Page 1 of 2

As of right now, what is the best sound [dampening] product?

Posted: Wed Jul 30, 2008 11:21 am
by zhangmaster12
Just like the title says, whats the best sound dampaning product as of right now. Preferably purchaseable off of mcmaster.

Posted: Wed Jul 30, 2008 6:05 pm
by thunderpeteii
i dont know... i wish to know to though

acoustipack ultimate D: i dont known ;( help~

Posted: Thu Jul 31, 2008 6:05 am
by CyberDog
you cannot answer that if you dont know what you are trying to damp.

Posted: Thu Jul 31, 2008 6:58 am
by jhhoffma
Best overall dampening for panels? Best value? Best for HDD enclosures?

For cheap panel dampening, I use self-adhesive vinyl floor tiles (heaviest you can get) from the local home improvement store. You can also you the Acoustipack (and pay a bundle) or the Dynamat-style dampening materials.

It's all dependent on what you want to do an how much you want to spend.

Posted: Thu Jul 31, 2008 10:09 am
by Luminair
this is simplified possibly to the point of being inaccurate, but:

sorbothane for vibration isolation and probably vibration dampening

vinyl for vibration dampening via mass-loading and sound wave reflection

dense open cell foam for sound wave absorption

Posted: Thu Jul 31, 2008 2:17 pm
by JoeWPgh
Let me follow this up as I understand it:
There are 3 separate things often referred to as 'dampening'

There is the actual dampening of the case panels to deaden their vibrations. You do this if your case panels are audibly vibrating.

There is mass loading to increase the amount of mass the sound energy must penetrate. You do this to try and keep noise inside the box.

There is diffusion to break up the moving air of a sound wave. You do this to soften how sound waves hit the case panels.

For dampening, I like butyl. You need not cover every inch of a case panel to deaden it - just a few strips here and there - much like a drummer might use a strip of tape or 2 to control the vibration of his drum head. Of course if you cover the entire case panel with it, you've also mass loaded the panel, so you're 2 for 2.

For mass loading, self stick vinyl floor tiles are effective and cheap. I don't think they are quite the equal of butyl for dampening, but they take you a good way down that path as well.

For diffusion, I agree again. Open celled foam is the easiest solution. I usually save the 'egg-crate' bumpy stuff that some computer parts ship with for just such use.

Of course, you could gild the lily and apply all 3, and only add 15 lbs or so to your box :)

By far the easiest thing to do is to start with quiet components. This will usually negate the need for most case dampening.
Luminair wrote:this is simplified possibly to the point of being inaccurate, but:

sorbothane for vibration isolation and probably vibration dampening

vinyl for vibration dampening via mass-loading and sound wave reflection

dense open cell foam for sound wave absorption

Posted: Thu Jul 31, 2008 3:51 pm
by thunderpeteii
okay i have

a P180
800 RPM Slipstreams
a xigamatek s1283 with a slipstream.
An accelero 8800 GT With A slipstream.
I have an Athlon X2 6400+ (which is quite hot).
I have a Kama Bay in the front.
The top is blocked off.

The vibrations are nil... Because I have A 640gb caviar blue in quiet drive on foam.

However I just wish to dampen the whoosh sound of the air without increasing temps.The nforce 490 gets quite hot as Well as The CPU. I have the slipstreams running at 700 RPM

I do not really want to increase temps. Or lower fan speed. So I was wondering if the acoustipack would be just a little boost. To lower the whoosh sound.

And if I get acoustipack if I upgrade in the future with a cooler processor and motherboard etc. I can still use the case with acoustipack or whatever damping. But at the moment shelling out 300 dollarsish for a cooler processor and mobo combo, is much worse than shelling out 50 dollars for acoustipack ultimate. And having a quieter case for the future as well.

Basically I was wondering if acoustipack was the best way. Or where you can get comparable egg crate foam (if that's what Softens the whoosh sound). Or if it would do basically nothing at all. And i should just leave it as is.

Sorry for the lack of grammar etc... I'm just not particularly good at writing cohesively on boards for some reason.

thanks

Posted: Thu Jul 31, 2008 4:32 pm
by hukares
You need a deadening product to control vibrations/low freq. noise.
You need an absorption material for the higher pitched sounds.
For a deadening product, I recommend butyl rubber. That's what the better audio dampening products are like you'll see in the car audio store. It sound like you won't see much benefit from this. To absorb higher pitched noise, I use neoprene foam. You can also buy this from car audio stores, but only the better ones - not Best Buy. I use both products in both my computer and my pickup truck. Works great.

Posted: Fri Aug 01, 2008 5:21 am
by Hypernova
From what I have read so far what cases like P18X's need are really just the foams to absorb and down tone the sound. The panels themselves are thick enough not to vibrate. The best specialised foam (thin, dense, but still foam) for cases would then be Acustipacks. Akasa's from what I read so far appears to be nothing but snake oil, Mike has stated that they are too thin to do anything and many posters have also reported that they didn't help when used.

Posted: Fri Aug 01, 2008 7:30 am
by jhhoffma
Hypernova wrote:From what I have read so far what cases like P18X's need are really just the foams to absorb and down tone the sound. The panels themselves are thick enough not to vibrate. The best specialised foam (thin, dense, but still foam) for cases would then be Acustipacks. Akasa's from what I read so far appears to be nothing but snake oil, Mike has stated that they are too thin to do anything and many posters have also reported that they didn't help when used.
You are correct about the cases. You can go to a local store and pickup some upholstery foam cheaply and put that on the inside of your PC temporarily and see if you notice a difference, before you plunk down a sizable chunk of change on some Acoustipack or the like.

It won't be a miracle worker, but you should notice some difference.

Posted: Fri Aug 01, 2008 7:57 am
by psyopper
My wife recently went to Wal Mart and picked up a box of 12 "Magic Kitchen Erasers" - essentially generic Mr. Clean Kitchen Erasers which are actually Melamine foam. I think she paid about 8-10 USD for the box. Each pad is roughly 3"x5" and 1" thick. Laid out this will give you a 12" x 15" panel of 1" foam.

It's hard to find Melamine this cheaply elsewhere and I have seen reference that it is one of the best closed-cell foam sound insulators for high frequency noise out there.

Posted: Fri Aug 01, 2008 6:44 pm
by jhhoffma
psyopper wrote:My wife recently went to Wal Mart and picked up a box of 12 "Magic Kitchen Erasers" - essentially generic Mr. Clean Kitchen Erasers which are actually Melamine foam. I think she paid about 8-10 USD for the box. Each pad is roughly 3"x5" and 1" thick. Laid out this will give you a 12" x 15" panel of 1" foam.

It's hard to find Melamine this cheaply elsewhere and I have seen reference that it is one of the best closed-cell foam sound insulators for high frequency noise out there.
Yeah, but those things are usually full of baking soda, I don't know if I'd want them in my case sucking all the moisture out of the air. They'd start to smell eventually.

Posted: Sat Aug 02, 2008 3:29 am
by jessekopelman
JoeWPgh wrote:Let me follow this up as I understand it:
There are 3 separate things often referred to as 'dampening'

There is the actual dampening of the case panels to deaden their vibrations. You do this if your case panels are audibly vibrating.

There is mass loading to increase the amount of mass the sound energy must penetrate. You do this to try and keep noise inside the box.
I don't think this is correct. What you are calling dampening is the same thing as mass loading and vice versa. Simply increasing mass does not somehow make it harder for sound to penetrate. You add mass to reduce vibrations. Vibrations are one source of sound. Stopping sound from penetrating is pretty damn hard to achieve, as we are talking about wavelengths in meter range -- you basically need a thickness of material that is a significant fraction of the wavelength. Thickness is the key, more so than material. Getting in really close to the source (eg hard drive boxes) seems to do the trick in with fairly thin material, but I'm not sure of the physics behind it. I'm guessing something along the lines of preventing a wavefront from forming at the audible frequencies (where the wavelengths are relatively large).

Posted: Sat Aug 02, 2008 11:35 am
by jhhoffma
jessekopelman wrote:I don't think this is correct. What you are calling dampening is the same thing as mass loading and vice versa. Simply increasing mass does not somehow make it harder for sound to penetrate. You add mass to reduce vibrations.
That is correct (mostly). Mass does play a roll, though. Think about this--if you have a single frequency you are trying to attenuate by matching the distance of the wavelength, which would be more effective: a sheet of paper or a film of lead of equivalent thickness? Density matters, but you're correct in saying that in most cases of PC proportions, mass-loading has the most effect on resonance and sympathetic vibrations.

Foam is effective for reducing reflections of high-frequency (short wavelength) sounds/vibrations.

Posted: Sun Aug 03, 2008 2:23 am
by jessekopelman
jhhoffma wrote: That is correct (mostly). Mass does play a roll, though. Think about this--if you have a single frequency you are trying to attenuate by matching the distance of the wavelength, which would be more effective: a sheet of paper or a film of lead of equivalent thickness?
Sure I agree. But again we are really talking about a mass loading effect -- it takes far more energy to get that sheet of lead to vibrate. Dampening = Mass Loading, for all intents and purposes. Anyway, even using a 1" of lead, I bet it will do very little against sound waves that have a 1m wavelength. Speed of sound is ~ 340 m/s. A 7200 RPM drive rotates at 120 Hz -- wavelength of ~ 2.8m! You're just not going to stop that with any kind of materials applied to the case. What people need to understand is that "dampening" materials are primarily good for one thing and that is stopping any additive noise from case panels vibrating. It will not help with sounds propagating through the air inside the case. However, if you apply enough to prevent any air entering/escaping from the front and sides you will get will get the acoustically beneficial effect of being rid of any airflow noises in those directions (but your airflow design better be able to tolerate it!). I think what a lot of people are misunderstanding about PC noise is that in addition to primary noise generators like fans and HDD, which are very hard to do anything about, there are additive noise factors like panel vibration and airflow ingress/egress. It is these additive noises that case treatments deal with. That is all well and good, but in the end you will still be left with the your HDD's internally generated noise which is likely to be audible. I haven't tried one of these drive silencing boxes yet myself, but many claim they work. I would hope people asking about "dampening", and there seems to be someone new each week, puts getting one of these boxes higher on their list than buying a bunch of foam and butyl tape.

Posted: Sun Aug 03, 2008 2:35 am
by jessekopelman
jhhoffma wrote:Foam is effective for reducing reflections of high-frequency (short wavelength) sounds/vibrations.
Agreed, but I wonder if these really exist much inside the PC. Squealing caps and fan motor noises, I guess. Fans are spinning in the 10s of Hz. HDD are spinning in the 100s of Hz. These are low frequency noises. I'm sure there are higher frequency resonances generated, but they must be by nature much lower energy. I claim if foam is doing something for people it is most likely sealing areas of airflow ingress/egress, not blocking noise generated within the case. I have self-installed foam over butyl in my NSK3300 case, so my opinion comes from empirical study and theory.

Posted: Sun Aug 03, 2008 7:30 pm
by jhhoffma
jessekopelman wrote:Agreed, but I wonder if these really exist much inside the PC. Squealing caps and fan motor noises, I guess.
Exactly, we can't get rid of the low frequency cycling noises however, drive whine and fan motor noises are much higher frequency and can be reduced slightly. No miracles here, though.

I will say that I use headliner foam over S/A floor tiles inside my SLK3000B, and the foam does reduce the harshness of the noise inside the case that is left when just using floor tiles.

Posted: Sun Aug 03, 2008 9:10 pm
by JoeWPgh
Floor tiles are very reflective, acoustically. There's really no difference between them and the bare metal of the case panel. Open cell foam diffuses the direction of the air movement before it slaps the case panel. Setting aside the wavelengths, lower frequencies move more air than higher frequencies at the same relative volume. This is why foam is considered effective for higher frequencies. There's only so much it can do, and you'd never fit enough foam in the case to have an appreciable effect on the moved air of lower frequencies.
jhhoffma wrote:
jessekopelman wrote:Agreed, but I wonder if these really exist much inside the PC. Squealing caps and fan motor noises, I guess.
Exactly, we can't get rid of the low frequency cycling noises however, drive whine and fan motor noises are much higher frequency and can be reduced slightly. No miracles here, though.

I will say that I use headliner foam over S/A floor tiles inside my SLK3000B, and the foam does reduce the harshness of the noise inside the case that is left when just using floor tiles.

Posted: Mon Aug 04, 2008 1:50 pm
by jessekopelman
JoeWPgh wrote:Floor tiles are very reflective, acoustically. There's really no difference between them and the bare metal of the case panel. Open cell foam diffuses the direction of the air movement before it slaps the case panel. Setting aside the wavelengths, lower frequencies move more air than higher frequencies at the same relative volume. This is why foam is considered effective for higher frequencies. There's only so much it can do, and you'd never fit enough foam in the case to have an appreciable effect on the moved air of lower frequencies.
Floor tiles are considered an option to butyl tape for mass loading. The idea is to reduce secondary noises created by panel vibrations, not somehow block airborne noise originating inside the case (which we all agree is not possible except for high frequency noises which are rarely a big issue). Some cases as prone to vibrating panels and mass loading is the cure.

Posted: Wed Aug 06, 2008 7:54 am
by fnwtmp

Posted: Wed Aug 06, 2008 11:51 am
by jessekopelman
fnwtmp wrote:Has anyone tried these?

http://www.dealextreme.com/details.dx/sku.12999
Looks similar to the self-adhesive butyl products sold by Elemental Designs - eDead V1SE2 ($1.60/sqft). Good for mass loading . . .

Posted: Thu Aug 07, 2008 8:27 am
by Nighthog
Have any of you tried "be quiet! PC NOISE ABSORBER KIT"?

I bought a Universal big tower kit for my computer consisting off a Lian-Li PC-A01B case. And it effectively by my hearing reduced noise by half in general and in all removed the vibrations off the case all over to zero in that you could hear them. The case does still vibrate if you feel it but it doesn't generate sound. (badly designed hdd cage that moves vibration from hhd's to the entire case directly)

I used about 90% of the whole package into my case and it really did reduce the noise off it all.

The package consists off 5x 400mmx220mm pieces off 2.2mm betyl I think and 8mm fine/dense foam and 1 piece off 20x400x220mm fine/dense foam. It cost me about 300kr (swedish currency. 1 dollar about = 6kr, so 300/6= 50$)

I'm really happy whit it.

Posted: Thu Aug 07, 2008 6:17 pm
by amps
After doing a lot of research into noise reduction materials I decided that the only way for me to reduce the noise in my already quiet P180 was to use noise absorption material.

I did a lot of research on materials to use and the science behind it. Like lots....every night for a week from 10PM-5AM. I spent a lot of time on sound engineering sites and Home Theater forums. I finally settled on either a rigid-fiberglass or mineral wool product. I decided to go with mineral wool since the idea of fiberglass particles getting blown around by my case fans and into the air seemed...I don't know, bad. I found a great product made by Roxul called Roxul AFB. It has a reduction co-effecient of 0.94 at 500hz at a thickness of 1.5". AFB is used specifically as a sound reduction product in construction.

I called around to all the local distributers and found a supplier that had one bundle of the AFB in 1.5" and picked it up for a cool $32. The bundle when wrapped and compressed is 3x2x2 feet, thats a LOT of material for a lot of cases :) I cut out pieces of the insulation in layers and then wrapped it using a light meshy Nylon material with thin cardboard on the back for support. I made bundles to cover above/below the lower hard drive caddy with the drive suspended inbetween. I made a thick bundle that fit perfectly in the 5.25" bays with enough room for my Bluray drive. The rest of the bundles were made to fit around cables, above the PSU and in every crack I could find.

For results, my case is dead silent. It was quiet before but could easily be heard from 3-5ft away. For reference, my rig consists of:

Antec P180 with 2 Yate Loon 1200rpm fans (volted to 1000rpms using Fanmates),
Fanless Scythe Ninja on the Core2 6300 CPU
Aerocool Accelero S1 on the ATI 3850
Seasonic S12-II 420
Suspended WD 250GB hard drive

I can no longer here my PC unless I put my ear right next to the case or the odd time when I leave the front door open and the hard drive seek noise goes through the front grill. Overall, I am pretty darn pleased with my little DIY project. At less then half of the price a dampening kit (Accoustipack) I have enough noise absorbing material to outfit 100 cases and I feel the effect is much better then any dampening products on the market. You need to make sure that you've done your best to quiet all the other components before undertaking something like this though, there just isn't enough room in a case to cram the absorption material in to suck up all the noise. Also, at the lower frequencies (sub 200hz) you can only hope to reduce the noise by less then 20%.

Posted: Thu Aug 07, 2008 11:12 pm
by Happy Hopping
I have a few questions as to what to do w/ my case. My computer is:

-) hp xw9300 workstation

-) 4 x hard drives at the bottom bays just above the front cooling fan

-) 1 x Cooljpg 12 cm front fan (just about to buy, upgrade from my nexus)

-) system c/w a rear HP OEM fan, which is a NMB-MAT 50 dB (at max speed), 129.957 CFM, 3600 rpm fan, the fan is variable speed controlled by Motherboard

-) 1 x DVD-ROM drive, 1 x DVD+RW drive

-) Video card is heat sink only

Here's the problems:

1) it's not noisy but audible during daily use, and I use this machine easily 12 hr. / day

2) On occasion, when I do play PC game, the fan really shot up to the max., and even w/ the loud speaker sound, I can easily hear the fan noise

I would be happy if I can reduce some degree of PC noise cause by the rear fan, power supply fan, and vibration noise of those 4 hard drives

However, I wouldn't allow these noise dampening material to downsize the noise but increase the temperature of the PC case. If so, I would rather put up w/ the noise

Now from bit-tech.net review, they said that "Be Quiet! PC Noise Absorber Kit" could be heating up my case. So I'll pass on that one.

The only things I can think of is:

1) AcoustiPack, would it absorb some noise from the front and rear sys. fan, power supply fan? Or is the noise generated by what's coming out of the case, in which there is nothing I can do?

2) anti-vibration screw for my hard drives

Having said the above, is there anything further I can do?

Posted: Fri Aug 08, 2008 2:56 am
by Aard
Reading through this thread, I remembered that some cars use composite materials (foam and vinyl layers) in engine bays to deaden the noise of the engine. These materials have to damp a lot of reasonably low frequency noise but also some high frequency noise as well, a situation somewhat similar to what you might find in a reasonably noisy computer (although somewhat louder I hope :lol:).

Following this train of thought I searched for what was on offer to DIYers and stumbled across a man after our own hearts, he coated his Mazda 3 in around 30-40 kg of dampening material. You can see a thread about it here.

In the afore mentioned thread there is a link to this site, which compares automotive based dampening materials. To cut to the chase, the best material is supplied by http://www.secondskinaudio.com/ while the best value material is available at http://www.raamaudio.com/.

These products while typically sold in car sized quantities (funny that!) can also be available at relative reasonable prices, provided you choose the right product. Second Skin sell 'Luxury Liner' at $40 US for 9 sq ft (approx 0.83 m^2), this is roughly enough to do 4 ATX side panels. Compare this with AcoustiPack and its a relative steal (although I don't know the performance difference).

Perhaps one of us is brave enough to take a gamble on such products? I would do it myself but I have not the equipment nor the need. Maybe time for another dampening review?

Posted: Fri Aug 08, 2008 8:29 am
by jessekopelman
Aard wrote:Reading through this thread, I remembered that some cars use composite materials (foam and vinyl layers) in engine bays to deaden the noise of the engine. These materials have to damp a lot of reasonably low frequency noise but also some high frequency noise as well, a situation somewhat similar to what you might find in a reasonably noisy computer (although somewhat louder I hope :lol:).

Following this train of thought I searched for what was on offer to DIYers and stumbled across a man after our own hearts, he coated his Mazda 3 in around 30-40 kg of dampening material. You can see a thread about it here.

In the afore mentioned thread there is a link to this site, which compares automotive based dampening materials. To cut to the chase, the best material is supplied by http://www.secondskinaudio.com/ while the best value material is available at http://www.raamaudio.com/.

These products while typically sold in car sized quantities (funny that!) can also be available at relative reasonable prices, provided you choose the right product. Second Skin sell 'Luxury Liner' at $40 US for 9 sq ft (approx 0.83 m^2), this is roughly enough to do 4 ATX side panels. Compare this with AcoustiPack and its a relative steal (although I don't know the performance difference).

Perhaps one of us is brave enough to take a gamble on such products? I would do it myself but I have not the equipment nor the need. Maybe time for another dampening review?
Elemental Designs sells pretty much the same stuff and they do it by the square foot. In the thicknesses you will actually be able to apply in your case it doesn't do anything significant for low frequency (eg HDD) noises. A non-luxury car has major vibration issues, so mass loading is going to make a huge difference -- not so much for a PC. There is no magic stuff out there people! It is all basically butyl for mass loading and a layer of foam to get rid of high frequency noises.

Posted: Sun Aug 10, 2008 9:42 pm
by yukon
Mass loading is relatively easy. Glue heavy stuff to the box. Floor tiles work great.

Absorption is difficult. Mineral wool tended to come apart, and ISTR it changed colour here after some time, and smelled bad (probably just the sample). I've seen a number of foam types degrade over time. On many of the car products, I see a very thin layer of foam; to be honest, fabric is probably better. It can be be thicker, washable, and there's a lot of variety. It'll last, and it's inexpensive. It's light enough that one can use velcro instead of gluing foam to the case.

Posted: Sun Aug 10, 2008 11:52 pm
by Aard
jessekopelman wrote: Elemental Designs sells pretty much the same stuff and they do it by the square foot. In the thicknesses you will actually be able to apply in your case it doesn't do anything significant for low frequency (eg HDD) noises. A non-luxury car has major vibration issues, so mass loading is going to make a huge difference -- not so much for a PC. There is no magic stuff out there people! It is all basically butyl for mass loading and a layer of foam to get rid of high frequency noises.
Oh, I didn't say it would do magic. I just thought it might be an avenue that people haven't looked at, which could be cheaper than the "specialised" computer foam.

Posted: Thu Aug 14, 2008 5:28 pm
by seasponge
amps wrote:After doing a lot of research into noise reduction materials I decided that the only way for me to reduce the noise in my already quiet P180 was to use noise absorption material.

I did a lot of research on materials to use and the science behind it. Like lots....
it looks like you found a good solution for yourself, could you by any chance post some pictures of this stuff in use or in its bulk state? does it smell? thanks for the intriguing post.

Posted: Thu Aug 14, 2008 6:19 pm
by yukon
Oh, you can get it in Home Depot type stores in building materials. It's a replacement for fiberglass. Rock wool, a type of mineral wool like fiberglass, is more expensive, but more fireresistant, so they're using it as premium insulation now. Roxul's promotional materials a few years ago said it had far better soundproofing ability, but I've been told fiberglass is excellent. They put oil or starch in the rock wool, and I'm not sure if that's an issue for PCs, but it's to help keep the smallest particles on the batting. I know the material as a hydroponic growing medium mostly, and the smell probably came from anything growing in it (maybe my sample got wet, or something organic spilt on it).

I have some bad news though. Fiberglass and Rock/Stone wool are both mineral wools, and both have inherent health dangers as irritants and carcinogens. Here's an MSDS-
http://www.ilo.org/public/english/prote ... sc0194.htm

My solution was to completely enclose it in polyester fluff and then cover that with fabric with a carpet underlay backing, but it was just nasty material to work with and have around daily. I don't use it anymore, but better construction of panels could reduce exposure. I threw my homemade panels away within a year. I can get a how-to page on panel construction if anyone still wants to work with it.