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noise to signal ratio?


pampasound

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Hello everybody,

What's the deal with the noise to signal ratio?

The other day i was talking with a post guy and he mentioned recording too low.

I usually record at around -20 to -15 ....is this too low?...he said that when he automate the track in post the noise level comes up as well.

Should i be recording hotter?

It is true that when i listen to the raw tracks in my computer i have to raise the volume quite a bit. Is this normal?

Sorry for my lack of knowledge....i also did search for this topic on the forum but didn't find much....

Thanks in advance,

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ISO tracks typically have more headroom than your mix. Mix levels go all the way up to 0dBFS (without going over). ISO levels I have peak between -20 and -6, no higher.

I would say peaks at -6 are way too hot. I like my isos around the -20 and my mix about 10db hotter.

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Yep, dialog peaks at -10dB for me. Occasional rare peaks a couple of dB above that (slate claps, etc.). And I generally limit the mono mix but not the isos, and leave the isos at least 4-5dB lower than the mix.

Certain shows -- particularly reality shows or low-budget documentaries that are not going to get much finessing for the final mix -- will often complain about production sound being too low, but rarely complain about being too loud, unless there's clipping.

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i use a sd302 with a h4n combo (i know not great but for now i made sure i had a good mixer and mic before a recorder) for my usual set i send boom to R and 2 lavs to L . So if i undestood right, for my boom channel i should be peaking at -10 ...?...and for the lavs mix i should peak at around -20 to -15...?

Does this makes sense?

Thanks to all for your responses!!

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There's more to S/N than levels on your meter.

The mic can be 4 feet too far from the actor, and you can still get enough level. Just turn it up. But the noise and perspective can be bad. Or it can be perfect.

You can record all day at -20, with proper mic placement and top quality mixer/recorder.

But if you have undesirable noise (pre-amp hiss or RF noise or background noise, etc.) at a level too near your desired signal (the voice), then it doesn't matter what level you are recording.

Just record reasonable levels, and use your ears to be sure the bad stuff doesn't creep up on the good stuff.

But for me, I record pretty hot. I think this discussion has been had.

Robert

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A lot of producer/editors are coming up from prosumer production, where -12 dBFS is the nominal tone level for production sound... sacrificing safety to make up for bad mic pres in prosumer cameras. (Some brand-name cameras ALC to -6 dBFS!!)

And they edit on NLEs with linear audio track displays, so stuff recorded at professional levels is less than half as big on their screens.

It's no wonder they think -20 is too quiet.

he said that when he automate the track in post the noise level comes up as well.

That's the scary part. Does he mean his idea of 'automation in post' is to run everything through a compressor?

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" is this too low?... "

yes.

" Sorry for my lack of knowledge "

it is signal to noise ratio... when it is a noise to signal ration, (say in a helicopter) you are screwed!

" Signal to noise is very important in what we do and it's not just... "

plug 'n play !!

Signal = what you are recording --usually dialog.

Noise = everything else.

" tell them to double up on the audio tracks "

doubles the signal, doubles the noise, so s/n ratio = no change.

" sd302 with a h4n combo "

" swarms of newbies borrowing dollars from daddy, buying some gear, asking a few ridiculously rudimentary questions of this forum, and declaring themselves to be "professional sound mixers." "

you need some reading: Jay Rose has some excellent books at www.dplay.com

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No laughs! Too tired. (Long day.)

I think realistically, it isn't too loud if it doesn't clip, and it stays consistent scene to scene and day to day. I only do this with the Mix track. But in doco or reality situations, where I either don't have the luxury of iso tracks or know that there's going to be very little final mixing on the show, I will be a little more aggressive with levels and punch them a little higher -- but with a limiter.

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My take on this is a little different, but on my *very first* project, I had the dreaded "levels are too low" comment... From my professor. Thankfully, this wasn't a paying gig that I borked!

Ever since, my methodology has been to set my cans a little lower (on tone) than most might, which forces me to run levels a bit hotter and still be comfortable in my ears. If a sharp transient like a cough or quick barking laugh "HA!" doesn't light that limiter... You aren't hot enough in levels for general line delivery / conversation over your noise.

I use Sound Devices limiters, which I find to be very smooth and unobtrusive when they aren't being POUNDED at by a truly excessive input. Wendt limiters on something like the ancient X4... Ick. I think I would rather clip. :)

For the newbies who are trying to discover what their limiters might sound like if they are REALLY bashing up against them - Run a song that you are familiar with... (classical music / John Williams stuff is my personal preference, b/c there is LOTS of dynamic range and I VERY well know the sound) Put that through your mixer / recorder with your cans OFF and the mix knob centered. The initial trim level should be enough that the meters peak at -10 or so for this test. Using just the mix knob then, push it up so the limiter is activating solidly and almost constantly. NOW bring up your headphone level and listen to hear the "pumping" and changes to a sound you are familiar with. THAT is what your limiter sounds like when you are mixing way too hot.

Quick transients, fast loud words... These are OK by me to light my limiter, b/c I know they will NEVER be heard audibly as limited.

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