Help on ableton meters...

Discussion of music production, audio, equipment and any related topics, either with or without Ableton Live
five_magics
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Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 4:02 am

I don't understand why the -6 db mark isint in the middle of the ableton meter since it represents a signal at 50 percent of the max value ?
Also for example, when the needle of the glue compressor moves by 6 db, am I dividing my signal level by half ?

I know there is something major I am missing out on here... Been reading articles but I can't get this straight.
Many thanks...

Tarekith
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Re: Help on ableton meters...

Post by Tarekith » Sat Nov 07, 2015 7:39 am

WHy do you think -6dB is half the signal? With a 24 bit signal, you have 144dB of dynamic range, much more with 32bit.

Tagor
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Re: Help on ableton meters...

Post by Tagor » Sat Nov 07, 2015 11:53 am

maybe the volumefader of the virtual mixer-software is not untouched ?

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 1:17 pm

Tarekith wrote:WHy do you think -6dB is half the signal? With a 24 bit signal, you have 144dB of dynamic range, much more with 32bit.
From what I understand from the experiment I made (look at the screenshots) :
When I lower the level of my signal by 6dbFs, the level is divided by half.
That would mean that the current that moves my speakers is divided by half. I notice though that the sound doesn't sound at all "half the loudness"...

Image
Image

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 1:23 pm

Tagor wrote:maybe the volumefader of the virtual mixer-software is not untouched ?
I think that I am mixing up the levels as seen on a waveform, and the levels seen on the faders ?
Sorry if I'm slow at this...

Danny_DJ
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Re: Help on ableton meters...

Post by Danny_DJ » Sat Nov 07, 2015 2:20 pm

6dB represents half the voltage of a signal, yes. Psychoacoustically, 10dB is the half. But for faders, nearly no DAW puts -6dB half the way. For waveform displays, that's another story.

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 3:00 pm

Danny_DJ wrote:6dB represents half the voltage of a signal, yes. Psychoacoustically, 10dB is the half. But for faders, nearly no DAW puts -6dB half the way. For waveform displays, that's another story.
Do you mean that the human brain will perceive a sound at 80dbSBPL to be twice as loud as a sound at 70 dBSPL ? 90dB 4 times louder as 70dB and so forth ?

Tarekith
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Re: Help on ableton meters...

Post by Tarekith » Sat Nov 07, 2015 3:57 pm

I am so baffled 8O

This is the unfortunate side-effect of the term decibel being used in different standards and scales I think.

Long story short, acoustically a 6dB reduction tends to equal half of perceived loudness. In your DAW though, it's a measure of peak digital values, and has a scale where 6dB is not that much at all, certainly not half though.

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 4:43 pm

Tarekith wrote:I am so baffled 8O

This is the unfortunate side-effect of the term decibel being used in different standards and scales I think.

Long story short, acoustically a 6dB reduction tends to equal half of perceived loudness. In your DAW though, it's a measure of peak digital values, and has a scale where 6dB is not that much at all, certainly not half though.
Sorry if you are baffled.
In the example below, 6db reduction does divide the signal level by half. I notice also that it doesn't divide the perceived loudness by half.

Suppose we encode our levels in 4bit.
If the max digital level of the first waveform was equal to 1111, the max digital level of the second one would be 0111.

Image
Image

What I don't understand is by what mathematical rule, the db markings are spaced on the ableton meters. They seem linear from 0 to 24, then logarithmic. What does this graduation correspond to ? Is this spacing arbitrary form practicity ?

Image

Tarekith
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Re: Help on ableton meters...

Post by Tarekith » Sat Nov 07, 2015 5:26 pm

You're right, it's more linear at the top part of the scale to show greater detail, since clipping a digital signal can be bad. Not all DAWs do it exactly like this, but a few do something similar for the same reasons.

The gradations are measured in "decibels full scale", dBFS. 0 being the upper limit of a digital signal beyond which you get clipping, the low end being the absolute noise floor of the system. Though is Live's case they only show you down to like -65dBFS.

chrk
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Re: Help on ableton meters...

Post by chrk » Sat Nov 07, 2015 5:50 pm

You can click-drag the divider between the scale/fader and the sends dials. The spacing changes with length.

It feels a lot like the difference between a 60mm and a 100mm fader, and those aren't linear either.
Tarekith wrote: Though is Live's case they only show you down to like -65dBFS.
Below 60 there's a steep curve towards -?

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 5:58 pm

Bonus question :

On the Ableton meter, there is a green dash and a green bar. The dash represents peak level and the bar RMS level right ?
Many thanks...

Image

chrk
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Re: Help on ableton meters...

Post by chrk » Sat Nov 07, 2015 6:17 pm

five_magics wrote:Bonus question :

On the Ableton meter, there is a green dash and a green bar. The dash represents peak level and the bar RMS level right ?
Which Live version are you using?

Before Live 9.5 there was no indication of RMS, it was just the bar for the momentary peak and the dash for a peak hold (no idea how long it held, maybe even 1sec).

Now theres the lower, brighter part of the bar indicating RMS (i could not find out about the integration time), the darker upper part indicates the momentary peaks, and the dash still shows a peak hold.

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 7:06 pm

chrk wrote:
five_magics wrote:Bonus question :

On the Ableton meter, there is a green dash and a green bar. The dash represents peak level and the bar RMS level right ?
Which Live version are you using?

Before Live 9.5 there was no indication of RMS, it was just the bar for the momentary peak and the dash for a peak hold (no idea how long it held, maybe even 1sec).

Now theres the lower, brighter part of the bar indicating RMS (i could not find out about the integration time), the darker upper part indicates the momentary peaks, and the dash still shows a peak hold.
I'm using Live 9.
In the help box it says it indicates RMS and peak. :roll:

five_magics
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Re: Help on ableton meters...

Post by five_magics » Sat Nov 07, 2015 11:41 pm

five_magics wrote:Bonus question :

On the Ableton meter, there is a green dash and a green bar. The dash represents peak level and the bar RMS level right ?
Many thanks...

Image

Is this correct ?

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