On 2/25/2014 3:28 PM, Jerry Stuckle wrote: ... > Encasing the tower in a sound
"Damping" not "dampening". To dampen something is to add moisture to it. To damp an object is to lower its resonance frequency. One cannot add moisture to sound waves thus there is no such thing as "sound dampening". Please use the correct terminology. Saying "sound dampening" is like fingernails on a chalk board to audio engineers. > On 2/25/2014 4:16 PM, Stan Hoeppner wrote: >> Build a 3 sided box out of 3/4" MDF... > Just ensure there is enough ventilation (remember air > has to get in also, not just out) and that you can access the power > button, DVD, USB ports, etc. A 3 sided box is by definition open at the front, rear, and bottom, so front panel access is not an issue. > Making access holes for these without > compromising the sound dampening is probably the hardest part. Not at all. The goal here is not to make the workstation completely silent, but to decrease the SPL of the mid and high frequencies to little more than room background noise level at the ears when seated in the desk chair. An acoustically damped 3 sided box with small front/rear overhangs accomplishes this, in the two ways that matter: 1. The damping material, whether carpet or acoustical egg crate foam, absorbs most of the mid and high frequency sound energy generated by the fans. These sound waves normally radiate not only out the front/rear case vents, but also through the thin sheet steel and plastic panels which tend to resonate at or near these frequencies. In the stock configuration the fan noise radiates in all directions, but not uniformly. 2. Because the sound pressure level of mid/high frequencies drops at a much higher rate off axis from ear position, any sound energy at these frequencies not absorbed by the damping material propagates at floor level out the front and back only. By absorbing most, then directionally focusing the remaining mid/high frequency waves, which are now of greatly decreased amplitude due to the damping material in the overhangs, the noise is barely audible while seated in the chair. You must kneel down to floor level to really hear the fans now. This solution works without compromising access to the machine, or compromising cooling capacity. The T7610 is a true business workstation, with front-to-back only airflow. This 3 sided damping shroud will not work with PCs which have side air intakes, top exhausts, etc. This should be common sense to everyone, but not everyone has common sense, so I'm attempting to head off further "me too" posts. I tend to only reply to thread topics of which I am a subject matter expert. You made the mistake of assuming that a DIY suggestion implies amateur knowledge, then proceeded to display your truly amateur understanding of the subject matter. I don't post to debian-user that often, but there are folks on this list who know they can take the information and analysis I present straight to the bank. They know the level of expertise and analysis that goes into each and every one of my posts, even those in which I don't give the 2-3 page explanation up front, but the short version which assumes the reader knows a little bit about the subject. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/530d8bf3.1080...@hardwarefreak.com
