Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > NZ Computing > KB v Kb

Reply
Thread Tools

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.
 
Reply With Quote
 
 
 
 
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 =----
 
Reply With Quote
 
 
 
 
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
thrad out of it missery.

--
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 =----
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off




Advertisments