Topic: MME users ----->

[Chuck]

O db isn't an "over."

[F.O.Bean]

thanks

[marc0789]

Thanks Rust -- good point.  Though I'm still not sure that in our real world application of recording PA systems it matters, though there clearly is a difference in theory.  My understanding is that the point you make only would figure in if the noise floor of our taping system is more than the noise level of the PA system we're trying to record.  (I guess we could talk about recording the whole room, not just the PA stacks, but the noise of the people in the room, the HVAC system, etc would probably still lead to the same conclusion.)  Or perhaps stated differently, if the PA system is only providing 68db of dynamic range, it doesn't matter if we limit our recording system to 84db instead of 96db by pushing our levels.

Also, as you note, I don't believe there is even a theoretical difference in dynamic range in recording at -3dbFS peaks (or even -6db peaks) rather than 0dbFS or 0.5dbFS -- you still use that last bit.  And even less of a difference if you record at 24 bits and dither down to 16 bits.

So anyway, I agree with you on what you said, but I'm still worried that tapers who don't understand this all that well will start pushing the hell out of their levels and getting clipping (thus doing more to reduce the dynamic range).  All to get better dynamic range out of their recorders in theory, even though that given the noise level of the system they are recording -- representing the absolute level of dynamic range that is achievable -- is well within the limitation of their recorders whether at -12db or -6db, let alone -3db.  Bottom line, I still think that a few db's of headroom will make for better recordings, not worse.

makes great sense. I don't go crazy with this. I don't like constantly running with peaks only at -4, I shoot for steady -2 and occasional zeros. I see peeps running way too low or way too hot much of the time. The first time I ever patched, the dood with the rig told me to shoot for -12. Glad I figured out how wrong that was fairly quick.

[Todd R]

but technically, 0db isnt an 'over' right

thats why i hit zero on the v3 at least a few times a show, because thats not an 'over'

It depends on how you define "over".  There is no way a digital system can go over 0dbFS (decibels full scale).  That is, there is no way for something more than zero to be represented digitally.  So generally, a single sample at 0db isn't considered an over.  Beyond that, you need to decide how to define an "over" (given that technically it doesn't exist).  When you get several samples in a row that are at zero, it is assumed that you went "over" (meaning that the recorder would have shown a signal greater than zero if it were capable). 

I'm almost positive that Grace defines an over as 3 or more 0dbFS samples.  From the V3 manual:  "The “0” LEDS are dual purpose indicators: the “0” LED will illuminate when the signal presented at the A/D converter reaches 0dBFS but will “latch” on when an “OVER” has occurred".  So if your 0db indicator light was lit and had to be cleared with the peak reset button, then yes, you had an "over".

[Todd R]

makes great sense. I don't go crazy with this. I don't like constantly running with peaks only at -4, I shoot for steady -2 and occasional zeros. I see peeps running way too low or way too hot much of the time. The first time I ever patched, the dood with the rig told me to shoot for -12. Glad I figured out how wrong that was fairly quick.

Yep Marc, that's my approach as well.  A few years back I went to Milwaukee's summerfest and only brought the rull rig in the day Widespread played, the other days I just brought a deck to patch with.  At Wilco's set there was only one taper, so I patched out of him.  He ran it to get maximum -12db peaks.  I tried to get him to up the levels a bit, but he insisted that this was how the manual said to record.  It sounded like crap.