Listen to every fan we
sell here in Sidewinder Computers' The Listening Room. All fan sounds were recorded
in MP3 audio format (128kbps bit rate; 44.1kHz sample rate) and are ranked by apparent
loudness. To hear them, you must have an MP3 player installed, such as Winamp, Sonique,
Musicmatch and others.
For high-bandwidth users (cable/DSL), click the green
Play button in the chart below to hear streaming MP3 audio in your player. For
low-bandwidth users (dial-up), click the red Save button to store each sound file onto
your Desktop for trouble-free playback.
Or, click here
to download all the fan sounds in The
Listening Room Sound Pack (7.10 MB). All the sounds are neatly organized by their
rankings and fan names.
Check out A
Primer in Digital Audio and Recording below for a closer look at the making of The
8. Papst 60mm is sold only with
11. Thermaltake 60mm (TT6025-A) was previously named Volcano II 60mm (F126025BH).
At the time of our initial testing, this fan was only available with the heat sink. Test
shown reflects fan recording while attached to the heat sink. We believe this accounts for
some additional noise/turbulence.
18. The Specifications of the Sunon 80mm high speed have changed
slightly since the publishing of the Listening Room. The new
specifications are 39.5 CFM, 33 dBA and 3000 RPM.
21. We no longer actively stock the
Thermoengine. For this fan, the RPM,
CFM and dBA ratings shown are manufacturer's estimates noted by a tilde ("~")
before the number. However, Sidewinder's The Listening Room tests measured
the fan's apparent loudness as exactly -34.1 dBV, earning it the 21st spot on our chart.
A Primer in Digital Audio and Recording
The loudness of audio is commonly measured in decibel units (dB), and it is even
sometimes measured in units such as Pascals, microbars, or dynes/cm2. But for
this discussion, well stick to decibels.
In general, a decibel is a unit for expressing the ratio of the magnitudes of two
electric voltages or currents. For the purpose of measuring sound, a decibel is equal to
20 times the common logarithm of the voltage or current ratio.
How does this apply to the sounds we hear? We will look at two ways the
intensity of sound can be measured.
The intensity of continuous, audible sound is measured in decibels with a Sound
Pressure Level (SPL) meter, and often, the results are weighted on a scale that takes into
account the typical human ear response. Above, you will see the manufacturers
"dBA" readings, meaning that the results have been weighted on the A-scale. The
A-weighted scale reduces the frequency response of an SPL meter to the 500 to 10,000 Hz
range - the frequency range to which our ears are most sensitive. This gives us a better
idea of the loudness of the fan when we hear it. You may have seen similar scales that
show the sound of a whisper rated at 20 dB; a vacuum cleaner rated at 70 dB; and a jet
engine at take-off rated at 110 dB.
For other uses, the B-weighted scale (dBB) allows the SPL meter to "hear"
lower frequencies down to 32 Hz, and expands up to 10,000 Hz, while the C-weighted scale
(dBC) opens the meter up to all audible frequencies from 20 to 20,000 Hz and is commonly
used to measure the intensity of high-fidelity sound at car stereo competitions.
Another way sounds intensity can be measured is in the voltage output of our
audio equipment, also in decibels. But instead of measuring the SPL with a meter,
we will measure volts in terms of dB, or rather, dBV.
You may have seen these levels on your cassette deck or stereo system indicated in dB,
with the optimal settings at 0 dB. Oftentimes, especially for analog equipment, you will
see the readings exceed 0 dB ("in the red"), meaning that the voltage level
output is something greater than 1 volt. Therefore, we can say that our analog equipment
has a certain degree of "headroom" that can accommodate signal levels over 1
volt. Overdriven signal levels of +1 dB or higher begin to take on a different, sometimes
pleasing, sonic characteristic, and are a way of achieving natural audio compression in
recordings, as the source materials amplitude gently pushes the equipments
limits of reproduction.
In contrast, if you are at all familiar with digital recordings or equipment, you will
know that the maximum sample amplitude we can record is 0 dB, or 1 volt - and nothing
more. The absence of sound has 0 voltage and is noted like this: -
Unlike with analog, if you try to record input levels higher than 0 dB on digital
equipment, the result is "clipping" of the audio signal where the peaks are
flattened so that they will go no higher than 0 dB. Clipped digital audio tends to have a
harsh, unnatural sound.
A "line-level" source signal from our stereo, CD player, or sound card,
measures approximately 1 volt, or 0 dBV. Anything less than 1 volt is shown as a negative
value dBV. For example, -75 dBV is equal to 0.00018 volts.
Why not express levels in terms of volts? Well, because of the great difference between
0 dBV and -75dBV and expressing it in hundred-thousandths of a volt, its easier to
compare terms of dBV than to talk about the difference being 0.99982 volts.
Now that we have discussed two ways the intensity of sound can be measured, take a look
at the manufacturers dBA ratings and our own dBV ratings found in the columns above.
There is no "right" or "wrong" way to display the results, but we
thought to show you two ways.
In general, use the dBA ratings to give you an idea how the noise level compares
perhaps with a whisper (20 dB) or a person talking (in the 40-60 dB range). Use the dBV
ratings for comparative purposes, for example, to see exactly how much quieter a Sunon
120x25 rates to a Sanyo Denki 80x32 - yet pushes 16 more cubic feet of air per minute!
The manufacturers dBA ratings were taken using SPL meter equipment, while the
Sidewinder ratings were taken directly from the sound samples you hear and are measured in
dBV, or the voltage your own sound card is making as you hear them! We tried our best to
"put you there" as if you were standing right next to the fan as we powered it
on, in order to give you a better idea of how its going to sound before you buy.
Our fans were recorded without the heat sinks attached, so what youre hearing is
the fan all by itself. During our tests we found that different makes of heat sinks make
sounds of varying loudness based on how the air is blowing off of them. And, when you try
each fan on every heat sink, you start to get hundreds of combinations for fans and heat
sinks. To keep The Listening Room simple and to the point, we recorded only the
fans for you in our testing lab.
We hope this helps you find the cooling solution which best satisfies your needs. Send
us your comments on The Listening Room to firstname.lastname@example.org.