My two month old HTPC build has recorded over 150 hours of television so far and performed flawlessly. Looking back, it was a solid build but it is slightly louder than I would like. This Friday night I decided it was time to make this HTPC the first member of my Decibel Reduction Program (DRP). Read on to find out more about the DRP and how this HTPC went on a sound diet!
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Background
Back in August I built a small HTPC to record all of my television. That article is at:
https://moviesgamesandtech.com/2010/08/16/building-an-under-cabinet-htpc-on-a-friday-night/
It was a easy build since I was using a recycled 3.5” drive, OEM cooling solution and the included power supply. It pulled 50-60 watts under load and the dual core CPU was more than enough to record multiple shows at once. The build was small and cheap. So what was the issue? It was loud for a HTPC.
Ok, it probably was not that loud but it was still loud enough to hear the fan and drive when you walked by the room. I decided to start my new Decibel Reduction Program (DRP) and see how low I could get the sound. I also plan to go over my other PCs and see what cooling solutions I can find to lower the sound impact in my home.
I found a cheap decibel meter online at Amazon and decided to check how loud the HTPC actually was.
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The Decibel and You
A decibel (dB) is a way to measure the power of sound. Each decibel integer increase is one times as loud, so a sound that is at 60 decibels is 10 times more powerful than a 50 decibel sound. Without having a frame of reference and a calculator it is hard to explain so I will leave the whole decibel definition and measuring for one of my BYOB sermons.
Let us look at a few common sound levels as a reference. You would think that the scale would start near zero but realistic sound in our daily life starts above 20 dB.
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Common Decibel Levels (non-scientific)
28 dB – Inside a closet in center of house (at night) with a beer and a flashlight
30 dB – Sleeping wife
36 dB – Bamboo growing in a quiet room on a Friday night with AC on and vent open
43 dB – Netbook running Windows Updates
44 dB – EX485 with four WD Caviar Black drives (in Ikea cabinet)
53 dB – EX485 with four WD Caviar Black drives (cabinet open)
56 dB – HTPC recording television
58 dB – Dave McCabe talking
60 dB – Dishwasher
65 dB – Diehard talking
68 dB – Dishwasher after a couple of glasses of wine
70 dB – Engine noise inside your truck while getting on the freeway
80dB – Inside an airplane just behind the exit rows in flight
85 dB – Moderate Surround Sound during intro to Saving Private Ryan
90 dB – Standing on the side of the freeway listening to the truck get on the freeway
110 dB – Jet engine from that parking spot at the end of the runway
120 dB – Vuvuzela
130 dB – Glock 17 fired at arms length
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Some Quick dB Readings
Nice upgrade Tim, thanks.
TIM – I'm really missing the "Let's set this pig on fire". BTW, good move on listing the sleeping wife lower than Dave McCabe's voice.
DVN pointed out that I'm louder than a dishwasher 🙁
i love those pico psu 1 have a couple of them already they help alot.
my next pico psu will be going into my HP EX470 what do you think? good idea
What wattage draw do you get from your EX470? I would only suggest changing PSUs if you had one that was bad. Or of course you wanted to just play! 😉
i forget, i would have to throw the killa watt on it again.
The pico i like using is the 150 with the 150 block.
i changed the factory psu once already, it died after the first year.
but in the name of (DRP) i might just give it a try 🙂
I would think that the Pico type PSU would be a viable alternative to finding a replacement PSU on the EX series. I am not sure if you could remove the old PSU, as it seems integrated into the mounting on the EX series. I guess you could just unplug it and leave it under the mobo. I would also see if the 150 rating is the actual output of the Pico.
Tim – a few useful – official Sound references (IT) you may wish to review :
http://silent.se/iso-9296.php
When we had our PCs tested the (very official) results were staggering :
ISO7779 (clause 6.10) LWA = 27.3
A weighted Power Level
This converts to approx 13.5dB @ 1M The sound pressure @ 1M
(Domestic 'sound meters' tend to start to work around >30dBA – so are useless in the sound zone we work in – an interesting point – when I attended some of the chamber tests, it was not only weird but painful, as the test chambers are near zero dBA – that means your ear drums actually move 'out' as typically they are always 'under ambient pressure) – causing pain (so much for silence is golden)
Measuring sound is always going to difficult outside of ETL. We have a complete Acoustic Noise Test Procedure where I work. While I am not an engineer, I do appreciate all of the work that goes into testing the equipment. They pump down with gas and calibrate the consoles and microphones with amazing accuracy to the microbar level. The little cheapie meter I bought was just to try out and I was not even being consistent with the measured distance. Did I mention the beverages?
I am surprised they let you in the chamber during testing (must be different testing of course) but I bet it was cool to feel complete silence!
so much for hearing ringing in my ears
haha