the elusive sound of 0 dB

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Pardon, but I felt compelled share this - a quote from a guitar mart
counter chap.....

"The only reason you ever really need 600 ohm [headphones] is to tell
what 0 dB really sounds like. Sometimes you can't really tell with the
55 ohm ones."

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"SSJVCmag" <ten@nozirev.gamnocssj.com> wrote in message
news:BF446C04.10CD4%ten@nozirev.gamnocssj.com
> On 9/7/05 9:43 AM, in article
> 1126100603.150963.131870@g47g2000cwa.googlegroups.com,
> "apa" <tacoma57@hotmail.com> wrote:
>
>> Pardon, but I felt compelled share this - a quote from a
>> guitar mart counter chap.....
>>
>> "The only reason you ever really need 600 ohm
>> [headphones] is to tell what 0 dB really sounds like.
>> Sometimes you can't really tell with the 55 ohm ones."
>>
>
> Heck... Any good set of earplugs'll get you the sound of
> 0db ...ummm.. Actually what the heck IS a "db"?
> Only thing that comes to mind is 2/3rds of the dbx
> logo....

or which zero dB?

0 dB FS or 0 dB SPL?

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A dB is a tenth of a unit called a Bel named after - guess who? But a whole
Bel is too large and clumsy a unit to handle. It is not absolute in size but
is measured relative to another known level and so its linear range actually
behaves
logarithmically to the ratio (+/-) of a new level and a former level.
1dB is usually accepted as the lowest possible up or down, increment, in
voltage
terms, from a transducer at a mid frequency that can be discerned by human
ear.
Other dBs can be power ratios.

Share this with that counter chap (at least he tried.... to show how to
uphold integrity of, or how to cause a loading effect on, the signal): 0 dB
is only a quotable reference level (at a known line-up freq, of so many rms
volts or millivolts, and at a known impedance) which can be max allowed, or
can be 8 or 10 or 14dB below max - each according to the engineering
institution involved.
The few measurable, fixed standards I know of are 0dBm, 0dBm0, 0dBV, etc.

"apa" <tacoma57@hotmail.com> wrote in message
news:1126100603.150963.131870@g47g2000cwa.googlegroups.com...
> Pardon, but I felt compelled share this - a quote from a guitar mart
> counter chap.....
>
> "The only reason you ever really need 600 ohm [headphones] is to tell
> what 0 dB really sounds like. Sometimes you can't really tell with the
> 55 ohm ones."
>

Archived from groups: rec.audio.pro (More info?)

First show him the sound of one hand clapping.

Then show him half a peace sign.

malachi

"apa" <tacoma57@hotmail.com> wrote in message
news:1126100603.150963.131870@g47g2000cwa.googlegroups.com...
> Pardon, but I felt compelled share this - a quote from a guitar mart
> counter chap.....
>
> "The only reason you ever really need 600 ohm [headphones] is to tell
> what 0 dB really sounds like. Sometimes you can't really tell with the
> 55 ohm ones."
>

Archived from groups: rec.audio.pro (More info?)

On 7 Sep 2005 09:07:12 -0700, "Mike Rivers" <mrivers@d-and-d.com>
wrote:

>
>apa wrote:
>> a quote from a guitar mart counter chap.....
>>
>> "The only reason you ever really need 600 ohm [headphones] is to tell
>> what 0 dB really sounds like. Sometimes you can't really tell with the
>> 55 ohm ones."
>
>The only way you can hear what 0 dB (SPL) sounds like is to get a tube
>preamp, open one of of the vacuum tubes, and get inside.

In space, no one can hear you clip.

Archived from groups: rec.audio.pro (More info?)

On 9/7/05 1:53 PM, in article
1126115638.622412.265620@g44g2000cwa.googlegroups.com, "David Satz"
<DSatz@msn.com> wrote:

> Mike, a practical solid-state alternative for listening to 0 dB is to
> use a short circuit. But the problem then, of course, is that it is so
> short that you have to listen rather quickly.
>
> --best regards
>

(Silly picture of John hopping up and down and clapping enthusiastically
trying NOT to spew coffee...)

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Chris Hornbeck wrote:

> On Wed, 07 Sep 2005 15:52:16 GMT, "Jim Gregory"
> <jim.greg@ntlworld.com> wrote:
>
> >Other dBs can be power ratios.
>
> All dB's are power ratios. A Bel is a power ratio
> of 10.

Avoiding for a second the fact that pro-audio level measurements these
days are made in voltage decibel units ( the dBu ) I'll also point out
that acoustic decibels are *pressure* ratios.

Power ratios ( dBm ) are virtually extinct in pro-audio.

Graham

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Pooh Bear wrote:

> [ ... ] pro-audio level measurements these days are made in
> voltage decibel units ( the dBu ) [ ... ] Power ratios ( dBm )
> are virtually extinct in pro-audio.

?? I thought that the dBu was a measure of how much acoustic power
u hear when a sound reaches u--after it's gone through all the air
between the source and wherever u happen to be located. And dBm is
just the opposite; if I am the sound source, dBm will represent the
acoustic power at my location (where m = "me" ).

The higher the resolution of a concert hall, the more its dBu's
will equal its dBm's. In a place such as Symphony Hall in Boston,
the two numbers will have a very high ratio of equalness between
themselves--100:1 or even more. It's quite hard to beat that.

--best regards

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On 9/7/05 8:43 PM, in article
1126140228.194554.133380@o13g2000cwo.googlegroups.com, "David Satz"
<DSatz@msn.com> wrote:

> Pooh Bear wrote:
>
>> [ ... ] pro-audio level measurements these days are made in
>> voltage decibel units ( the dBu ) [ ... ] Power ratios ( dBm )
>> are virtually extinct in pro-audio.
>
> ?? I thought that the dBu was a measure of how much acoustic power
> u hear when a sound reaches u--after it's gone through all the air
> between the source and wherever u happen to be located. And dBm is
> just the opposite; if I am the sound source, dBm will represent the
> acoustic power at my location (where m = "me" ).
>
> The higher the resolution of a concert hall, the more its dBu's
> will equal its dBm's. In a place such as Symphony Hall in Boston,
> the two numbers will have a very high ratio of equalness between
> themselves--100:1 or even more. It's quite hard to beat that.


(!!! is this guy GOOD , or What!?)

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SSJVCmag <ten@nozirev.gamnocssj.com> wrote:
>
>> (!!! is this guy GOOD , or What!?)

"Chris Hornbeck" <chrishornbeckremovethis@att.net> wrote:>
> Arf!

DOWN Sandy!

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Scott Dorsey wrote:
> Of course. And that's why dBV is the amount of acoustic power in
> a Volvo, while dBC is sound pressure level with respect to that of
> a cat.

Big cat, small cat, hobie cat, or cool cat? (I'll respect any of 'em.)

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Chris Hornbeck wrote:
> On Wed, 07 Sep 2005 15:52:16 GMT, "Jim Gregory"
> <jim.greg@ntlworld.com> wrote:
>
>
>>Other dBs can be power ratios.
>
>
> All dB's are power ratios.

Please let's not go down that road again. :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

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Jim Gregory:

>1dB is usually accepted as the lowest possible up or down, increment, in
>voltage
>terms, from a transducer at a mid frequency that can be discerned by human
>ear.

But thats not true.
You can hear hear smaller streps (0.5dB) compared directly.
And even smaller steps like 0.1dB are hearable, not as a change of
level, but of sound.
Exacly this sound change makes it hard to compare two preamps,
compressors etc.pp.
If they sound actually equal, the one who is a very little bit louder
sounds clearer and more transparent.

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"Mike Rivers"
> Phil Allison wrote:
>
>> If you suddenly became twice as smart as you were before - that would
>> be
>> a 2:1 ratio in IQ.
>
> And if YOU suddenly became twice as smart as you were before, you'd
> really be dangerous.



** Hey - I am more than merely dangerous just as I am.





............. Phil

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On 9/8/05 8:56 AM, in article 3oaqneF532nkU1@individual.net, "Phil Allison"
<philallison@tpg.com.au> wrote:

>
> "Mike Rivers"
>> Phil Allison wrote:
>>
>>> If you suddenly became twice as smart as you were before - that would
>>> be
>>> a 2:1 ratio in IQ.
>>
>> And if YOU suddenly became twice as smart as you were before, you'd
>> really be dangerous.
>
>
>
> ** Hey - I am more than merely dangerous just as I am.

Absolutely.. You're merely annoying too.

This was fun till you peed on the hotdogs...

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SSJVCmag wrote:

> Damn... Phil can't pas up ANY opportunity to piss on ANYBODY's working BBQ
> grille can he?
> Sheeshe..

This is fixable. Let's hotwire the grill.

--
ha

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On 9/8/05 3:40 PM, in article 1h2klua.1h8lxcbrrllhN%walkinay@thegrid.net,
"hank alrich" <walkinay@thegrid.net> wrote:

> SSJVCmag wrote:
>
>> Damn... Phil can't pas up ANY opportunity to piss on ANYBODY's working BBQ
>> grille can he?
>> Sheeshe..
>
> This is fixable. Let's hotwire the grill.

Leave it to you to put things RIGHT back into perspective!

Where'd I put the LOX