Changes in levels. What's too small to matter?

[David Piper]

When I started out doing mixing, I thought all the magic was in EQ and compression. But nowdays, I'm really appreciating how important it is to really get the right volumes for everything, and I'm automating volumes a lot more through different sections of the song or even just to bring out drum fills or the nuances of a certain instrument.

But what is too small of a change to fuss over? I find myself tweaking my volume envelopes to within half a decibel, and sometimes I think I hear differences to within tenths of a decibel.

I've heard smart engineers say that changes this small are purely psychological, and I've heard other engineers say that they've spent time refining vocal rides to within a tenth of a dB.

Anyone? When you make changes to volume automation, do you have a 'default' value that you work within to start? What's the smallest amount you will bother fussing over before moving on?

[MoreSpaceEcho]

no defaults...1/2db is probably the most (least?) i worry about. but certainly you can hear that.

sometimes in mastering i'll be adjusting eq's by tenths of a db...

[GooberNumber9]

I'll be the first to say if it sounds good it is good and it depends on the mix and the song, etc. I've gotten all fiddly with very small volume changes and I've just gone and done some light compression and left a fader at the best overall level and let the dynamics speak for themselves. I have more fun with the latter approach, but sometimes the mix just calls for more exactitude.

[vvv]

For me, 1/2 a dB is about what I can hear as an engineer, although that kind of change seems as much about what I feel, as a musician.

Did that make sense?

[lee]

i'm right with you.

on the project that i am currently mixing, i find myself juggling between fractions of dBs. the smallest incriment that my machine can adjust is 1/4 decible; sometimes i go back and forth between a quarter dB up and a quarter dB down, wishing that i could get somewhere inbetween. i've found that opening up the attack on the track's compressor (by a tiny incriment) gets me where i want to be.

it might be obsessing, but if it wasn't for such neurotic behavior, humans would never have created the Hubble telescope.

[Shane Michael Rose]

i swing back and forth between a lot of automation and very little.

if im mixing otb, i tend to do a little less.

itb, by nature i use the tools at hand more (automation)

parallel compression especially with vocal groups can help to lessen the need for lots of automation.

as far as tiny moves.... i get worried about hearing automation moves, so i keep it around a db or so when its a delicate passage.

[cgarges]

While I totally agree that when you're really deep into something, a half a dB can sound like a lot, but I'd be willing to bet that most people, after making a half dB adjustment, then leaving the room for ten minutes and coming back to a blind test of which is which, couldn't tell the difference. Now I'm very well aware that half a dB here and a half a dB there adds up to a whole dB, but the older I get, the more tweaking over tiny adjustments like that seems silly to me. Maybe not silly, but... like, I really don't think that the next day, anyone's going to hear it. Be done and move on.

Chris Garges
Charlotte, NC

[@?,*???&?]

SSL makes their automation sensitive to 3/4 dB. A dB exists because that's about the average level increase or decrease the average person can hear.

I have a level exercise for my Ear Training for Recording engineers class. 1 dB is way to little. Students have a difficult time perceiving 2 or 3 dB changes in level. Everything sounds the same to them for the first hour or so of the exercise.

As we dick around for the last several hours of a session doing level rides, what are we doing other than charging the client?

Is the song lost?

Is there a magic general balance we should go for?

Are level rides really only necessary to change dynamic performances?

Lots to wonder.

[MoreSpaceEcho]

As we dick around for the last several hours of a session doing level rides, what are we doing other than charging the client?

depends. i'm trying to make the mix better, generally off the clock. you're probably just charging the client.

Is the song lost?

no silly, it's right there. under the barcode.

Is there a magic general balance we should go for?

dude i just go for good old fashioned, straight up MAGIC.

Are level rides really only necessary to change dynamic performances?

uh...why else would you be riding levels?

Lots to wonder.

as ever.

[GooberNumber9]

A dB exists because that's about the average level increase or decrease the average person can hear.

Not to go all GS on this thread, but this was just too patently ridiculous to let stand.

The bel was originally devised by engineers of the Bell Telephone Laboratories to quantify the reduction in audio level over a 1 mile (approximately 1.6 km) length of standard telephone cable. It was originally called the transmission unit or TU, but was renamed in 1923 or 1924 in honor of the Bell System's founder and telecommunications pioneer Alexander Graham Bell. In many situations, however, the bel proved inconveniently large, so the decibel has become more common.

Speaking now in terms of dB SPL, the minimum discernable changes by the human ear/brain mechanism I've seen in the research that I've reviewed ranged from about 0.5 dB to 3 dB, depending on a number of factors.
In Table 1 we see a collection of studies spanning 60 years. It should be kept in mind that in each case the results were obtained under laboratory-ideal conditions. Even so, we see a range of values from .25 dB to 3 dB. The resultant range is owing to varying methodologies used by the researchers and, of course, the response of the human hearing apparatus to the applied acoustic signals.

Not only that, but those just noticable difference measurements were taken in terms of a single sound changing level. That is a very different situation from changing the relative mix of different sounds. I'm sure a poll of engineers (especially ones with many years under their belts) would reveal a common perception of .25 dB making a difference, and I wouldn't be surprised if many engineers could detect .10 dB differences, depending on the frequency content, etc.

You can have all of the crazy opinions you want and I won't say a thing. Just don't start spouting supposed facts that obviously have no basis in reality or any research to back them up.

[kayagum]

Be done and move on.

I'm of the school that your initial levels are 95%+ the right ones... sort of like your first impulsive guess on a test question is often right.

The longer I work on a mix, the more likely I have to clear the levels and start over. I hate that when it happens!

Fortunately, I don't work with dense mixes, so usually there's only 1 problem track to ride levels.

[vvv]

To clarify, when I talk about actually using .5dB changes, it's in the context of things like relatively un-dynamic keyboard tracks, or especially heavily compressed backing vocals.

Or bass.

[@?,*???&?]

You can have all of the crazy opinions you want and I won't say a thing. Just don't start spouting supposed facts that obviously have no basis in reality or any research to back them up.

First of all, I have no clue what you're talking about.

Secondly, all my information is found and corroborated in several texts.


From 'Practical Recording Techniques' by Bruce and Jenny Bartlett Page 489:

"Audio level is measured in decibels (dB). One dB is the smallest change in level that most people can hear- the just-noticeable difference. Actually, the just-noticeable difference varies from 0.1 dB to about 5dB, depending on the bandwidth, frequency, program material and the individual. But 1 dB is generally accepted as the smallest change in level that most people can detect."



From 'Modern Recording Techniques' by David Miles Huber Page 55:

"A 1-dB change is barely noticeable by most ears."



From 'the Acoustical Foundations of Music' by John Backus Page 95:

"The decibel is thus a unit which corresponds roughly to the amount a sound must be raised in level to be just heard as louder."


Also, information on AT LEAST one Penny and Giles fader can be found here:

http://www.pennyandgiles.com/docGallery/76.PDF

[kdarr]

no defaults...1/2db is probably the most (least?) i worry about. but certainly you can hear that.

sometimes in mastering i'll be adjusting eq's by tenths of a db...

Would that be a centiBel?

[<|>]

[MoreSpaceEcho]

we better ask jeff.