Dear all,
I'm as well an owner of the DS1054Z who is annoyed about the fan noise.
![Banging Head |O](https://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif)
.
After reading several posts, I decided to open my still "virgin" scope to look for a more quiet solution.
All solutions with other fan types are resulting in less air flow and maybe a little bit less noise - I did this as well with an NB XS1 fan.
But this was not what I expected
![Rant :rant:](https://www.eevblog.com/forum/Smileys/default/rant.gif)
.
So I took the long way...
First I measured the audio spectrum (!) in a few assembly states (with the rear sheet metal power supply frame solely, with both metal frames and fully assembled including the rear plastic cover).
These results were quite revealing!
They show that the metal frames are not involved in the "sound" of the scope, but the rear plastic cover, including the grille makes the difference.
![Roll Eyes ::)](https://www.eevblog.com/forum/Smileys/default/rolleyes.gif)
The peaks in the spectrum are at approx. 250...400 Hz.
By knocking on the plastic housing I found that this its resonance frequency
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
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Calculating the fan noise (approx. 3300 rpm @ 8 volts and 7 wings) gives as well 390 Hz. So the fan noise an the housing are in resonance!
With this it is clear that the fan speed must change.
I bought a 60 mm fan (SUNON HA60151V4-000U-999, 2500 rpm @ 12 volt = 1700 rpm @ 8 volts )and tried to bring it into the housing. With some small modifications to the fan - not to the housing
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)
- (space for the rivet and the chamfered edge on the rear) it fits to the metal frame.
In the first stage (as long as there is the warranty) I fixed the fan with double sided tape pads on each corner.
The result is impressive:
Very quiet and still a remarkable airflow
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)
Have fun
kaskade911