[Zwilnik]

Ever since the convection cooled iMac came out I've been jealous (well, until I got my iBook), my G3 B/W sounds like a Jumbo Jet warming up thanks to all the fans in it.
Now I don't want to remove any fans (not with 3 HD's in it), but I was wondering if anyone has any good ideas about reducing fan noise (and possibly case noise) on a desktop.
I was even considering feeding back a phase reversed sound to it (sound from the noisy thing, reverse phase it, play it back from a speaker at exactly the same level, cancels out 99% of the noise), but this is tricky and expensive.

[exa]

You could replace the fans themselves with quieter fans... I've seen comp fans that make no noise, kinda freaky, but true, look into those...

[sine -''-..-]

There are definately some Very quite fans out there... Iv seen some in AST(ungh...) low cost office computers...
the harddrives are also in sound dampening cases so the thing makes VERY little noise... cant tell its on!

But of course, the quiet fans may not move as much air.

[Feathers]

I think most fans start off pretty quiet but wear noisy very quick. I got an external USB-IDE casing from www.blol.com/ - Lovely case the the fan is now the most annoying sound on my desktop. I only turn the drive on when I absolutely want/need to use it!

I think quality ball or roller bearings would probably double the price of the fan anyway.

[Cipher13]

You haven't heard noisy until you've heard my external HD - its like so old, it has those massive chunky SCSI ports that wont even work with newer SCSI cards, is about a foot wide, a foot long, and about 15 CM's high, and holds 40 megs!!!!!!!!!! MEGABYTES!!!!!!!! This thing sounds like a helicopter taking off!!
My yamaha 8424SX-VK isn't all that much quieter either...

[Zwilnik]

hmm, I'll have to look into the quieter fans options, however, the ones in my G3 are the 2 built into the power supply, which I'm otherwise quite happy with.
I'm going to look into ways of dampening the looser components in the case, to try and soundproof the box itself. A lot of the sound seems to be sympathetic vibration of the case door and other components.

[Feathers]

Hey man, get those sympathetic vibrations!

simple but somewhat effective:
1)get a scrap piece of low-nap carpet to put under tower or desktop base.
2)if possible put tower or desktop on floor
That will move the sound below level of your ears.

[Zwilnik]

Good idea. A kind of Mac drum riser

[Misha]

I replaced both the fans in my PowerCenter a while back with quiter ones. PowerComputing made some of the loudest machines out there... even with the quieter fans it makes a lot of noise, and the Baracudda drive in it doesn't help one bit.

You can replace the fans in the power supply without replacing the power supply itself, just open 'er up. It'll void the warranty, and you may fry yourself; just be careful.

[Zwilnik]

Is it an unwelding job on the power supply to open it up ? Or are they just screwed together nowadays ?
If it's just a case of unscrewing it, that's not too bad, although I don't have a high power soldering iron if the fans require desoldering from high voltage cables (by high voltage, I mean 12v, which usually has heavier solder).

[Misha]

It's just a few screws to get the power supply apart. No soldering was needed, either, at least not for me. I just had to splice the old fan, which had a regular power connector, with the old fan's mini power connector. No big deal, all you need are some wire cutters and some electrical tape.

Your results may vary.

I too have made a powercenter quieter. used custom cut cardboard. I fit it into my case and it absorbs some of the sound. You could probably take the idea and put some cardboard in your case but then you are definitely relying on convection cooling of fans and not any conduction/radiation through the case itself.

I've heard that running a fan at 5v instead of 12V can dramatically reduce the noise level. I haven't done any experiments but I think you can more the same amount of air for less noise by doing 2 fans at half the speed.

[Macnerd]

Originally posted by shopdowneast:
simple but somewhat effective:
1)get a scrap piece of low-nap carpet to put under tower or desktop base.
2)if possible put tower or desktop on floor
That will move the sound below level of your ears.

On the face of it #2 sounds sensible, but it can cause worse problems. Consider this. You have a carpet on the floor of the room your Mac is in. You put the Mac on the carpet. The carpet insulates the base of the Mac and reduces airflow around it (Yes - The rubber feet on the Mac are actually for something!). This in turn keeps the heat in. Not good. Also consider.....You put the Mac on the carpet. As you move around in the room you create dust, dust settles on the floor. The dust on the floor then gets dragged in (at floor level) by the fan which then accumulates masses of extra dust on it and the inside of the CPU, especially the processor' and it's heat sink. This again insulates the Mac and the fan in a roundabout way and you get a noiser, hotter Mac.

Sorry to drop this bummer..... I wish I too could find a good way apart from the Peltier Cooling method (VERY good but also VERY risky if not done right, and ugly too). My 9500 (fax server) runs almost 24/7 and my GF and I even look forward to Saturday evenings at 11pm when we turn it off so we can sleep for one night a week without that awful fan noise!!!!

There MUST be a better way! Ofd course the ultimate upgrade can be found at: www.macaquarium.com

;-)

Macnerd

[Zwilnik]

The airflow problem isn't much of a problem with my B/W G3, as it's stood on a slatted shelf, 3 inches above the floor. So If I put carpet or similar padding under the feet, or do a suspended riser, then the airflow would probably improve.
I'm looking at finding something to improve the join between the door and the rest of the case to reduce the possibility of vibration in the case.
The slower fan concept is a potentially cool idea too. A slower, but higher torque, fan with bigger blades that don't stall as they move through the air, would be a lot more efficient and quieter. Although I somehow doubt that any of the fan manuafacturers have aerodynamicists on the payroll

[robo from AI]

Fans come in two types - sleeve bushing axeled and ball bearing axeled. Ball bearing fans are quieter and last much longer, but cost more (not much more though... the most expensive fans don't cost more than $30).

I don't have a G3/G4, so i don't know what type of fan they use, but it's possible that they use the cheaper sleeve bushing type. One idea might be to remove the fan, and take it down to your local electronics store - they should have a bunch of fans and you can compare noise levels (take a 12 volt adapter, or a 9 volt battery, in case they don't have a power supply on hand).

As for rattling casings, a few well placed blobs of silicone caulking (the kind used in fish tanks and bath tubs) might do the job. It's clear, heat reisistant, and nice and squishy when it sets.


-robo

I have a B&W G3.

I disconnected the large PCI fan and stuck a toothpick in the power supply's internal fan to stop it.

The box is still noisy as ever.

It's because of the damn HDD. The fans are already relatively quiet.

re Noise proofing your Mac[sorry longish post]

In answer to post about putting a toothpick in the fan...you WERE just kidding right!!!. I have an 8500 w/G3 upgrade with two reasonably noisy 4 gig internal drives.I removed them from their sleds and isolated them from the structure with felt discs you can buy to stick on the bottom of furniture to prevent the scratching of floors.Make sure that the felt does not cover or inhibit airflow to any circuitry on the drives. The 8500 tower itself is acoustically isolated on the floor inside a mini-room of upholstered fiberglass [2" thick@3 lb/cubic ft density] which freely allows cool air to enter yet presents no direct sound path to my work position.This treatment has made the computer quiet enough to allow critical listening decisions to be made while performing sound recording and mastering in my studio.In some Macs where there is enough room, you can often achieve total structural isolation of drive generated noise by ripping apart bungee cords [they are composed of a number of smaller diameter bands] and suspending the drives in a rubber spiderweb of your choice! This will make a huge improvement in the low freqency rumble and sympathetic vibration department but will still not help much with that annoying airborn buzz etc from the drive's motor. For this you can attach a thin 1/2" thick layer of acoustic ceiling fibreglass to any other surfaces such as the inside cover that are free and clear of components. Use gloves to prevent glass slivers. Using a utility knife, try to achieve a mild pressure fit. Use double-sided tape or contact cement and mount this material finished or fabric side out to minimise any minor fiber shedding that might occur. Using duct tape at any joins will also help in this matter. Make sure the material is mounted securely. Don't skimp on adhesive. It would be counter-productive if a piece fell down onto your CPU raising the temperature to 10,000 Kelvin...sorta like a Pentium.These modest steps, in whole or in part, will provide a major decrease in noise and a lot less mental fatigue.

Good luck

Mako

[Ca$h68]

Hrm... whoever said that they need a fan with more torque at lower RPMs...uh... heh. No. That doesnt make sense. Increasing the torque on a tiny little fan would probably do almost NOTHING. They areny moving that much air anyway, so there isnt that much resistence to slow them down in the first place. Hope you were joking.

Oh yeah, and if the fan is moving half its original speed, its moving half the original air, and the chip will get hotter. Right?

Ca$h

I've got it! Mount an industrial size fan outside the building like an air conditioner condensor. Position the fan so it is blowing into a duct that leads into the mac. This could be very quiet. I'm going to start digging the duct trench this afternoon!

My Beige 266 is fairly quiet (although I'm getting a 500mhz g3 upgrade tommorow) I've heard that my case can get fairly hot and with an overclocked voodoo 3 inside it I am looking into fans and thermal gunk to cool off my cpu. Anyway, I have my g3 on top of a plastic milk case turned upside. The ones that milkmen used to carry milk bottles in. Works pretty slick and ventilation isn't a problem...might have a tough time finding one of these though, but if you got them around, use em!

[Zwilnik]

When I was talking about a lower RPM, but higher torque fan Ca$h, it would have wider chord, higher angle blades, able to push more air with the increased torque.
Being lower RPM, it would be quieter, it would just be converting the same amount of power differently.
cool different !

Does the fan noise have to do with the mechanical lubrication wearing evaporating off? Has anyone ever tried lubing their fans?
It seems like a plausible solution/explanation.

[Zwilnik]

When we used to have fan problems with older machines, lubricating them tended to have the opposite to the intended effect, dust got caught in the oil and clogged up the fans.

Originally posted by pdot:
Does the fan noise have to do with the mechanical lubrication wearing evaporating off? Has anyone ever tried lubing their fans?
It seems like a plausible solution/explanation.

Fan noise has alot more to do with aerodynamics than lubrication. The more fins a fan has, the louder it will be. The sharper the angle of attack on those fins, the louder it will be. The faster it spins... you get the picture. What you're hearing is the fins slapping the air as they spin more than the mechanical parts rotating, usually.

[Ca$h68]

Ah. Got ya Zwilink. Think the quality is more important than anything else.... better bearings = quiet.

Ca$h

[namannik]

Regarding putting a piece of carpet under the computer- I once did something similar to this with an old SCSI drive. It reduced air flow so much that it blew the fuse in the hard drive!

[Zwilnik]

Seems like fan noise is the main problem on my b/w. The case is vibrating sympathetically with the fans a little, so it's amplifying it, but it's mainly the psu fans. I'm going to try and (very carefully) clear them of dust today and see if that makes any difference (although the dust will be back within a week

[Misha]

Check to make sure that none of the cables inside the Mac are rubbing up against the fan, as that can produce a very annoying sound that can make the fans sound like they're much louder than they are.

[Zwilnik]

I did a general clean up inside my G3. No cables were rubbing, but as usual there was a lot of dust.
I cleaned out the dust from the fans, put some draft excluder around the inside where the door contacts the case and the noise was *slightly* reduced.
I think ultimately, replacing the fans and giving the case a full soundproofing treatment will be in order. That or implementing my theoretical particle accelerator cooling system.

[Zwilnik]

Hmm, what about removing the power supply and mounting it in an external box (with its own soundproofing). I could then put a single, quiet fan in the G3 case.