"0dB" cooling?!?

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0dB implies that there is no change from the reference sound. -infinite dB would imply that you are decreasing the reference sound by an infinite log base 10 amount, which is not the case here.
So in this case it seems, to me at least, that 0dB is indeed correct as that component doest increase or decrease the intensity of the sound compared to the reference.

Am I right?
 
Your first sentence is correct. Your second sentence is not. It *is* the case here. 0dB is not "no sound". 0dB (SPL) is "a standard sound". 0dBm is the equivalent of a 0.632 Volt peak-to-peak sine wave signal into a 50 Ohm load (1 mW). 0dBW is 1 Watt. etc,

dB is usually for power, so in those terms:
relative power (in dB) = 10*Log(actual power/reference power).
For zero power:
relative power (in dB) = 10*Log(0) = - infinity


Doing it backwards:
actual power = reference power * 10^(relative power (in dB) / 10)

For a relative power of 0dB:
actual power = reference power * 10^0 = reference power.

For a relative power of -infinity dB:
actual power = reference power * 10^(-infinity) = 0.

For sound, dB can also describe pressure. Depending on the reference (pressure or power), 0dB corresponds either to an (rms?) pressure of 0.00002 Pascals or 10^-12 Watts or 10^-12 W/m^2 etc.

0.00002 Pascals corresponds supposedly to the softest sound the average human can hear, but it is not "nothing". By this definition about half of humans could hear it. But maybe "0dB" is marketingspeak for "noone can hear it" (technically not true of a 0dB sound), as opposed to "no sound". If you look at a VU meter or a mixing desk or Cubase or audio software with sliders (measuring electrical signals in dBu here), 0dB is loud. The bottom of the sliders are "- infinity."



0dB implies that there is no change from the reference sound. -infinite dB would imply that you are decreasing the reference sound by an infinite log base 10 amount, which is not the case here.
So in this case it seems, to me at least, that 0dB is indeed correct as that component doest increase or decrease the intensity of the sound compared to the reference.

Am I right?
Click to expand...
 
Good job, you successfully managed to waste however much time to prove a totally irrelevant fact that less then 1% of the population would notice, of which the less then 1% would even care about the small discrepancy.

And I think randomizer put it much better then I could.
 
88% of draft-age people can't find Afghanistan on a map. The fact that they are in the majority doesn't make them any less retarded. If you are a hardware company giving specs for a product in "dB", you should know what a dB is. This is what I'm trying to say.
 
Your first sentence is correct. Your second sentence is not. It *is* the case here. 0dB is not "no sound". 0dB (SPL) is "a standard sound". 0dBm is the equivalent of a 0.632 Volt peak-to-peak sine wave signal into a 50 Ohm load (1 mW). 0dBW is 1 Watt. etc,

dB is usually for power, so in those terms:
relative power (in dB) = 10*Log(actual power/reference power).
For zero power:
relative power (in dB) = 10*Log(0) = - infinity


Doing it backwards:
actual power = reference power * 10^(relative power (in dB) / 10)

For a relative power of 0dB:
actual power = reference power * 10^0 = reference power.

For a relative power of -infinity dB:
actual power = reference power * 10^(-infinity) = 0.

For sound, dB can also describe pressure. Depending on the reference (pressure or power), 0dB corresponds either to an (rms?) pressure of 0.00002 Pascals or 10^-12 Watts or 10^-12 W/m^2 etc.

0.00002 Pascals corresponds supposedly to the softest sound the average human can hear, but it is not "nothing". By this definition about half of humans could hear it. But maybe "0dB" is marketingspeak for "noone can hear it" (technically not true of a 0dB sound), as opposed to "no sound". If you look at a VU meter or a mixing desk or Cubase or audio software with sliders (measuring electrical signals in dBu here), 0dB is loud. The bottom of the sliders are "- infinity."



0dB implies that there is no change from the reference sound. -infinite dB would imply that you are decreasing the reference sound by an infinite log base 10 amount, which is not the case here.
So in this case it seems, to me at least, that 0dB is indeed correct as that component doest increase or decrease the intensity of the sound compared to the reference.

Am I right?
Click to expand...

First a small correction, dBm is 1mW into a 600ohm load not a 50ohm load. This would give a voltage of 0.775V. This is also known as dBv or dBu when dealing with professional audio electronics.

Second, dB can be used to describe any ratio of two numbers. The user just has to specify the reference used and what is being described, ie Sound Pressure level, sound power level, voltage, current, etc.

0 dB SPL (sound pressure level) is what is called the threshold of hearing. It is the softest absolute sound that can be heard. If you have two sound source both producing a sound at the threshold of hearing, 0dB, the total sound pressure level would actually be 6dB SPL. 6dB SPL is twice as loud as 0dB SPL. And 0dB SPL is half as loud as 6dB SPL. As a note, from psycho-acoustics, the perceived doubling or halving of SPL is 10dB.

Here is some reading on sound pressure.
Wiki on Sound Pressure

In this situation, "0dB Cooling" means no added sound to the environment. Using this terminology was most likely a marketing decision not an engineering decision, because saying something has "-infinite Cooling", even though it is the proper terminology, could seem to imply, to the average consumer, that the cooling solution is also a noise canceling device, which is not the case. The companies probably don't want the trouble of confusing their average customers with too much engineering speak.

As for the dB scales on mixing consoles and audio software, the references are different than the reference for dB SPL. -Infinity on a console or software means that none of the input gets transfered to the output, while 0dB means 100% of the input signal gets transfered to the output.

-Infinity dB = 0V while
0dB = 1V for a system referenced to 1V
0dB = 0.775V for a system reference of 0.775V
etc...
 
First, it's puppet marketing. Don't be a puppet, assess the actual technology employed and the inhernant tradeoffs involved.

Passive cooling still requires ambient (chassis) airflow, AND it requires a higher ambient airflow than if it weren't passive. If we were arbitrarily comparing cooling solution X with solution Y, it is easily true that X is better than Y or vice-versa, but we are not really forced to use only one or the other.

The truth is, motherboard manufacturers are idiots. They continually used either moderate sized passive no-heatpiped 'sinks or high RPM fans, instead of the optimal solution which is a larger and thicker fan with very very low RPM and quality bearing which is not only inaudible but far longer lived, cheaper, and allows lower chipset temps without increasing chassis airflow. BOO pathetic motherboard manufacturers, tweakers have known this for years but the problem was really the n00bs who can't understand the problem was never "using a fan" but rather "ineptitude using a fan optimally".

Given a good optimized fan, it will not wear out within the lifespan of the sysytem nor be audible outside of the chassis, without the need for as high a chassis airflow rate. It wouldn't seem like a "new" marketing idea though, so instead we get higher priced parts to offset the marketing delusion.

It's not that I'm against passive cooling, it can be very desirable and certainly some cases with rear 120mm fans can do the job, but rather the marketing that they now have some better alternative when all along all they demonstrate is ignorance in even the simplest of cooling tasks is what is crazy.

Bleh, enough of my rant. When they write 0db, they reasonably mean that in itself there is no noise generated but the heat still has to get out of the case and by a higher airflow rate with passive coolers than if there weren't any.
 
The answer is easy: You're wrong. You can't use the negative decibel method when refering to anything except electronic devices without becomming an arse, and by becomming an arse, you're wrong. Let me put this to you gently...

You're comparing one sound to another. That's nice. But what about actual SPL? ie, SPL in a vacuum.

Nearly every hardware manufacturer using the positive decibel method, ie, no sound is zero SPL. And then go on to measure SPL in decibels.

Even if you're an audiophile you're familiar with positive decibels from S/N ratios.

I don't think anyone could argue you're point like you just did without the intent of deceiving people: It's impossible that you didn't know you were using the wrong base scale.

Even I'm familiar with the two ways of measuring sound, absolute sound and +/- compared to a reference sound, and I'm "just some d00d". Bells work for both, just like the units on Celcius and Kelvin are the same.

And that's basically what you're doing, the same as saying saying "they measured the temperature wrong because absolute zero is -273, not 0" when someone was using the Kelvin scale.

The real problem here is that some companies lie in their noiseless claims. Or maybe you're the real problem.
 
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