Turtlerock Forum

Posted: **Thu Jul 16, 2009 9:09 am**

http://www.abc.net.au/triplej/musicnews/s2624243.htm

Posted: **Thu Jul 16, 2009 6:21 pm**

Since when is 3dB a doubling in loudness ... ?

Posted: **Thu Jul 16, 2009 6:28 pm**

Maybe it should have been recorded in doubly.

Posted: **Thu Jul 16, 2009 6:48 pm**

Does 3dB equate to a "perceived" doubling in volume? (ie: It "sounds" twice as loud)

I've never tested this, but I've heard it before on numerous occasions.

Dave

Posted: **Thu Jul 16, 2009 8:07 pm**

It does in SPL, though in a CD which is already probably maxed out in FS, add another 3 db and all you're going to hear is lots of clipping which is just going to make it sound busted.

Posted: **Thu Jul 16, 2009 8:10 pm**

dBs are a logarhythmic functions (i think thats how u describe em, someone smarter than me chime in please)...the louder shit gets, the perceived change between the increments becomes more apparent....i assume 3dB around the avg 0dB spot would sound pretty noticeable...

Posted: **Thu Jul 16, 2009 8:11 pm**

Something smells AWFUL funny on this one to me.........

Sounds like they may of tried to do a Metallica and it backfired, still good publicity i suppose :P

Posted: **Thu Jul 16, 2009 8:17 pm**

jkhuri44 wrote:dBs are a logarhythmic functions (i think thats how u describe em, someone smarter than me chime in please)...the louder shit gets, the perceived change between the increments becomes more apparent....i assume 3dB around the avg 0dB spot would sound pretty noticeable...

It is a logarithmic scale, for every 3db you add you double the sound pressure level.

IE: Van Halen playing at 130 = severe pain, Van Halen playing at 136db = deaf probably forever.

Posted: **Thu Jul 16, 2009 8:18 pm**

thanks heath for the correction...dont get smart about it though, ur not smarter than me! hahahaha

Posted: **Thu Jul 16, 2009 8:19 pm**

jkhuri44 wrote:thanks heath for the correction...dont get smart about it though, ur not smarter than me! hahahaha

Ha! Hahahaha. :)

Spose I did learn something at audio skool.

Posted: **Thu Jul 16, 2009 8:22 pm**

actually i suppose u are smarter than me...you are a forum super veteran....

...what do you get after ur forum super veteran? "forum massenburg"??

Posted: **Thu Jul 16, 2009 8:44 pm**

Yeah... sound is one of those things.

I was taught:
3dB will double the SPL
6dB will double the amplitude
and 10dB is closer to doubling the perceived loudness.

Posted: **Fri Jul 17, 2009 7:51 am**

jkhuri44 wrote:actually i suppose u are smarter than me...you are a forum super veteran....

...what do you get after ur forum super veteran? "forum massenburg"??

I did'nt know there was any such thing, until I looked above my avatar. :) Rick's forum works in mysterious ways.

Now excuse me while I find a vocal booth to change into my cape and pyjamas.

Posted: **Fri Jul 17, 2009 10:12 am**

heathen wrote:Now excuse me while I find a vocal booth to change into my cape and pyjamas.

I'd like to see that. It should become your new avatar. :-)

I've got a way to go before reaching super status. I'll keep my cape on ice for a while. Jamil is close though.

Cool. I'm hanging with super dudes.

Posted: **Fri Jul 17, 2009 10:20 am**

Hey isn't your forum title and post count inversely proportionate to the amount of work you have on?

Posted: **Fri Jul 17, 2009 10:41 am**

heathen wrote:
jkhuri44 wrote:actually i suppose u are smarter than me...you are a forum super veteran....

...what do you get after ur forum super veteran? "forum massenburg"??

I did'nt know there was any such thing, until I looked above my avatar. :) Rick's forum works in mysterious ways.

Now excuse me while I find a vocal booth to change into my cape and pyjamas.

I think you become forum super veteran once your post count exceeds 1000.. well, thats what it looks like anyway..

Posted: **Fri Jul 17, 2009 10:43 am**

When Chris Townend's post count exceeds 1000, he'll become a 'massen burger' ;-}

Posted: **Fri Jul 17, 2009 10:46 am**

He better get hunching over the computer then cause he needs a lot more posts. :)

Posted: **Fri Jul 17, 2009 10:50 am**

Hey isn't your forum title and post count inversely proportionate to the amount of work you have on?

nah? im just fast at typing :P

just discovered the other day i can touch type! *loook maaaah...no hands!*

hahahaha!

Posted: **Fri Jul 17, 2009 10:53 am**

jkhuri44 wrote:just discovered the other day i can touch type! *loook maaaah...no hands!

Note to self. Don't touch Jamil's keyboard.

:-)

Posted: **Fri Jul 17, 2009 1:37 pm**

Chinagraf wrote:Hey isn't your forum title and post count inversely proportionate to the amount of work you have on?

Well yes it could be. :)

Posted: **Fri Jul 17, 2009 1:39 pm**

tunetown wrote:
heathen wrote:Now excuse me while I find a vocal booth to change into my cape and pyjamas.

Cool. I'm hanging with super dudes.

C'mon Pete you already knew that. Though I don't think anyone has more posts than Tim. Heh.

Posted: **Fri Jul 17, 2009 2:06 pm**

Sammas wrote:Yeah... sound is one of those things.

I was taught:
3dB will double the SPL
6dB will double the amplitude
and 10dB is closer to doubling the perceived loudness.

Doubling the sound pressure (in pascals) yields a 6dB increase in sound pressure level dBSPL - 20log(2/1)
Doubling the sound intensity (in watts per unit area) yields a 3dB increase in sound intensity level dBIL - 10log(2/1)
Some texts say 10dB equates to a perceived doubling in loudness, some say 6dB.

heathen wrote:It is a logarithmic scale, for every 3db you add you double the sound pressure level.

Adding 3dB won't double the sound pressure level, ie increasing a sound at 100dBSPL by 3dB will yield 103dBSPL, but this is not a doubling in sound pressure level (dBSPL).

Adding 6dB to a sound at 100dBSPL will yield 106dBSPL and this equates to a doubling in sound pressure but again, not a doubling in sound pressure level (dBSPL).

In your example Heathen,

heathen wrote:IE: Van Halen playing at 130 = severe pain, Van Halen playing at 136db = deaf probably forever.

, the increase by 6dB has doubled the pressure (from approx 63Pa to approx 126Pa).

From DJ's website: The problem occurred when the duplicate was produced, as the software program used for this duplication â€˜doubledâ€™ the sound layers. This resulted in a 3dB increase in the overall sound volume.

The problem (from an acoustician's point of view) is the use of the word 'volume'. 'Perceived loudness' is a better term.

davek wrote:Since when is 3dB a doubling in loudness ... ?

Exactly. Play a track in your DAW, duplicate the track, play them both. You'll see and increase of 6dB.
Does this yield a ' 3dB increase in the overall sound volume', I don't think so, but again there's problems with the terminology.

Sheer Noise wrote:Does 3dB equate to a "perceived" doubling in volume? (ie: It "sounds" twice as loud)

I've never tested this, but I've heard it before on numerous occasions.

Dave

I have read that an increase in 3dB (from say 70dBSPL to 73dBSPL) is the minimum increase in loudness that can be perceived by the average listener. (not us). I'll try and locate my source...

Posted: **Fri Jul 17, 2009 6:15 pm**

This is the reference I was referring to.

The human perception of, for example, sound or light, is, roughly speaking, such that a doubling of actual intensity causes perceived intensity to always increase by the same amount, irrespective of the original level. The decibel's logarithmic scale, in which a doubling of power or intensity always causes an increase of approximately 3 dB, corresponds to this perception.

Anyway Mark I'm sure you've had a text book open more recently than me. :)

Posted: **Wed Aug 12, 2009 10:31 pm**

Sammas wrote:
Yeah... sound is one of those things.

I was taught:
3dB will double the SPL
6dB will double the amplitude
and 10dB is closer to doubling the perceived loudness.

Doubling the sound pressure (in pascals) yields a 6dB increase in sound pressure level dBSPL - 20log(2/1)
Doubling the sound intensity (in watts per unit area) yields a 3dB increase in sound intensity level dBIL - 10log(2/1)
Some texts say 10dB equates to a perceived doubling in loudness, some say 6dB.

heathen wrote:
It is a logarithmic scale, for every 3db you add you double the sound pressure level.

Adding 3dB won't double the sound pressure level, ie increasing a sound at 100dBSPL by 3dB will yield 103dBSPL, but this is not a doubling in sound pressure level (dBSPL).

Adding 6dB to a sound at 100dBSPL will yield 106dBSPL and this equates to a doubling in sound pressure but again, not a doubling in sound pressure level (dBSPL).

In your example Heathen,
heathen wrote:
IE: Van Halen playing at 130 = severe pain, Van Halen playing at 136db = deaf probably forever.
, the increase by 6dB has doubled the pressure (from approx 63Pa to approx 126Pa).

From DJ's website: The problem occurred when the duplicate was produced, as the software program used for this duplication â€˜doubledâ€™ the sound layers. This resulted in a 3dB increase in the overall sound volume.

The problem (from an acoustician's point of view) is the use of the word 'volume'. 'Perceived loudness' is a better term.

davek wrote:
Since when is 3dB a doubling in loudness ... ?

Exactly. Play a track in your DAW, duplicate the track, play them both. You'll see and increase of 6dB.
Does this yield a ' 3dB increase in the overall sound volume', I don't think so, but again there's problems with the terminology.

Sheer Noise wrote:
Does 3dB equate to a "perceived" doubling in volume? (ie: It "sounds" twice as loud)

I've never tested this, but I've heard it before on numerous occasions.

Dave

I have read that an increase in 3dB (from say 70dBSPL to 73dBSPL) is the minimum increase in loudness that can be perceived by the average listener. (not us). I'll try and locate my source...

He he! I used to be able to pull out these kind of factoids, calculations and figures, but these days I just shrug my shoulders and say "I dunno". Like most sound engineers ;-)

Posted: **Wed Aug 12, 2009 10:38 pm**

Play a track in your DAW, duplicate the track, play them both. You'll see and increase of 6dB.
Does this yield a ' 3dB increase in the overall sound volume', I don't think so, but again there's problems with the terminology.

I have noticed certain consoles sum differently... I think it was a crapola JBL mini mixer (came free with two JBL EON powered speakers) that increased 6dB on the meters when two identical mono sources were summed to the stereo buss from two mono channels. Tried on another desk (from memory I think it was a yamaha 01V... digital algorithms of course) and the sum increased by only 3dB. Would be interesting to try it on several desks. Will do when I get bored one day.

Now that was confusing.

Posted: **Wed Aug 12, 2009 10:45 pm**

Double the volatge = +3db. +3db = double the voltage. This is because it is non-linear. So you can imagine how much power an ACDC concert uses!

Posted: **Thu Aug 13, 2009 10:21 am**

Roy wrote:Double the volatge = +3db. +3db = double the voltage. This is because it is non-linear. So you can imagine how much power an ACDC concert uses!

3dB does not equal a doubling in voltage.

Take an initial voltage of 1V - double it, 2V.

Express that ratio of voltages logarithmically (in decibels).

dB = 20x log(2/1) = 6dB

An increase of 3dB = a doubling of "acoustic power, electric power, or any other kind of power" (Everest 2001, p. 27), not voltage.

From The Master Handbook of Acoustics (Everest 2001, p. 27)

"When the decibel is applied to voltage gain, it is a 20-log function. That means if you double the voltage, the decibels increase by 6db" (Rozenblit 1999, p. 34)

Everest, F A 2001, The Master Handbook of Acoustics. McGraw-Hill, Boston.

Rozenblit, B 1999, Audio reality: myths debunked, truths revealed. Viewed 13th August 2009 http://books.google.com.au/books?id=Bl1 ... q=&f=false

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