Jump to content

Main stereo out peaks at -12, does this cause a problem?


Recommended Posts

Hi All, thanks in advance for you help and advice. I'm just baffled, can't find an answer or any good advice on this specific problem.

 

1) I'm mixing in Logic Pro 9.2 (or what ever the latest version is) - the main output (output 1-2) is set to 0dbfs, and is peaking at -15db and the 2-track 24bit stereo file looks like it has a very "small" wave form.

 

QUESTION: given that the stereo file wave form is "very small", but, the audio sounds like it has enough dynamics - i can see in logic that the meters are pumping up and down... so it's not like it's "an overly compressed" mix but peaking at -15, (there are dynamics in the mix); will this cause problems in the mastering stage? I know that in mastering people want at least 3db headroom, by mix has somehow given me 15db headroom?

 

2) given the "space" and headroom that i have now got, i've slapped an adaptive limiter on it (in waveburner) and yes it makes the master a bit louder BUT no matter what i do, the louder parts of the mix Get Burned? i can hear digital distortion in the cymbals and Hi Freq?

 

QUESTION: I guess the question here is that is the "small wave form" file a problem in this case? should my 24bit stereo file out of logic be peaking higher and have a higher RMS before i even get to mastering?

 

Will strapping a limiter on it, and then pushing that limiter be causing this distortion because there's too much headroom (for a lack of better terminology)?

 

Your help and advice is greatly appreciated.... This mine-field of music production is killing me!

 

Cheers

 

ket :)

Link to comment
Share on other sites

If you want to have it mastered, ask the people who will do it how much headroom they want. I think peaks at -15dB is ok, the mix will still have about 21 effective bits which should be enough.

But if you want to make the mix louder, why don't you set the output fader higher, or insert a "Gain", or add some dB to the channel's faders?

Link to comment
Share on other sites

Hi Jope,

 

thanks for the reply. Well the situation is

 

1) I'm gonna have to master it at home - purely a cost thing, plus i want to learn (so the chances of it being "bob katz" amazing are slim to none)

 

2) I would just crank the faders up in the mix if i could, BUT i've got volume automation and sends all over the shop and this just causes a bit of hassle - purely in that the "mix" sounds good as it is and slight tweaks always cause quite drastic differences (without even being precious with it)

 

4) I was thinking of setting a gain plugin before on the master output but was unsure incase the plugin somehow "adds something (similar to phase) / decreses the master outputs quality?

 

3) I guess my biggest question was really "with the wave file being so small in amplitude - will this cause problems with the mastering?"

 

And from your answer of QUOTE: "the mix will still have about 21 effective bits which should be enough. I take it that the amplitude of the 24bit stereo file does have an adverse affect here? (especially since you calculated the bits somehow - which i have no idea about when it comes to file amplitude and bit depth?)

 

Hmmmmm? what to do?

 

Thanks for the advice, and other advice welcome.

 

Cheers

 

ket

Link to comment
Share on other sites

And from your answer of "the mix will still have about 21 effective bits which should be enough." I take it that the amplitude of the 24bit stereo file does have an adverse affect here? (especially since you calculated the bits somehow - which i have no idea about when it comes to file amplitude and bit depth?)

 

I assume you bounce to a 24bit file (It's the maximum bit depth) to get something that is adequate for mastering. Every bit doubles the dynamic range which means a plus of 6dB (speaking of voltages). If the peaks go up to -12dB, you don't use the two most significant bits (They are still contained in your file, but they don't carry real information).

Be aware there are good reasons why mastering only makes sense if someone else does it... See http://tarekith.com/assets/mastering.html

Link to comment
Share on other sites

Hello guys,

 

just wanted to update anyone for the future as to where i've got with this,

 

1) The MASTER fader (the one to the Right Hand Side of your OUTPUT 1-2 STEREO fader (if you're looking at the entire mixer in Logic) was turned down by a fair whack – I Inherited the arrangement to continue the mix, SO...

 

• This MASTER fader, from a little research, is (as the name suggests) a MASTER for all of Logics outputs.

 

• In my case I'm only using OUTPUTS 1-2, but if I was mixing in surround sound, then outputs 1,2, 3,4, etc are all GLOBALLY controlled by the MASTER fader. and on all those cases, those outputs should not clip (i understand that they do not hold true to the "32 bit floating point" save your arse option. (so arrangement channel strips can clip, but OUTPUT channel strips cannot clip)

 

2) I understand (and please someone correct me if i'm wrong, which i might be)

 

The SIGNAL FLOW IS:

 

• Channel strips (your audio or instrument tracks) > OUTPUT 1-2 (or 1,2,3,4 if surround sound) > Master Fader

 

3) My 24 bit BOUNCED file (to be mastered) was small in amplitude because the MASTER FADER was down, output 1-2, whilst being low, were also compounded by having the master fader down even further…

 

SOLUTION:

• keep master fader at 0dbfs (unless you need to lower all the outputs with a multi channel mixdown)

 

• Do Not Clip the output-1-2 channel strip

 

• To raise the output levels, I did end up raising the faders and having to tweak the automation BUT I could have used a GAIN plugin (under utility>gain) to raise the OUTPUT 1-2 level to a decent output level

 

• A possible concern / negative for me using the Gain plugin on output 1-2 was:

Certain channel strips / faders were way down to -30dbfs, and my concern / reason why I took the time to raise the levels of all faders and sort the automation, was incase this Very Low Fader / level would somehow cause "errors" at that low volume and be somehow lost (digitally) in the bounce-down…. most likely wrong, but thought it best not to take the chance. (anyone care to jump in and lay that question to rest, feel free)

 

Thanks again guys for all your help and advice, and hope that this helps others in the future

 

Regards

 

Ket

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...