Play-doh/BB composite - awesome sound dampening!

IsaacKuo · Post by **IsaacKuo** » Mon Apr 04, 2005 7:18 pm

I've been experimenting with sound dampening material suitable for my 2.5" notebook drive enclosure. I'm happy to report that a composite of play-doh and steel BB's works extremely well at absorbing sound and vibration.

I should note that I do NOT have a quiet 2.5" notebook drive. Both of my old notebook drives are loud--a lot louder than my quieter 3.5" drives. As such, it's pretty easy for me to just "earball" whether a sound dampening material is doing much good. However, there's a good chance that what's best for these loud 2.5" drives is NOT what's best for a quieter 2.5" drive.

My findings:

1. An enclosure is absolutely essential. Enclosing the drive fully by a metal box or a plastic box or even just a cardboard box is key to containing drive noise. Without it, even the best sound dampening materials I tried had a limited effect.

2. The $2 Walmart pharmacy hot-cold packs were not very good. They tended to transmit sound and vibrations to the enclosure. I'd say that suspending the drive in air was more effective than wrapping it in hot-cold packs.

3. Sandwich bags of steel BBs were effective at cutting down vibrations but only somewhat effective at cutting down noise.

4. Sandwich bags of Play-doh were more effective than steel BBs at absorbing noise, and a lot less heavy also.

5. Sandwich bags of steel BBs mixed in with Play-doh were more effective at cutting down vibrations and absorbing noise than either of the above alone or layered with each other.

I think that the composite structure was more effective because the BBs added mass and inertia while the Play-doh absorbed energy. Well, I'm less concerned with the theory than the practical effect--my loud 2.5" drive is quieter than ever before, and in a relatively compact enclosure (far smaller than the Maxtor box I had been using).

I still haven't gotten the thing down to the dimensions of a 3.5" hard drive, but I think I'm on the right track. My current enclosure is 3"x3.5"x5.5". With all of the steel BBs in it, it's heavier than a brick!

Here's are instructions for making these sound absorbers without making too much mess:

1. Put a blob of play-doh in a sandwich bag.

2. Poor BB's into the bag.

3. Zip up the bag with some air in it--enough to be able to manipulate the contents easily.

4. Through the bag, mash BBs into the play-doh and fold the play-doh to mix it around.

5. After the composite is mixed well, press the bag of stuff into the (empty) enclosure to form fit the block. Open up the bag slightly to squeeze the air out.

You want to make two of these blocks, to sandwich the drive between. The play-doh/BB composite is squishy enough to form fit around the drive with gentle pressing.

slipknottin · Post by **slipknottin** » Mon Apr 04, 2005 7:40 pm

What sort of temps are you getting with these enclosures? I must say, the idea is quite brilliant. Dont think I would have ever thought of play-doh.

IsaacKuo · Post by **IsaacKuo** » Mon Apr 04, 2005 9:21 pm

Temperatures? No idea. But when I remove a notebook drive from an enclosure after working for some time it's quite warm to the touch.

The main reason I'm doing this with my loud notebook drives instead of my quieter 3.5" drives is that I don't think a 3.5" drive could handle the thermal abuse nearly so well. I've had enough 3.5" drives die from overheating to not even THINK about doing this to a 3.5" drive.

Spod · Post by **Spod** » Mon Apr 04, 2005 10:22 pm

It might be worth re-sealing the bags after you've squeezed the air out, or the play-doh might dry out, losing its softness & dampening properties.
Perhaps you already did that, but I thought I'd mention it, since you hadn't.

TailsNZ · Post by **TailsNZ** » Tue Apr 05, 2005 3:14 am

That's a really original idea yeah, cool

Do you have a digital camera though, for some photos?

I'm curious if it heats up a lot in there too yeah.

IsaacKuo · Post by **IsaacKuo** » Tue Apr 05, 2005 5:43 am

Thanks for the praise, but I was actually inspired by a recent posting about using skulpting clay to enclose a drive. Doing a search on this forum's archives, it seems quite a few people have tried using modeling clay or playdough.

I only added the idea of mixing the relatively lightweight modeling clay with a much heavier matrix of BBs.

I don't know what will happen when the clay dries out. It will take a while, because it's within plastic sandwich bags and also within the box enclosure. The heat from the drive might have an effect, though.

I'm not too terribly concerned with the stuff drying out because it's trivial to replace (just take out the old bags and replace with new bags). Also, I suspect that most of the sound/vibration absorption is from the "foamlike" structure of the BB/clay mix, and that it would still work even if the clay were relatively stiff and/or crumbly. It's like a foam with bubbles of steel in it instead of air.

I have a camera; I'll make pictures tonight...

Tibors · Post by **Tibors** » Tue Apr 05, 2005 7:33 am

Maybe it is because I don't live in North America, but what are you talking about

I gather from the above that Play-doh is probably a brand of synthetic childrens "clay". But what are steel BB's?

IsaacKuo · Post by **IsaacKuo** » Tue Apr 05, 2005 7:55 am

Yes, Play-doh is children's modeling clay.

BB is a standard diameter of shotgun projectiles, which became popular in the 20th century as a projectile for cheap toy airguns. (A shotgun shoots a bunch of them at a time, a "BB gun" shoots just one.) Because of their popularity in toy airguns, they're available here in bulk, really cheap.

afrost · Post by **afrost** » Wed Apr 06, 2005 9:34 am

you could also try lead shot, lead shot is often used by audiophiles to fill their speaker stands for added mass.....usually a lead shot and sand mixture.

IdontexistM8 · Post by **IdontexistM8** » Thu Apr 07, 2005 12:01 pm

afrost wrote:you could also try lead shot, lead shot is often used by audiophiles to fill their speaker stands for added mass.....usually a lead shot and sand mixture.

Very effective it is too!..just don't try and lift anything afterwards

Marcus · Post by **Marcus** » Thu Apr 07, 2005 12:53 pm

I definitely agree with Spod, I'm pretty sure Play-doh is water-based. Once it dries out, there goes your dampening.

Post by **NeilBlanchard** » Fri Apr 08, 2005 2:24 am

Hello:

Maybe plumber's putty, instead of PlayDoh? It too, dries out eventually, but it would be longer lasting, I think; especially inside a sealed plastic bag.

IsaacKuo · Post by **IsaacKuo** » Fri Apr 08, 2005 5:42 am

To me, the question of whether sound dampening performance is significantly reduced by drying out is entirely theoretical right now. For all any of us know, sound dampening could remain the same or it might even improve as the modeling clay dries out.

I haven't had a chance to do much development on this project in the last couple days--the neighbors have been running some sort of god-awful pump on their pool for the last couple days. When it finally stops, I want to compare a clay-heavy mix vs a BB-heavy mix. Also, my current enclosure is being used in a less than ideal way--the <3" width gives so little room to the sides of the drive that I don't think I'm getting a perfect seal on all sides. Turning the enclosure on its side and using some cable-gami should improve things a bit.

Straker · Post by **Straker** » Sun Apr 10, 2005 1:42 am

could just add extra water to the playdoh before initially mixing, or use like $40 of silly putty instead.

if one were to do this on a reasonably large scale (ie more than one drive), it'd be pretty easy to just make your own, or use something like a huge blob of silicone caulking... lots of options for enclosing 2.5" drives.

palled · Post by **palled** » Sun Apr 10, 2005 5:12 am

Nice to see more play-doh experiments around!

Here's a link to my own play-doh silencer I made some months ago:

http://forums.silentpcreview.com/viewto ... 791#171791

Play-doh/BB composite - awesome sound dampening!

Play-doh/BB composite - awesome sound dampening!

Plumber's putty?