Checking Fan Noise and Other Sound Levels with Benetech GM1352 Sound Level Meter

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I wrote about UNI-T UT353 Sound Level Meter a few month ago as I thought it could be a neat way to measure fan noise on some TV boxes and mini PCs in an objective way. I finally ended up buying Benetech GM1352 model instead for $13.9 on DX, but I did not really use so far, since I did not get a new device with fan. I’ve now had the chance to try it as Voyo VMac Mini comes with a fan.

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Let’s just go through some of GM1352’s key features first:

  • Noise Levels & Accuracy – 30 to 130 dB with +/- 1.5 dB accuracy (94dB @ 1 KHz)
  • Frequency Range – 31.5 to 8 KHz
  • Measurement features – MAX/MIN & Data hold
  • Display – 1.7″ LCD display with backlight
  • Buttons – Power/Backlight, MAX/MIN/Normal selection, HOLD
  • Power Supply – 3x AAA batteries (included)
  • Dimensions – 15.7 cm x 5 cm x 2.8 cm
  • Weight – 81 grams

Now that we got that out of the way, I’ve done some measurements inside a quiet room, with fans, an airplane flying over my house, etc… When possible, I placed the microphone two to three centimeters from the noise source.

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Here are the results of my little experiment.

Noise Level (dBA)
“Silence” 38
Voyo Vmac Mini 52.3
Tower PC idle 58
Tower PC high load 67.5
Plane over the house 68
Whispering 71
Running Tap Water 86

My main PC is really noisy, so if you have numbers in the 58 dBA range with the mic at 2 to 3 cm from the fan, it’s already pretty loud. Voyo VMac Mini fan is much quieter, but at 50.2 dBA, it will still annoy some people, although it does not run all the time. It’s a little noisier than the fan on Beelink BT7 mini PC, which I found to be pretty quiet, but some people found it really loud.

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tkaiser
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tkaiser

Isn’t the device able to produce reasonable readings? Avoiding dB and use Sone instead?

tkaiser
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tkaiser

@cnxsoft
Well, I question the results due to Decibel being a logarithmic unit and impractical measurements — too close. But since people love numbers your readers might be happy anyway 😉

Since not only me but a lot of our customers hate noise and you show a Mini PC above… we’ve made some experiences with reducing noise originating from Mac Minis. Every new generation has a more sophisticated fan built in but under permanent heavy load the fan gets active and can be annoying… when placed on the table. Using VESA mounts and placing it behind the display is a nice solution as long as no others have to work behind the display. By mounting these devices under the table using special equipment (in fact pieces of carpet) they become almost silent.

At least customer’s users report that it’s not ‘noisy’ any more even under worst case conditions. But it took some time to get the idea how to choose the various distances of the surrounding to not negatively impact heat dissipation (especially to allow the Mini to run as long as possible without starting the fan)

Theguyuk
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Theguyuk

Noise is a odd one because it can be more than the fan. A small box with fan can transfer vibration to the surface it is on. Also accustic echo

As you know, rubber feet can help a little or sitting it on some types of mouse mat or cork coaster. Do not onstruct air flow either. Consider the fire risk.

In a office health and safety, fire standards apply.

A good free air flow works wonders as does keeping it clean of dust.

When I worked in government offices most problems were bad enviroment design and bad airflow in and around the device lack of airflow often created hot spots around the tower, desktop, all in one PCs, printers, copier and Fax machines. Heat and paper clips were the biggest pain. Got sick of fixing jammed copiers and Xerox where always breaking down.

Have you seen inside the new 2nd generation Nvidia shield TV? I don’t own one but the topic of, whats the noise like from 2nd gen Nvidia Shield TV fan has been raised elsewhere.

Here is inside 2nd generation shield TV
http://www.aftvnews.com/partial-teardown-of-2nd-gen-nvidia-shield-tv/

I would suggest CNX you ask your readers what they consider good noise test distance to viewing distance. Like you mention it is so subjective.

Many offices even put the computer in a strong security cage if sensative data or risk of theft is a worry, in my experience in UK.

NIPSZX
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NIPSZX

My MacBook Pro would damage that unit because the fans run so loud!