isolation products

Oli · Post by **Oli** » Mon Apr 21, 2003 12:38 am

[deleted]

powergyoza · Post by **powergyoza** » Mon Apr 21, 2003 12:52 am

digitalix, you stole the answer right outta my mouth!!!

Post by **MikeC** » Mon Apr 21, 2003 2:24 am

so there's not much vibration to dampen

I beg to differ on this. You are right if you are saying the grommets don't do as much as suspensions (homemade or novibe), which I agree totally with. But this statement I disagree with... Seagate's white paper on HDD noise is a must-read for hardcore silencers. It says:

"a drive that sounds quietest while suspended in an acoustic measuring chamber may actually sound louder when mounted in a system, while a drive that sounds quietest when in a system may not be the quietest when tested stand-alone. Several factors contribute to this disparity, including prominent tones, structure-borne acoustics, measuring techniques, objective measurement versus subjective hearing and so on. (emphasis mine)...

"Seagate has considered the total effect of drives on a PC system and can show that structure-borne noise is the dominating source of disc drive-induced PC acoustics. In fact, testing has shown that changes in stand-alone drive acoustics had little effect on the overall system acoustics when drives were hard mounted in the chassis...

"Seagate has made significant progress in the area of isolator design and development. Isolators are mounting mechanisms made of a softer material than metal; they are used to separate, or isolate, the drive from the chassis, minimizing the transmission of structure-borne vibration and noise."

pingu666 · Post by **pingu666** » Mon Apr 21, 2003 5:23 am

they will help, but by how much? thats the question

Mr_Smartepants · Post by **Mr_Smartepants** » Tue Apr 22, 2003 7:35 am

The grommets won't help (much) with the motor whine itself. What the grommets are good at is keeping the case from amplifying the motor whine or vibrational noise. That's why decoupling your hard drive has an apparent noise reduction. They remove the noise amplification inherent in all PC cases.
As an example, take a medium/high speed fan and plug it into a 12V source and hold it (carefully) in your hand. Yeah, you hear the whoosh of the air right? Now touch the fan casing to some bare metal of your case. Now you hear an additional buzzing right? That's the case amplification I'm talking about.
All components that vibrate will benefit from decoupling using grommets (where practical). How much so depends on the frequency harmonics of your particular case.

To remove the motor whine (or other noise that's perceived in free air), the only practical method is enclosing the offending device in a rubber case lined with both closed-cell and open-cell foam or other noise absorption/blocking material and adding sufficient cooling to compensate for the inevitable heat increase.

Tigr · Post by **Tigr** » Wed Apr 23, 2003 1:26 am

I had a very good experience with these "swing noise blockers". They are, basically, two steel plates joined by a piece of soft rubber. Installs easily and makes my WD much quieter.
http://www.colorcase.be/html/spading/np.php