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Scythe Silent Box SBX-1000 HDD Enclosure

May 16, 2005 by Devon
Cooke
with Mike Chin

Product
Silent Box SBX-1000
HDD Enclosure
Manufacturer
Scythe
Co., Ltd.
Market Price
US$40

One sign that the computer industry is beginning to pay attention to noise
is the arrival of products targeted specifically at the
silencing market. Fanless power supplies, for example, simply didn't exist in
the consumer market until silence became something the manufacturers could sell.
Hard drive enclosures are another example; although some enclosures have been
sold as cooling devices, their most important function is usually to reduce
noise.

Scythe's Silent Box is just such a silencer-targeted product. Unlike some of
Scythe's other products, the Silent Box is unassuming, both in name and appearance.
But, as they say, looks aren't everything, and if this strange black box is
able to take a bite out of the noise from a whiny or resonant hard drive we're
more than willing to take a look.

SPCR has reviewed a hard drive enclosure before: We examined the Smart
Drive
almost three years ago. We've also looked at a number of do-it-yourself
solutions to hard drive noise, including some homemade enclosures. While these
enclosures tend to be effective at blocking direct noise, they are often less
useful for getting rid of vibration noise that can cause even the quietest drive
in free air to resonate when mounted inside a case. They also tend to act as
insulation; like so many other low-noise techniques, the price of reduced noise
is an increase in heat.

The challenge for the Silent Box will be to reduce vibration as well as blocking
noise, without risking data corruption or drive failure from overheating. To
achieve this, the Silent Box is manufactured from two different kinds of soft
rubber. Its aluminum frame is designed to dissipate heat via a Heatlane. The
Heatlane is a highly efficient version of heatpipe technology, and has been
patented by TS
Heatronics
. We've seen the Heatlane before in other Scythe products,
notably their Zen
series of fanless CPU heatsinks



For once, the product name, not the company logo is the biggest thing
on the box.



Some assembly required ... (Just kidding, we took it apart for the photo).

Feature Highlights of the Scythe Silent Box (from Scythe's web site)

FEATURE & BRIEF COMMENT

Dual Structured Rubber Case

Using NBR (Nitrile Butadiene Rubber) for outer layer and SBR (Styrene
Butadiene Rubber) for inner layer, Silent Box can effectively spread
the vibration
mode to minimize the vibration. Combination of sealed
structure to shut down the noise
from Hard Disk, Silent Box can also
prevent the case noise caused from the transfer of vibration.

An effort is made to deal with both sources of hard drive noise:
Airborne acoustics and vibration.

Powered by Heatlane Technology

Using the famous heat transfer technology from TS Heatronics, the Silent
Box can effectively transfer the heat generated from HDD to outside
of the box.

Transferring
the heat only works if there's somewhere for the heat to go. Hopefully,
the exterior surface of the Silent Box is up to the task...

Compatible up to 10,000 rpm

With the Heatlane technology, the Silent Box can support the HDD up
to the speed of 10,000 rpm
!

Scythe obviously
has confidence in Heatlane technology.

Great Price

Affordable price for such a high quality product!

They wouldn't
say it if it wasn't true ... right?

Scythe has put some thought into a product that addresses
the various aspects of drive noise. The most obvious effect of enclosing a hard
drive is to reduce the direct airborne noise — typically seek and motor
noise — but a major source of hard drive noise is vibration, which is noticeable only when the drive is installed in a case. The interior
of the Silent Box is lined with a soft rubber that is intended to damp these
vibrations. The high mass of the box also has an effect on the vibration
that is transferred to the case.

Scythe has also attempted to deal with the heat buildup that occurs
when a drive is enclosed. The box is supposed to be able to handle 10,000 RPM
drives, so Scythe seems to have confidence in the design. Keep in mind, however, that only IDE HDDs are specified. The only 10K RPM IDE drive we know of is the Western Digital Raptor, which is a single platter drive that runs much cooler than multi-platter large capacity SCSI 10K RPM drives.

SCYTHE SILENT BOX SPECIFICATIONS
Model Number
SBX-1000
Manufacturer
Scythe Co., Ltd.
Compatibility
3.5" IDE HDD up to 10,000 RPM
Dimensions
144 x 211 x 41 mm
Connectors
Ready for Serial & Parallel ATA
Cooling
Heatlane Plate
Material
NB & BR Rubber Case & Aluminum Cover
Weight
840 g

VISUAL ANALYSIS

The Silent Box is visually unimpressive. It's a black rubber box with wires
coming out of one end. There's no bling here; its purpose is strictly utilitarian.



The frame of the box is hard rubber.

The exterior of the box is nitrile butadiene rubber. This is the stuff that
automotive hoses and belts are made of. It is also used to make industrial gaskets
and seals. It is designed to withstand high heat with minimal degradation. In
less technical terms, it's a dense rubber that holds its shape well but is still
pliant enough to flex a bit when we squeeze it. It should do a decent job of
blocking the idle noise from the hard drive, but it's too hard to be of much
use for reducing vibration.



A lining of softer rubber is meant to reduce vibration.

To address the issue of vibration, the inside of the drive is lined with a
softer rubber that is similar in consistency to a spongy Dr. Scholl's insole.
While not as soft as some of the foams we use in the lab (Acoustipack, for example),
it does have some give, and should do more for vibration than the exterior rubber.

When the hard drive is installed, it is surrounded by this softer rubber on
four sides. A half-height block of the softer rubber is also included so that
a notebook drive can be installed without rattling around in the 3.5" space.



The sixth face of the box is also made of hard rubber, and is attached
to the Heatlane that cools the drive.



The Heatlane is folded around the "lid" of the box, and can
be removed.



The "lid" is contoured so that the Heatlane is flush with the
top of the box.

The Heatlane that provides cooling for the drive is attached to the "lid"
of the box, and is designed to transfer heat from the bottom of the drive to
an aluminum frame that holds the box together. The frame is intended to act
as a heatsink for the Heatlane, but its total surface area is only slightly
larger than the top surface of the box. No matter how efficiently the Heatlane
can transfer heat away from the drive, the cooling efficiency of the Silent
Box will ultimately be limited by the amount of heat that can be dissipated
through this surface.

INSTALLATION

The installation procedure is covered in a well illustrated instruction sheet.
Installation has three basic steps: Preparing the drive in the box, screwing
the box together, and installing the box in a case.



Cables must be installed before the box is screwed together.

Once the box has been prepared by arranging the interior rubber lining appropriately,
the drive is placed in the box, PCB up. The drive fits snugly; any empty space
around the drive is filled by the rubber lining.

The power and interface cables must be installed before the drive is installed.
Two six inch cable extensions are included (one that converts the Molex connector
to a SATA connector) so that the box can be separated from the power supply
after it's installed. Unfortunately, no IDE or SATA adapters are included, but
these are less crucial since they can be disconnected from the other end.

Once the hard drive is in place, a thermal pad, or "Gel Sheet", is
placed over the PCB to ensure a proper connection between the drive and the
Heatlane. Two thermal pads are included, but most of the time only one is necessary
to completely cover the internal electronics.



The thermal pads are shipped with a protective layer of plastic that must
be peeled off before use.

The next step is to position the lid and the Heatlane over the drive, and screw
the whole thing together using the aluminum frame.



The Heatlane in position before the aluminum frame is screwed on.

The "elbow" of the Heatlane protrudes beyond the edge of the Silent
Box, immediately above the wires. This makes screwing the frame together a bit
awkward because of the extra height that the cables add to the end dimension
of the case. The problem is worse when using SATA cables, which are thicker
than standard IDE cables. This configuration also adds to the total height of
the box, making it more difficult to slide it into place when it is installed
in a 5.25" bay.



There's not enough clearance to allow the lid to lie flat when a SATA
cable is used.



The aluminum frame holds the box together and acts as a heatsink for the
Heatlane.

Because the body of the Silent Box is rubber, Scythe advises using caution
when tightening the numerous screws so that they do not strip the rubber. We
found that the best technique was to put the lid under pressure and then tighten
the screws while they were not under tension. Two screws on each end of the
box are also used to ensure that the vertical screws do not pop out under tension.
Unfortunately, the additional space required for the cables made it difficult
to align the screw holes on this end of the box.



The screws must be installed gently to avoid stripping the rubber.

Once the box is screwed together, the whole thing is meant to be screwed into a 5.25"
optical bay. The size and material of the box make it quite a tight fit, but
we managed to ease it into place without too much trouble.

TEST RESULTS

The Silent Box was tested against the only other drive enclosure officially reviewed by SPCR: The Smart
Drive
. Each enclosure was tested for effectiveness in reducing airborne
acoustics and vibration, and also for how well it dissipates heat. Two reference
drives were used: The noisiest drive we could find, and the highest
vibration
drive. Each drive was tested in free air according to our
standard hard drive testing methodology
, and then again in each of the enclosures.

Hard drive temperatures were measured using S.M.A.R.T. reporting via SpeedFan
4.23
. The drive was placed in open air on a carpeted surface and allowed
to idle until the temperature stabilized. Typically, it took about an hour and
a half for the temperature to stabilize. Because there was no airflow across
the drives and only a small potential for heat conduction through the carpeted
surface, our test bench conditions may be slightly tougher than an actual case.
However, the ambient temperature during testing was lower than most system temperatures,
so there is also a thermal benefit to our test bench. Our thermal testing is
designed to reveal differences between the different enclosures, and may not
represent the exact thermal performance inside a case.

Ambient conditions during testing were 24°C and 18 dBA/1m.

SMART DRIVE AND SILENT BOX NOISE REDUCTION CHARACTERISTICS
Reference Drive State

Vibration

1-10

(10 = no vibration)

Idle Temperature

Activity State

Airborne Acoustics
Free Air
2
46°C
Idle

31 dBA/1m
Seek

32 dBA/1m
Enclosed in Smart Drive
4
44°C
Idle

25 dBA/1m
Seek

26 dBA/1m
Enclosed in Silent Box
6
42°C
Idle

27 dBA/1m
Seek

28 dBA/1m

The reference drive that we used to evaluate the reduction in airborne acoustics
was the noisiest drive we could find in the lab. Its identity will not be revealed
to protect the innocent. Suffice to say that it has seen over three years of
daily use, and is no longer being manufactured.

Its noise character is best described as a grating metallic whine that cycles
by about 2 dBA/1m in volume. All measurements of the drive were made at the
peak of the cycle. The drive also makes a highly resonant ringing sound that
fades in and out in sync with the cycle of the whine. Seek noise is almost inaudible,
but this is because the idle noise is so loud, not because the seeks are quiet.

Smart Drive, by Grow Up Japan



The Smart Drive is a nicely designed aluminum HDD quieting box.

SPCR's review back in June 2002 admired its precision fit and finish, and the floating aluminum box in box design. The inside box kind of "floats" acoustically in thermally conductive damping foam. (Please read the whole Smart Drive review for full details.)

The Silent Box's DIY Predecessor

They say there's nothing new under the sun. There's also hardly anything new in the quiet PC market that SPCR enthusiasts haven't done already. The Silent Box is a refined echo of a HDD silencing box made from rubber and described in the SPCR article Rubber Boxes & Carved Foam: More HDD Silencing. It was made not from Nitrile Butadiene Rubber but block print carving rubber (for art hobbyists), and there was no heatpipe heatsink nor inner layer of Styrene
Butadiene Rubber, but Leo Quan's rubber box did work, and it preceded Scythe's commercial effort by over two years.

Who can deny the possibility that Leo's Rubber Box could have been the inspiration for Scythe's Silent Box? After all, it's not just consumers who browse SPCR regularly but also many savvy and interested individuals in the industry. (Take a bow, Leo.)

The Smart Drive is most effective for cutting out the biting high frequencies
from the test drive. What's left is a mid-band hum that's about 6 dBA/1m quieter
than the drive in free air. However, it does nothing for the resonant ringing
that now dominates the character of the noise. The drop in volume is substantial;
airborne noise could probably be dropped below ambient with a quieter drive,
although our test drive is merely reduced from "noisy" to "somewhat
quiet". Even enclosed, our reference noisy drive could not get down to the level of
quiet exhibited by modern drives in free air.

Perhaps because of the reduction in idle noise, seeks are more clearly audible
inside the Smart Drive. They sound less sharp than in free air, and cause a
low rumble that was not previously audible. Overall, the quality of seek noise
is an improvement even if they are slightly more audible over the idle noise.

The effect of the Smart Drive on vibration is small, in the realm of 1-2 points
on our scale of vibration. Unless a very low vibration drive is used to begin
with, there is still room for improvement. Only the lowest vibration 3.5"
drives will gain enough damping from the Smart Drive not to benefit further
from suspension mounting.

The Smart Drive is made of aluminum and is designed with heat concerns in mind.
Our test drive saw a modest 2°C drop in the idle temperature when mounted
in the Smart Box. This is not a large improvement, but it does suggest that
it's not going to cook the drive when mounted inside a case. Our thermal reference
requires a small amount of airflow to be safely run in a real system, and this
is still true when mounted inside the Smart Drive.

Silent Box, by Scythe

The acoustic improvement offered by the Silent Box is not as dramatic as for
the Smart Drive. Neither the character nor the volume of our reference drive
improved as much as they did for the Smart Drive. As with the Smart Drive, the
primary character of the noise is a resonant ringing. However, in addition to
this, some of the sharp motor whine still remained, modulated by an odd "throbbing"
quality that may have been hidden under the whine of the motor before it was
installed in the Silent Box. The noise reduction is probably enough to
silence a quieter drive, but some care in drive selection will need to be taken,
as the improvement is not large.

The effect on seek noise was similar to that of the Smart Drive: Seeks became
slightly more audible, but they sounded like a low rumble rather than a sharp
clatter. The rumble may be slightly louder than for the Smart Drive, but it
is still close enough to the idle level that it is not intrusive.

For vibration, the softer rubber lining seems to help. It was very difficult
to judge the magnitude of the improvement, but it seems significant.
The rubber exterior and high weight of the Silent Box made our vibration test
box unreliable, as it had the effect of damping
the box as well as the drive! Based on some tactile observations (holding it in our hands) as well as
an examination of the Silent Box inside a case, we cautiously place the improvement
at around four points. We are unsure of how effective the Silent Box is for
damping lower levels of vibration, but it can probably be mounted in an a optical drive bay with a low vibration 3.5" drive without incurring much cost in vibration-induced noise. Results will depend on your case and what it sits on — something resilient like carpet is better than a hard wood floor, for example.

The Heatlane cooling provided by the Silent Box appeared to wok well, but this improvement may
be artificial because the Heatlane transfers heat from the bottom of
the drive where we suspect the thermal diode is located. As mentioned, the surface
area of the aluminum frame is not large (it's about half the size of the Smart
Drive), so we are unsure of where the Heatlane is transferring the heat to.
Nevertheless, our drive recorded a 4°C drop in temperature inside the Silent
Box. How this translates to thermal performance when installed in a system will depend greatly on system specifics. There will be some conduction of heat through the rubber surface when installed in a 5 1/4" drive bay, but how much this will offset the lack of airflow around the optical bays in a typical case can only be judged in operation in the specific system.

AUDIO RECORDINGS

Audio recordings were made with the reference noisy drive installed
in each enclosure and in free air. They are presented here in MP3 format. The
recording for the reference drive was made according to our
standard drive testing methodology
, and contains 10 seconds of idle noise
followed by 10 seconds each of seek noise with AAM enabled and disabled. Because
our reference drive does not appear to support AAM, this second section of seek
noise was dropped when we recorded the drive inside the enclosures.

Reference
Noisy Drive in Free Air (Idle: 31 dBA/1m / Seek: 32 dBA/1m)

Reference
Noisy Drive inside Smart Drive (Idle: 25 dBA/1m / Seek: 26 dBA/1m)

Reference
Noisy Drive inside Silent Box (Idle: 27 dBA/1m / Seek: 28 dBA/1m)

Comparatives:

Seagate
Barracuda IV ST340016A (Idle: 21 / AAM: 23 / Seek: 25-26 dBA/1m)

Samsung
Spinpoint P80 SP0802N, Nidec Motor (Idle: 21 / AAM: 23-24 / Seek: 25-26 dBA/1m)

Samsung
Spinpoint P80 SP0802N, JVC Motor (Idle: 21 / AAM: 25 / Seek: 27 dBA/1m)

Nexus 92mm
case fan @ 5V (17 dBA/1m) Reference

HOW TO LISTEN & COMPARE

These recordings were made
with a high resolution studio quality digital recording system. The hard
drive was placed on soft foam to isolate the airborne noise that it produces;
recordings do not take into account the vibration noise that hard
drives
produce. The microphone was centered 3" above the top face
of the drive enclosure. The ambient noise during most recordings is 18
dBA or lower.

To set the volume to a realistic level (similar to the
original), try playing the Nexus 92 fan reference recording and
setting the volume so that it is barely audible. Then don't reset the
volume and play the other sound files. Of course, tone controls or other
effects should all be turned off or set to neutral. The accuracy of the reproduced sound will be profoundly affected by the fidelity of your audio playback system. For full details on
how to calibrate your sound system to get the most valid listening comparison,
please see the yellow text box entitled Listen to the Fans
on page four of the article
SPCR's Test / Sound Lab: A Short Tour.

CONCLUSIONS

The Silent Box is a good product for those who have a quiet drive but are seeking
silence, not mere quiet. Those with noisy drives are likely to see a
bigger improvement from upgrading their drive, while most quiet drives will fall
below the noise of even "quiet" fans. The Silent Box is not the first
product you should buy when putting together a quiet system, but it may be one
of the last. In a system where even a quiet drive is
still a major source of noise, the Silent Box may provide that final bit of
noise reduction. Then again, silencers are an obsessive bunch — we
like to tinker with our systems even when we can't hear them!

The Silent Box may also find a niche among those who have a preference for
large capacity drives, which are noisier than lower capacity models. The Silent Box
can bring the noise of these drives down to the level of their smaller, quieter
cousins.

Carefully paired with a low vibration drive, the Silent Box may be useful as
an alternative to drive suspension. Such a drive would need to be reasonably
quiet already, as the reduction in airborne noise is not enough to silence a
loud drive. So long as some care is taken to choose the right drive, the
Silent Box is capable of performing as advertised: A "silent box"
may indeed be a possibility.

In direct comparison with the Smart Drive (and its later variants -- the 2002 model and the copper version), it's not quite as effective on acoustic silencing but better at vibration damping. It offers a somewhat different balance of strengths.

Installation is a bit involved, and the fit isn't perfect, but these flaws
are forgivable if you only need to install one drive one time. On the other hand, our
testing required countless installations, and we got a bit sick of the excessive
care that is required not to strip the screw holes.

Like aftermarket heatsinks, fanless power supplies and high-end cases, the
Silent Box is an enthusiast product: It is designed for the very specific purpose
of damping hard drive noise. It provides a small benefit that cannot be achieved
in any other way, except perhaps by copying Leo Quan's groundbreaking DIY rubber box from a couple years ago. Used properly, the Silent Box makes an excellent addition
to a quiet case, but it is not the place to begin when silencing a computer.

Many thanks to Scythe
USA
for this Silent Box sample.

* * *

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