Actual noise levels

[ShawnK]

Has anyone here ever used a decibel meter to measure the actual noise levels of a gasser heli vs. other nitro birds?

[Tom Fiddler]

Yes I have But I may have been drinking at the time and don't remember the numbers

[WillJames]

Does anyone I fly with have a db meter? Or can someone loan us one so we can check? Between the guys are our club (BSRCC) we have 4 gassers with a variety of mufflers.

[Tom Fiddler]

I have one Will.
I'll be glad to LOAN it to you :D
PM me

[WillJames]

OK we did sound testing today on my Spectra G with TRM Prototype 260 and Hatori Gas Muffler. The guy holding the meter was 9 feet behind the heli, so the outlet on the muffler was pointing straight at him. The heli was on the ground in very short grass. At a fast idle it was 67db and at the same location in I2 at 1760-1800RPM it maxed out at 87db. While the heli was flying the loudest recorded was 70-75db. The things are very easy on the ears. :)

[Laurens]

WOW that means it can fly on our field :mrgreen: . Here its too dark in the evening to measure the sound emission of my Caliber.

[patet]

Hello,
We have to take noise measure within our club in Belgium (unfortunately we do not have so large area to make our flies, the result is that we must have heli with noise lower than 75-78db.) , so I thing this could be great to share it with all of you. I bought first the xcell gaz (+10years ago) and was using the standard mufflers going with the standard zenoah 23cc. 2 years ago I decided to change because it was really noisy. I bought the Zimmermann muffler (2620) the noise was reduce from 84db to 73db (was Great) and the motor was running better. Within the 52 members we have 9 gassers. Most of them use the 23cc with zimmerman, Vario or old Miniature exhaust for the x-cell gaz. Most of the measure was between 72 to 75 db for all 23cc.
All others running 26cc are between 80 to 84 db!. It looks like the 23cc is much quieter than the 26cc! Today after very very... long waiting of the release I have finished to build the Spectra with the H26cc. I am still looking for a quieter exhaust. When I looked at the video with testing 231 or 26cc from toxic or the video of the spectra with the new Hatori muffler, It seems that it not so quite. I decided to test the Torpedo and :arggg: it sounds 83 to 85 db. When I tested the Torpedo in my x-cell gaz in place of the Zimmerman, the torpedo was 2 db noisy (no settings change). I am sure that the Hatori should be quieter than the torpedo, but not enough when using with a 26cc. Now I have decided to test the other zimmermann 2819 and hope that it will sound lower than 79db I will let you know when I will receive it and if it can be fitted to the Spectra without any problem.

When we make the measure, we are 7 meters away from the heli and perpendicular from the exhaust, heli at 1,20 meter from the ground. The motor should run at is max but all we know that it is impossible with heli.

I return the question to all others countries. If we fly for example on Sunday and we are 2 flying in the same time, the measure of the exhaust must be lower than:
75db/heli if the first house is located at 600 meters (our case)
77db/heli if the first house is located at 800 meters
80db/heli if the first house is located at 1000 meters
from the club.
Do you have also so restrictives things in your country ?
I can tell you that it is very difficult to fulfill the law requirements to fly!

Hope this could help someone :)

Patrick

[Laurens]

Hi Patrick,

Here in Holland we have 74 DB for twostroke, which a gasser is. I don't know if you live in the French or Dutch speaking side of Belgium?

[patet]

Hi laurens,

French speaking.

Here is the table for info:

DAY PERIODS (during 9h to 21h mon to sat)
Distance D from houses (meters) Level max à 7 meters* dBA 1 heli -flying - 2 helis flying - 3 helis flying - 4 helis flying - 5 helis flying
200 < D ≤ 300 - 74 71 * * *
300 < D ≤ 400 - 78 75 73 72 71
400 < D ≤ 500 - 81 78 76 75 74
500 < D ≤ 600 - 83 80 78 77 76
600 < D ≤ 800 - 85 82 80 79 78
800 < D ≤ 1000- 86 85 83 82 81
1000 < D- 86 86 84 83 82



TRANSITION'S PERIODE (Sunday and day off)
Distance D from houses (meters) Level max à 7 meters* dBA 1 heli flying - 2 helis flying - 3 helis flying - 4 helis flying - 5 helis flying
200 < D ≤ 300- * * * * *
300 < D ≤ 400- 73 70 * * *
400 < D ≤ 500 - 76 73 71 70 *
500 < D ≤ 600 - 78 75 73 72 71
600 < D ≤ 800 - 80 77 75 74 73
800 < D ≤ 1000- 83 80 78 77 76
1000 < D - 85 82 80 79 78

* not allow to fly

:arggg:

[patet]

The last measure with my spectra and Zimmermann was 76db at 7 meters from the heli, the heli at 1 meter from the grass. I have tried again the torpedo muffler and did not want to measure it because it was really more noisy.

Patrick