Velocity Reviews > KB v Kb

# KB v Kb

Lawrence DčOliveiro
Guest
Posts: n/a

 03-11-2005
In article <42308d00\$1_1@127.0.0.1>,
Robert Cooze <(E-Mail Removed)> wrote:

>Lawrence DčOliveiro wrote:
>> In article <422f3a1c\$1_2@127.0.0.1>,
>> Robert Cooze <(E-Mail Removed)> wrote:
>>
>>
>>>Lawrence DčOliveiro wrote:
>>>
>>>>In article <(E-Mail Removed)>,
>>>> Roger Johnstone <(E-Mail Removed)> wrote:
>>>>
>>>>>Traditionally b for bit and B for byte, but alas a lot of people are
>>>>>ignorant of this tradition. And it is only tradition as these units and
>>>>>abbreviations have never been officially adopted by any standards body
>>>>>as far as know.
>>>>
>>>>Particularly since "B" already has a an official meaning in SI, as the
>>>>abbreviation for the "bel", the unit of ratio. 1 B = 1 bel = a ratio of
>>>>10/1, 2 bels = 100/1 etc (it's logarithmic). A decibel (dB) is one-tenth
>>>>of a bel, which is a ratio of about 1.26. Coincidentally, a change in
>>>>sound output power of that ratio is about the smallest that the human
>>>>ear can detect.
>>>
>>>Depending on the actual thing being measured what I lurned at tec and
>>>proved in experements
>>>
>>>A power difference of 3dB is a [doubling] of power

>>
>> That's consistent with what I said.
>>
>>>ie if your source was produsing 500mW of power (0.5W) and was dobled to
>>>1W A human dould decet the difference of the physical output this could
>>>be light, heat or sound. The point is 3dB is the smallest change up or
>>>down that we can notice.

>>
>> No, for sound it is 1dB.
>>
>> For light it seems to be 4dB. This is the ratio between successive
>> integer steps on the astronomical stellar magnitude scale.
>>
>> By the way, Wikipedia says the "bel" is not an official SI unit. So "B"
>> could still be used for "byte"...

>I was working form a pure electrical eletronics point of view 3dB of
>signal gain = doubling of power...

Actually that's closer to 3.01dB for a doubling. Log10(2) = 0.3010 to 4
figures.

>...sound or light tranmition from a single point like a light bulb or
>single speaker is somthing like a to a power of 3 loss the further away
>you travel away from it...

Power of 2 -- inverse-square law for a point emitter. Inverse-cube would
apply to a dipole emitter.

>...where a flat pannel or tube of light is much
>less lossy ( talking about elexctrostatic speakers and flurenent tubes )

That would be inverse-law (power of 1) for a linear emitter of infinite
length.

>what I was trying to say that the dB in its self is normaly nonsencical
>without [qualification]

It's a ratio. That's all I've used it for above.

Robert Cooze
Guest
Posts: n/a

 03-11-2005
Shane (aka froggy) wrote:
> On Thu, 10 Mar 2005 11:02:51 +1300, AD. wrote:
>
>
>>On Thu, 10 Mar 2005 06:59:36 +1300, Robert Cooze wrote:
>>
>>
>>>p.s. and just to confuse you also in the physical world
>>>
>>>mass X distance = workdone (power)

>>
>>Work and power aren't the same thing. Power is the rate of doing work.
>>
>>Or at least that's how I remember it

>
>
> power is the ability to make others do the work

In a Political sence Too True... ROTFL

--
http://cooze.co.nz home of the RecyclerMan aka Robert Cooze

/ __/ / / / / /__ / / ___/ / __/ / / / |/ / /__ /
/ / / /_/ / / /_/ / _-' / __/ / / / /_/ / / /| / _-'
___\ ____/ ____/ /___/ /____/ /_/ ___\ ____/ /_/ /_/ |_/ /___/

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Robert Cooze
Guest
Posts: n/a

 03-11-2005
Lawrence DčOliveiro wrote:

> In article <42308d00\$1_1@127.0.0.1>,
> Robert Cooze <(E-Mail Removed)> wrote:
>
>
>>Lawrence DčOliveiro wrote:
>>
>>>In article <422f3a1c\$1_2@127.0.0.1>,
>>> Robert Cooze <(E-Mail Removed)> wrote:
>>>
>>>
>>>
>>>>Lawrence DčOliveiro wrote:
>>>>
>>>>
>>>>>In article <(E-Mail Removed)>,
>>>>>Roger Johnstone <(E-Mail Removed)> wrote:
>>>>>
>>>>>
>>>>>>Traditionally b for bit and B for byte, but alas a lot of people are
>>>>>>ignorant of this tradition. And it is only tradition as these units and
>>>>>>abbreviations have never been officially adopted by any standards body
>>>>>>as far as know.
>>>>>
>>>>>Particularly since "B" already has a an official meaning in SI, as the
>>>>>abbreviation for the "bel", the unit of ratio. 1 B = 1 bel = a ratio of
>>>>>10/1, 2 bels = 100/1 etc (it's logarithmic). A decibel (dB) is one-tenth
>>>>>of a bel, which is a ratio of about 1.26. Coincidentally, a change in
>>>>>sound output power of that ratio is about the smallest that the human
>>>>>ear can detect.
>>>>
>>>>Depending on the actual thing being measured what I lurned at tec and
>>>>proved in experements
>>>>
>>>>A power difference of 3dB is a [doubling] of power
>>>
>>>That's consistent with what I said.
>>>
>>>
>>>>ie if your source was produsing 500mW of power (0.5W) and was dobled to
>>>>1W A human dould decet the difference of the physical output this could
>>>>be light, heat or sound. The point is 3dB is the smallest change up or
>>>>down that we can notice.
>>>
>>>No, for sound it is 1dB.
>>>
>>>For light it seems to be 4dB. This is the ratio between successive
>>>integer steps on the astronomical stellar magnitude scale.
>>>
>>>By the way, Wikipedia says the "bel" is not an official SI unit. So "B"
>>>could still be used for "byte"...

>>
>>I was working form a pure electrical eletronics point of view 3dB of
>>signal gain = doubling of power...

>
>
> Actually that's closer to 3.01dB for a doubling. Log10(2) = 0.3010 to 4
> figures.
>
>
>>...sound or light tranmition from a single point like a light bulb or
>>single speaker is somthing like a to a power of 3 loss the further away
>>you travel away from it...

>
>
> Power of 2 -- inverse-square law for a point emitter. Inverse-cube would
> apply to a dipole emitter.
>
>
>>...where a flat pannel or tube of light is much
>>less lossy ( talking about elexctrostatic speakers and flurenent tubes )

>
>
> That would be inverse-law (power of 1) for a linear emitter of infinite
> length.
>
>
>>what I was trying to say that the dB in its self is normaly nonsencical
>>without [qualification]

>
>
> It's a ratio. That's all I've used it for above.

Thats True

I think from my crustry memory if we were using db to measure sound 1dB
is about the quietest a normal average Human cah hear 100dB is getting
very loud and 120dB is where the pain starts. So In my orignal arguments
with the 3dB using electrical ratio's I should be right but in your
orignal posting about sound you are correct. Proberly time to put the

--
http://cooze.co.nz home of the RecyclerMan aka Robert Cooze

/ __/ / / / / /__ / / ___/ / __/ / / / |/ / /__ /
/ / / /_/ / / /_/ / _-' / __/ / / / /_/ / / /| / _-'
___\ ____/ ____/ /___/ /____/ /_/ ___\ ____/ /_/ /_/ |_/ /___/

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----