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How much is twice as loud?

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busb's picture
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I was very surprised to read just how much it was! I invite you to guess before googling if you don't already know the (correct?) answer.

It's surely a very subjective measure anyway & a bit like trying to quantify something like "twice as hot". I'd love to know how the equivalent power in either watts or dBs was arrived at!

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abacus's picture
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RE: How much is twice as loud?

The ear processes sound in a logarithmic form not a linear form, therefore volume doubling requires 10 times the power (10db), compared to 2 times the power if it was in a linear form.

Example:

1w = 50db

10w = 60db

100w = 70db

1000w = 80db

Each 10db is a doubling of volume.

Bill

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RE: How much is twice as loud?

I thought it was 3db.

tyranniux42's picture
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RE: How much is twice as loud?

3db is the half power point if memory serves and is often used as a benchmark figure such as for frequency response

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tyranniux42's picture
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RE: How much is twice as loud?

abacus wrote:

The ear processes sound in a logarithmic form not a linear form, therefore volume doubling requires 10 times the power (10db), compared to 2 times the power if it was in a linear form.

Example:

1w = 50db

10w = 60db

100w = 70db

1000w = 80db

Each 10db is a doubling of volume.

Bill

 

10db isn't 10 times power, to double your power it's 6db I think. My degree seems such a long time ago...

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tyranniux42's picture
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RE: How much is twice as loud?

tyranniux42 wrote:

abacus wrote:

The ear processes sound in a logarithmic form not a linear form, therefore volume doubling requires 10 times the power (10db), compared to 2 times the power if it was in a linear form.

Example:

1w = 50db

10w = 60db

100w = 70db

1000w = 80db

Each 10db is a doubling of volume.

Bill

 

10db isn't 10 times power, to double your power it's 6db I think. My degree seems such a long time ago...

 

ive both contradicted my first post which was correct and also incorrectly said you were wrong. 10db is 10 times power. 

 

3db as I stated before is half power and therefore also double power point. 

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tyranniux42's picture
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RE: How much is twice as loud?

tyranniux42 wrote:

abacus wrote:

The ear processes sound in a logarithmic form not a linear form, therefore volume doubling requires 10 times the power (10db), compared to 2 times the power if it was in a linear form.

Example:

1w = 50db

10w = 60db

100w = 70db

1000w = 80db

Each 10db is a doubling of volume.

Bill

 

10db isn't 10 times power, to double your power it's 6db I think. My degree seems such a long time ago...

 

ive both contradicted my first post which was correct and also incorrectly said you were wrong. 10db is 10 times power. 

 

3db as I stated before is half power and therefore also double power point. 

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RE: How much is twice as loud?

My degree(Drunk Were a while ago also. I remember the answer to this question! Units relating to loudness= the "Phon" As in SogoPHONio!

Silly reply to a silly question with all due respects!  Question- What does the rest of my username stand for? Answers on a postcard please.puzzled

Cheers.

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RE: How much is twice as loud?

Silly reply also! Apologies! Business just collapsed( Suicidal) And EDITED!!!

Damn this recession. Angry

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RE: How much is twice as loud?

sogophonio11 wrote:

Silly reply also! Apologies! Business just collapsed( Suicidal) And EDITED!!!

Damn this recession. Angry

Very sorry to hear this.

Coming on here and ranting helps (a little).

 

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RE: How much is twice as loud?

Should be in london now, doing what i know best! OUTSOURCING, what the Fxxx does that mean then? Acolades last week, Pxxx off now!

Ah what the hell, who cares any way. Hundred grand a year to nowt in one easy step. Shock doh! banging head against wall shhh shame on you typing away

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RE: How much is twice as loud?

Thanks Cno. No ranting on here is not the right thing to do really, sorry all embarassed Known about this for a few days now. Still have some silly little contracts with provincial theatre ops. But what really gets me is i was the best sound board man in theatre land! Now it seems, the local soho electronics people can do a cheaper/ better job! Sorry being a little silly now.

Off out with my brother now, finish the beauty, eh job off properly! Am sure this bad patch will pass eventualy?boohoo

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RE: How much is twice as loud?

sogophonio11 wrote:

Thanks Cno. No ranting on here is not the right thing to do really, sorry all embarassed Known about this for a few days now. Still have some silly little contracts with provincial theatre ops. But what really gets me is i was the best sound board man in theatre land! Now it seems, the local soho electronics people can do a cheaper/ better job! Sorry being a little silly now.

Off out with my brother now, finish the beauty, eh job off properly! Am sure this bad patch will pass eventualy?boohoo

Talent usually comes through.......so hang in and things will turn.

 

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sogophonio11's picture
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RE: How much is twice as loud?

What a nice guy you are Cno:) Must go now, night life calling hello or goodbye

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gasolin's picture
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RE: How much is twice as loud?

If you have 2x100 watt,  3db more is 2x200watt 

If one speaker is playing 110 db, adding another one that also plays 110 db will increase the total spl to 116db

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RE: How much is twice as loud?

Oh dear....... Shock

The ear does process SPL in a logarithmic fashion and works roughly like this.

The smallest change in SPL that can be heard by a 'normal' person is 1dB. Many need a 2dB change to be positive and this is with a test signal.

A clearly percieved increase in level on a music signal is probably closer to 3dB, depending on how the test is done.

A 6dB increase in SPL requires a doubling of amplifier power, a 10dB increase requires 10 times the power, OK so far?

 

This has implications. For example, a pair of averagely sensitive speakers, say 89dB (1watt, 1meter) produce roughly that level at a normal listening distance in a normal room, this is loud, a more normal 'serious' listening level is around 79dB, requiring 0.1watt, not very much you might think.

So let us play a quality modern recording with a dynamic range of 60dB, remember a CD has a theoretical 96db range. Assuming the average level is 79dB then the average power required from the system is just 0.1watt. Peak level however is 30dB (half of 60dB) higher, ie 10 x 10 x 10 times higher, 100watts in this case.

So you have some new music, or a new bit of kit and invite a few friends round to show off and you turn it up a bit, another 6dB and we are talking 200watts and that is before you build in anf headroom, a professional system will usually have 3 - 6dB, sometimes more. 

Choose a less sensitive model, a PMC or a small ATC and a 200watt amplifier is barely adequate and if you are having a party, just forget it..... Crying

Quick and dirty admitedly, but it does give you an idea of what power is required to make a hi-fi system work.

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