On Fri, Jul 12, 2013 at 7:36 PM, Harry van Haaren <harryhaaren(a)gmail.com> wrote: Thinko / typo there.. neither *sample* represents the highest value, the peak is inbetween the *samples*. Sorry!

On 07/12/2013 02:36 PM, Harry van Haaren wrote: I understand that they can exist, but for the waveform to be rendered by the D/A, 3dB over the sample values (in the peake between the samples) seems like an unlikely transient. Further, if the D/A has sufficient headroom (modern good D/A should) I would think it's not really a problem. I still see plenty of mastering engineers normalizing their INCREDIBLY LOUD mixes to 0, and to -.1 So in short, I tend not worry about it. :-)

On Fri, Jul 12, 2013 at 09:34:27PM +0100, Harry van Haaren wrote: This is of course an extreme example. In real life the soup isn't eaten that hot. I use dpl1 as a safety net for most of my work, usually it's set to -0.5 dB as the allowed peak level. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Fri, 2013-07-12 at 16:20 -0400, Ricardus Vincente wrote: And those mixes do sound good ;)? They mix music in a way that I can't stand to listen it. You like to listen to this music? In the past I made many masterings with DAT having a margin of just 0.5, IOW -0.5 dBFS, when recording a live session without limiter even peaks that were > 0 dBFS don't cause audible effects. However, what do the meters show? Full-Scale Sine Wave, then the sine is at 0 dBFS or Full-Scale Square Wave, then the max for the sine should be at -3 dBFS. I really don't know what the meters do display. The sound of DAT recordings with peaks at -6 dBFS or lower -12 dBFS etc. don't sound less good, then recordings with peaks at -3 or 0 dBFS. It's nonsense to take care about "optimized" leveling, there simply should be headroom so that peaks won't reach 0 dBFS or -3 dBFS. As somebody already pointed out, e.g. -20 dBFS, then peaks anyway might reach 0 or -3 dBFS. For the mastering, when we know the peaks we don't need that much headroom, but a peak won't reach always the same level, sometimes it might be at -2.5 dBFS and sometimes at -3 dBFS, so minimal headroom is needed. Even if > 0 dBFS sometimes isn't audible, sometimes it does cause audible effects. Regarding to noise, as Julien already pointed out, the instrument or microphone does cause noise, you won't hear the noise of a good sound card. Julien mentioned the DX7, yes, my DX7 does produce audible noise too, but recording my Matrix-1000 is like recording a soft synth, there isn't noise. FWIW there is a reason that adding noise sometimes does improve the sound quality http://en.wikipedia.org/wiki/Dither : "Usage Dither should be added to any low-amplitude or highly-periodic signal before any quantization or re-quantization process, in order to de-correlate the quantization noise from the input signal and to prevent non-linear behavior (distortion); the lesser the bit depth, the greater the dither must be. The result of the process still yields distortion, but the distortion is of a random nature so the resulting noise is, effectively, de-correlated from the intended signal. Any bit-reduction process should add dither to the waveform before the reduction is performed."

On Fri, 2013-07-12 at 14:59 -0400, Bill Gribble wrote: Oops, that was stupid. 6 dB corresponds to 1 bit, so you lose about 3 bits. Thanks, Bill Gribble

On Fri, Jul 12, 2013 at 02:59:03PM -0400, Bill Gribble wrote: Agreed 100%. With 24 bits you have a lot of headroom, and any 'digital gain' used post-recording won't affect the real S/N ratio at all. A working level of -20 dB RMS FS will preserve the full dynamic range even if you have to boost the signal later. A high end preamp/AD such as the RME Micstasy will have a S/N ratio of around 120 dB maximum when configured for a high level line input. With typical gain settings for e.g. recording an acoustic instrument it will be around 100 dB. Most mic preamps will give you much less, and we're ignoring mic self noise and ambient noise. In many cases the latter will determine the real S/N ratio you can have. If you're recording electronic instruments they and the DI-box will determine the noise floor. It won't be near anything that 20 bits can't handle. Anyway, for music with a restricted dynamic range (that includes almost everything presented/discussed here) this is completely academic. You could record the tracks at -40 dB FS and nobody would notice. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Fri, 2013-07-12 at 20:55 +0200, Julien Claassen wrote: I agree! But it's hard to define "reasonable ranges" Not 0 to 3 dB, but -3 to 0 dBFS ;). For full-scale square -3 dB is headroom, for full-scale sine it's the max, so you should add some headroom, e.g. -6 dBFS or a limiter.