Enclosure vs. Paving Stones: Measuring Prusa MK3S 3D Printer Noise

First, I'll just say off the bat that we welcome and encourage customers to DIY whatever setup they want, and we will gladly give advice on how to achieve those goals with our enclosures. There have been some forum posts advising to use paver stones to cut down the noise from a 3D printer and improve print quality, which begs the question: do paver stones work and how does that compare to the noise improvement from putting a printer in a 3D UP Fitters enclosure?

We support a couple of dozen different types of 3D printers and actually use them to print, so I was fairly surprised to see Prusa users as being the ones talking most about noise reduction.  The Prusa MK3S is already one of the quietest printers you can buy!  Not only is it quiet compared to other 3D printers, but it even has a built-in "stealth mode" that makes it even quieter.  In fact, the MK3S is likely to be the quietest appliance in your house

Unenclosed Prusa MK3S Loudness Comparison

To see what all the fuss was about we measured an unenclosed Prusa MK3S with the stock rubber feet on one of our favorite tables, both in normal and stealth mode sitting right on the table and then on a 16x16 35 lb paver stone using two separate noise meters. The 3D model used was the classic "benchy".  The MK3S is so quiet we had to wait until geese flying overhead passed to get an accurate reading. 

Although we didn't test every printer in the office, the Prusa MK3S is by obviously far the quietest printer we use every day, especially compared to the Creality line. Not only did the stealth mode work well, but it made the printer slighter quieter than when on the paving stone!  You have to give up crash detection with stealth mode turned on, but the return on investment with not having to lug a 35 lb paving stone from the hardware store is pretty large.  

Once the printer is on a paving stone then stealth mode doesn't seem to make a difference. Note that the scale of the chart is based on the context of the normal sound level in an office or home.  One poor use of informational graphics is to put just two values on a chart.  This practice exaggerates the difference and gives a false impression that the two numbers are far apart. This chart places the values in context so you accurately compare the measured values to sound levels you may be familiar with.

Enclosed Prusa MK3S Loudness Comparison

But what happens when you enclose a printer?  First, understand that sound reduction was not the primary design goal at 3D UP Fitters; air quality and printer temperature management are the main goals.  Never-the-less, putting one of our acrylic enclosures around the MK3S dropped the noise level 5.5db below that of an unenclosed MK3S on the table and 2.5dB less than the MK3S on a paving stone.  

Adding a paver stone to an enclosed Prusa MK3S reduced the noise further by about 2.5dB, which was not obviously perceived during the test. Turning stealth mode on and off while enclosed didn't vary the noise level by a measurable amount.

It's interesting how an enclosed Prusa is so close in loudness to having the printer simply turned off.  These measurements were taken in a quiet suburb and the ambient noise of a quiet house was very close perceptually to that of the Prusa printing while enclosed. 

Print Quality

The other supposed benefit from the paving stones is print quality. The problem with measuring print quality is there is no objective way of doing that. Sure, you can print some standard calibration patterns like benchy and eyeball the difference, but that's not an engineering best practice. I didn't see any difference in print quality in the Benchy prints, but other people said they saw a difference so your mileage may vary.

Part of the quality issue is you theoretically could get some small benefit if you were trying to run your Prusa at top speed, but our philosophy is to not run the printers as quickly as possible.  Instead, we try to find the best balance of layer height and density for each part that gives the best possible combination of strength and print quality while running at a print speed known to produce the best quality.  

Conclusion

If your Prusa isn’t enclosed then adding a paver stone underneath does make a small audible difference if you don’t want to use stealth mode.  I won't be adding them to my printers at home since the enclosed Prusa printers are already way quieter than the other printers I run overnight.  

Anecdotally, the people who've complained about loudness with the Prusa seem to be using wooden tables. There's a reason speaker cabinets and guitars are made out of wood:  they resonate and amplify sound so well. My gut reaction is you'd see a bigger difference switching tables than adding a paving stone, but that's just a guess, though, and something for future research to confirm or deny.

If your printer is enclosed then at least in my opinion a paving stone isn't needed since there's only a nominal noise reduction. But if you want to add paving stones to your 3D UP Fitters Prusa enclosure, no problem, you'll need to print this user-designed riser so that the enclosure is at the right height.