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AKASA Pax Mate Acoustic Absorption Mat 7th October 2002 In
the past only one thing mattered to the PC enthusiast – performance. The race
was on to use bigger heatsinks, faster fans and exotic cooling methods. Over
time it seems that people have become more discerning or it could just be that
the days of the 50%+ overclock are gone. Either way people are starting to
realise that their PCs are quite noisy. Those of you with PCs in their bedrooms
leaving them on overnight to download files (now that unmetered dial-up and
broadband are more common) will have got used to an irritating whine or pray
every night for some temporary deafness. There
are several components that can affect the noise your PC makes: Case
– Type of case used or modification made to it. CPU
– Type and speed of fan as well as mounting method. Chipset
– Small cheap fans are often used to reduce cost. PSU
– Major source of noise. Hard
Drive
– High pitched whine although newer fluid bearing ones are very quiet. Case
Fans
– Number and type of fans used for extra ventilation Over
the next few weeks we will be examining each of these areas in turn to show you
how you can eliminate or at least reduce substantially the noise coming from
each of these areas. In examination of case fans we will go into some
aerodynamic theory (no calculators needed) to optimise airflow from entry point
to exhaust point. At the end of the series we will have shown you how to
transform a PC into one that is completely silent (no more noise than ambient
background). Today
we will look at how general noise can be dampened by applying AKASA’s Paxmate
Acoustic matting to a case. The human ear works by having tiny sensitive hairs
in the inner ear that convert vibration (noise) to electrical signals which are
then interpreted by the brain. The acoustic matting works on the same principle
by having fibres of a certain length to correspond to high frequency noises
since these are generally acknowledged to be the most irritating to us. The
fibres absorb these high frequency noises and convert them into vibration, which
in turn is converted to heat when they move against each other. Don’t worry
about the extra heat generated, as it is so slight it can only be detected by
sensitive scientific equipment. You can also reduce the noise escaping from your system by purchasing a good quality sturdy case but for the purposes of this guide we will assume an existing case will be used (a decent case can cost a fair bit whereas the matting will cost about £12 or under $20). So what will you get for your £12? You get four pieces of matting. The two small pieces are for the top and bottom and the large ones for the doors. The top and bottom pieces will easily fit in any case we have but the side pieces may be a bit big for a mini tower case and require some trimming. Before beginning the installation process I would recommend you remove your motherboard and any expansion cards. If you don’t do this you may have some considerable difficulty sliding the bottom mat under the bottom edge of your motherboard as its sticky side is very sticky and hard to get off again once stuck. Another reason for doing this is to allow cleaning of the case to remove any dust. Anyone who has tried to apply sticky tape to a dusty surface will know the benefit of cleaning before hand. Remember to ensure that any cleaned surface is dry before installing the matting. Let’s apply the two small panels first. Before peeling off the covering put the piece in place to see how it fits. In the Cooler Master case above we see that the top of the case does not come off and the bay housing is embedded into it. So using a sharp pair of scissors we cut off enough matting to allow us to fit the mat snugly. Peel and fold back one inch of backing and line it against the back of the case and smooth it into place. Try and get it right first time to avoid having to pull it off repeatedly which weakens the adhesive. Gently peel the backing from under the mat while smoothing the top of the mat with your other hand. Don’t stretch the material, as this will reduce its efficiency. If you got the first bit lined up the rest should not deviate from a straight path – coax it gently back into line if it does deviate. If you removed the top to do this ensure you check before putting the mat in that it will not impede with any case feature or you may have trouble getting it back on if the mat gets in the way. The
above advice is even more important for the sides. Check carefully that the
matting will not prevent you from putting the side doors back in without
applying excessive force. If you have any features in the door like the handles
in the picture above, cut around them carefully before you peel off the backing. At
this point it’s worth mentioning that while the material provided is adequate
for mini and midi tower cases, there is not enough for a full tower. You can
always buy another set but you will be left with the two small pieces. There is
a novel solution, however. All cases have a metal base that the motherboard is
secured upon. Metal reflects noise for reasons which are too complicated to go
into here and usually you can only see the top half/third of the door behind
this metal base so this is the only part of the back door which will absorb
noise. With this knowledge you can cut one of the mats so you have enough
material to cover the main door while having enough on the back door to cover
its visible area. Full tower owners will get the same efficiency as with two
sets of mats without having to pay for a second one. So
how well does it perform? If
we had an oscilloscope and corresponding sensors we could show you a nice graph
of noise against frequency. Unfortunately we do not but we do have two identical
Cooler Master cases and we swapped the panels to compare them. Several witnesses
were asked but the difference is startlingly apparent to anyone. The high
pitched noise was almost gone. The whine from the 4-drive RAID array was
dramatically reduced. The noise from the fans, PSU and chipset was still almost
as loud as before but it had changed in pitch and lost its edge and was just
largely airflow noise. In conclusion, this is no gimmick and does what it says on the box. £12 for peace of mind is money well spent. At the moment AKASA is the only manufacturer of such a product but some other household names will soon join the bandwagon. We will have reviews of these and how they compare to the Paxmate matting when they become available. All trademarks are the property of their respective owners. |
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