is very simple and should give a good idea of how the two can differ and basically give you an understanding of the concepts even if you don't understand the integral calculus. Hope this helps, -Chris
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#7
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Re: 0 VU / -18dBFS
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#8
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Re: 0 VU / -18dBFS
(I was rather surprised to find a description like this one...you can see all the direct relations to audio... )
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#9
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Re: 0 VU / -18dBFS
Yes...that made it all a little clearer, thanks man!
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#10
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Re: 0 VU / -18dBFS
Okay, so a little homework for you then:
What is the equation for average rms? Ans: <sqrt(<x^2>)> It's different too! (Which is why wavelab has all those different values for RMS...a peak rms, an average rms...etc...)
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