Noise Survival Guide (emergency remedies): pr. 12.09.2001

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Following up the interest on the topic, I've tried to make an overview  based on my experiences sofar.
The Quest for Silence continues on however ...

Note !

Water- and refrigerator-type-cooling is at the moment consideret out of scope for this project.
The focus has been on taking air-based cooling (active and passive ) to the edge before any indepth consideration of  this kind of solution.

Introduction :

Assuming a novice level on the topic. The first thing that you ought to do is to ensure that your system has a "dynamic" noise characteristic. That is that there is a relationship between the noise-level and the system load. If the noise level of your system is constant, the number one step to take is to install a noise-killer of some sort. Without a dynamic operation, the reduction in power-consumption that can be achieced will have no noticable effect on the noise level of your system. Second step : install a software cooler, this will have a dramatic effect on power consumption, and hence the idle/normal operation noise level. Third step : Cabinett dampening / noise box for the HD. Forth step : Doodle around with all the other configurations till you find something that works for you and your system.  See sugestions below.

Note ! Software coolers vs. ACPI : If you are in the absolutely improbable position that you got a system with a ACPI configuration that actually works, software coolers will have little or no effect. Just discovered this when I acidentally got the ACPI stuff "working".

Approaches :

There are different ways of handeling a problem, in this case audiable noise. One is to focus on the problem. The other is to focus on the source of the problem. It's like removing pain with pain-killers, instead of removing the cause of the pain. Of course waking up after a late night at the pub, you might not care about the subtle difference.

Remedies :

Bottom line in these TV times :

Optimize the system to minimize power-consumption and disk access. Optimize the passive airflow through the cabinet and minimize fan speed. Get a silent HD and box it. Trade performance for peace, it's a good deal. Take some risks. Don't worry too much. Silence of the ear is worth more than all the gold in the world, and peace of mind is worth even more than your own life.

Software and system configuration :

- Software Coolers :  CPUIdle(v.5.06 & 3.01), Waterfall, etc (Usefull on system without ACPI)
- HD spinndown
- Disk caching (win95)
- FAT 16/32 issues. More noisy and slower ?
- Other tools (ramdrive, do a search engine o.l.)
- Windows (95/98) configuration.
- APM
- ACPI (Activate if your feeling lucky)

Hardware and physical modifications :

- CPU Fan - Reduce fan speed (by altering voltage from +12V to +5V or +7V), change fan type (higer quality, speed controll, temperature regulated)
- PSU - Add noise killer - Exhaust Muffler - Noise Trap - Change of PSU.
- Cabinet modification : damping [ the carpet method ], suspension (shock absorbing feets).
- Modification of system setup (to minimise power-consumption).
- Memory : Add to minimize disk activity.
- HD - Noise Box / Vibration dampening fram kit of some sort.
- HD - Mode of operation - IDE - ATA - Spinn speed (4400/5400/7500/10000) - Seek IQ   (IBM have released drives where noise is a design factor)

Going futher : Desperation level : 1.more silence :

- Removal/deactivation of equipment (disk drive, CD-ROM, Modem)
- Externalize eqipment.

Going even futher : Desperation level : 2. I don't care about performance anymore.

- Other power consumption reducing measures : Clock Down CPU, System. (Dependent on PSU dynamics for effect). Lowering the Vcore voltage of the CPU,  FSB speed and clcock multiplier will reduce the power consuption of the system. Find a balance between stability, performance and noise level. NOTE ! The effect of this is negible if a software cooler is installed, but will set a limit for the max. system power-consumption.

- Alter HDD mode of operation from ATA to a slower IDE drive mode. Less seek noise.
- Changes in file system. ( Type and partitioning ).

Going over the edge : Desperation level : 3. I don't care if my system blows up.

- Disable fans. This is a realistic option with a small risk-factor in a properly configured system.  In a time of consumerism, this is maybe a sad but definitely cost effective remedy on many levels.  If this is the approach you wan't to take then check out this [ link ].

Philosophy (Essence) :

Prevention :

- Reduced noise level due to reduced power-consumption, which means less heat generation, which means lower cooling requirement, which means lower-fan speeds, which means less noise.
- Reduction of mechanical rensonance and vibration.

Redemption :

- Reduced noise level due to absorbtion and dempening of noise generated.

Dynamic Operation :

Reduced spiritual strain due to lower stress levels on idle system operation. Very important. The reason that the system is idle is most likely because the operator is in a meditative state, and more sensitive to distractions. Besides this a dynamic noise is prefrable to a static, as there is more "life" in it.

Other considerations :

- What kind of software do you run ? Heavy applications may be replaced by lighter ones. In essens this means going back in version numbers. Early succesfull releases are more efficient, than the over "improved" later versions. ex. internet explorer v4 vs later versions. winamp 1.9 vs later editions. Realplayer G2 vs V7 and V8. It's like a disease man ... starts out as a small utillity and takes over you whole computer, which becomes to slow ... which means that you will have to buy a more powerfull one ... consuming more power ... generating more heat ... more noise ... enabling the programmers to write even more power-full or power-consuming (pick one) applications ... slowing your once fast system down ... forcing you to upgrade to another new computer after installing their upgraded software. And so it goes on ... it's called progress ... to anywhere but here ... not necessarily forward.
Ummm ... guess I got carried away here. Possibly due to the strains caused by a recent install of microsoft media-player v7.0. A flying flashing circus with everything and anything, except fully functional CD track skip controlls. Sometimes I wonder if they do it on purpose.
A note on the CPUIdle(v5.06) shareware-utillity in this context. The small LED-like gauge meter in the system tray was usefull for detecting powerhungry and light applications.

Observations :

oo - Metal chassis and or components combined with mechanical motion is a poor combination. From what has been discovered sofare, theres materials transforms mechanical vibrations into high-frequency ringing noises. This may be one of the reasons why the carpet-damping method had such a good effect on the chassis,  reducing resonance. In addition to metal surfaces have a poor noise absorbing effect, working more as a noise mirror. reflecting allready existing accoustic noise comming from such sources as fan, drives, capacitors & coils.

oo - A firm support under the CPU area of the MB is important. Cooling fans may generate vibrations. etc. Alternatively some shock absorbing material if there is lots of vibrations.

oo - The "colour" of the noise is more significant than a "mathematical"   measurement of magnitude. This may make the difference between noise and sound. In general bassy sounds are preferable to treble-ish sounds. The difference is that of the soothing "noise" from the fireplace or the "sound" of traffic.

oo- dB Level Measurments. The numbers that a meter gives are deceptive, and does not give a limited amount of information about the accoustic environment. What is measured (presumably I'm not shureyet) is the average  energy level in a frequency range over time. I'm under the impression that sounds that feels low, still measure quite high on the meter. And that sounds that feels loud, measures low. [ Find some more info about this some time.] Anyway, noise levels under 28 dB are very good, and reductions below this level are not noticed so well as increases above. F.ex. A dicussion about 38 or 40 dB makes little difference. (I'm onto something here, but I don't know what ...).

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