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altruistic.lemon's picture
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RE: Some new gear, can't say I'm impressed

Surely that's 3 db.

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RE: Some new gear, can't say I'm impressed

chebby wrote:

Given all you say, how can you bear to be here Dave?

What can I say, I am on a mission of enlightenment........ >)

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RE: Some new gear, can't say I'm impressed

altruistic.lemon wrote:
Surely that's 3 db.

Sorry, not quite sure what you are getting at.

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

BigH wrote:

As for speakers its not just about Ohms its about sensitivity as well, a speaker of 86DB will be a lot different from a 90db one, it will be over 2x loudness difference.

Are you serious? I assume you are taking the mick, as I am sure you well know a 4dB difference in level is not remotely twice as loud.

Twice as loud is a subjective measure and generally accepted to require a change of level of roughly 10dB.

 

Is that each speaker, if I turn my amp up 10bd it sounds much more than x2 as loud more like 4x, 3db increase is considerable louder maybe not x2.

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

chebby wrote:

Given all you say, how can you bear to be here Dave?

What can I say, I am on a mission of enlightenment........ >)

So enlighten then.

So far you have mostly alluded to your knowledge and experience rather than actually imparted it.

"We are currently awaiting the loading of our complement of small lemon-soaked paper napkins for your comfort, refreshment and hygiene during the journey."

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RE: Some new gear, can't say I'm impressed

BigH wrote:

davedotco wrote:

BigH wrote:

As for speakers its not just about Ohms its about sensitivity as well, a speaker of 86DB will be a lot different from a 90db one, it will be over 2x loudness difference.

Are you serious? I assume you are taking the mick, as I am sure you well know a 4dB difference in level is not remotely twice as loud.

Twice as loud is a subjective measure and generally accepted to require a change of level of roughly 10dB.

 

Is that each speaker, if I turn my amp up 10bd it sounds much more than x2 as loud more like 4x, 3db increase is considerable louder maybe not x2.

Oh dear.

The physics is quite straight forward, for a playback system to increase the measured level It is producing by 3db it needs to double the output of the amplifier. A 10 db change of measured level requires 10 times the amplifier power.

These are measurable quantities and the simple physical facts. 

Percieved loudness is a subjective quantity that is entirely different, in general a 1db change in measured level is the smallest change that can be perceived as a change in level by a person of average hearing. In a domestic situation, playing music, a 2db change may be required for an average person to hear the change as a difference in volume.

Significantly louder requires a level change of 4-6db, ie up to 4 times the amplifier power and twice as loud needs around a 10db change in level, which in turn requires 10 times the amplifier power.

 

 

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

Significantly louder requires a level change of 4-6db, ie up to 4 times the amplifier power and twice as loud needs around a 10db change in level, which in turn requires 10 times the amplifier power.

 

Is that each speaker?

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RE: Some new gear, can't say I'm impressed

chebby wrote:

davedotco wrote:

chebby wrote:

Given all you say, how can you bear to be here Dave?

What can I say, I am on a mission of enlightenment........ >)

So enlighten then.

So far you have mostly alluded to your knowledge and experience rather than actually imparted it.

Is the previous post more to your liking?

Seriously, it is difficult to know at what level to pitch my explanations at. The range of understanding on this forum is vast, some are quite knowledgeable but many do not have a clue, the complete lack of understanding of the differences between level and loudness being a case in point.

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RE: Some new gear, can't say I'm impressed

BigH wrote:

davedotco wrote:

Significantly louder requires a level change of 4-6db, ie up to 4 times the amplifier power and twice as loud needs around a 10db change in level, which in turn requires 10 times the amplifier power.

 

Is that each speaker?

Is this a wind up? What possible difference does the number of speakers make?

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

Seriously, it is difficult to know at what level to pitch my explanations at. The range of understanding on this forum is vast, some are quite knowledgeable but many do not have a clue, the complete lack of understanding of the differences between level and loudness being a case in point.

I know about power and percieved loudness.

If I turn my amp up 10db it is percieved by me to be much more than x2 loudness. I would say 4 or 5db is 2x as loud. 

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RE: Some new gear, can't say I'm impressed

Looks good to me, BigH. Wikipedia says, in part "A change in power ratio by a factor of 10 is a 10 dB change. A change in power ratio by a factor of two is approximately a  3 dB change" . However, perceived louness is a different matter, as you say but our friendly resident expert thought us not intelligent enough to understand the simple physics he explained in less than adequate detail.

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

Seriously, it is difficult to know at what level to pitch my explanations at.

Don't pitch at any 'level'. 

The best teachers make their audience feel cleverer with a mixture of courtesy, respect and a bit of charisma along with their confidence and command of the subject. They make you want to go away and read more and learn more about it yourself.

Announcing you know more than other people (or highlighting how little they know)  before telling them something is a turn-off.

"We are currently awaiting the loading of our complement of small lemon-soaked paper napkins for your comfort, refreshment and hygiene during the journey."

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RE: Some new gear, can't say I'm impressed

The link here explains things :  http://www.sengpielaudio.com/calculator-levelchange.htm 

Around 6db seems to be the roughly correct figure for a perceived doubling.

Chebby, I think earlier ddc said he was a (I presume) hi fi dealer.

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RE: Some new gear, can't say I'm impressed

BigH wrote:

davedotco wrote:

Seriously, it is difficult to know at what level to pitch my explanations at. The range of understanding on this forum is vast, some are quite knowledgeable but many do not have a clue, the complete lack of understanding of the differences between level and loudness being a case in point.

I know about power and percieved loudness.

If I turn my amp up 10db it is percieved by me to be much more than x2 loudness. I would say 4 or 5db is 2x as loud. 

Sorry bigH but your posts suggest otherwise. I'm not having a go but you are way off the mark in nearly everything you say.

Firstly, how do you know that you have turned up your amplifier by 10db, did you measure the output voltage? The SPL?

Secondly, subjective judgements of loudness are just that, subjective. The equivalence of measured level and perceived loudness is an empirical value, based on substantial testing and statistical analysis.

There are so many variables involved that it makes a nonsense of your observations. All it means is that your amplifier appears to get louder rather quickly, that is about all.

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RE: Some new gear, can't say I'm impressed

davedotco wrote:

 

Sorry bigH but your posts suggest otherwise. I'm not having a go but you are way off the mark in nearly everything you say.

Firstly, how do you know that you have turned up your amplifier by 10db, did you measure the output voltage? The SPL?

Secondly, subjective judgements of loudness are just that, subjective. The equivalence of measured level and perceived loudness is an empirical value, based on substantial testing and statistical analysis.

There are so many variables involved that it makes a nonsense of your observations. All it means is that your amplifier appears to get louder rather quickly, that is about all.

My amp volume goes up in 0.5db steps.

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