Welcome Mavic Pilot!
Jump in and join our free DJI Mavic community today!
Sign up

Is a quiet air-sized drone possible?

pj530i

Member
Joined
Sep 26, 2018
Messages
7
Reaction score
7
Age
35
I'm currently on my first extensive international trip with my mavic air (Albania, nice place) and I am finding the noise to be bad enough that it discourages me from using it. I really don't like annoying other people and this thing's angry bee sound is audible even 400 feet up and hundreds of feet away.

At one spot, a passerby asked "are they always that loud?"

I am using the master air screw v2 props and generally not whipping around in sport mode. Is it just a limitation of physics that props this small have to turn fast and make an annoying sound? I've seen a couple mavic pros here so far and they have much less audibly intrusive.
 
  • Like
Reactions: John32

DanMan32

Well-Known Member
Premium Pilot
Joined
Sep 1, 2018
Messages
3,342
Reaction score
1,143
Age
53
Noise pitch is a big factor in annoyance.
A higher dB but lower pitch may actually be more tolerable than lower dB but higher pitch.

It shouldn't be too costly to have them mass produced.
 

ZX14-R

Well-Known Member
Joined
Jan 20, 2019
Messages
822
Reaction score
406
Location
Brisbane (Northside), Queensland Australia
MP2 over 50m is bout as good as it gets...

More Height - Less Noise. :)
 
  • Like
Reactions: _gonzales_

careless

Member
Joined
Mar 1, 2019
Messages
19
Reaction score
15
Location
KENTUCKY USA.
I use to hear my MP returning from across the river about 1/4 mile out but now with the quiet props I have to watch for it more and it keeps the people playing in the park from being curious.
 

Dave Maine

Well-Known Member
Joined
Jan 27, 2018
Messages
91
Reaction score
44
Age
76
Case example with an Air inDonagal, Ireland square. The square was quite large, with no folks closer than 50 ft from the drone. Took off and was watched by those outside the circle. Interest was evident until 75 - 100 feet when interest was lost.

On landing, no one noticed intil about 60 feet (building Height) when the sound became noticeable and folks looked up. No one was particularly bothered, even when the first heard it, until landing. Staying above 60 feet would have left it unnoticeable.

For clarity, at no time was I directly over any people or vehicles
 
  • Like
Reactions: RonanCork

Cdcolt

Well-Known Member
Joined
Oct 24, 2018
Messages
51
Reaction score
26
Age
68
Location
Lincoln, Nebraska
I'm currently on my first extensive international trip with my mavic air (Albania, nice place) and I am finding the noise to be bad enough that it discourages me from using it. I really don't like annoying other people and this thing's angry bee sound is audible even 400 feet up and hundreds of feet away.

At one spot, a passerby asked "are they always that loud?"

I am using the master air screw v2 props and generally not whipping around in sport mode. Is it just a limitation of physics that props this small have to turn fast and make an annoying sound? I've seen a couple mavic pros here so far and they have much less audibly intrusive.
I understand the concern about noise from the MA. I’m surprised though that you (or others) still find it annoying at “400’ up and hundreds of feet away”. My MA with the Master Airscrew v2 props is barely audible at 200’ overhead. I live and fly in a suburban area that is fairly quiet although not as quiet as say a hike in a mountainous area away from civilization. I too chose the MA because of its size and comparably good performance as I intend to have it with me on wilderness bike rides. A larger drone wouldn’t work for me.
 
  • Like
Reactions: pj530i

pj530i

Member
Joined
Sep 26, 2018
Messages
7
Reaction score
7
Age
35
I understand the concern about noise from the MA. I’m surprised though that you (or others) still find it annoying at “400’ up and hundreds of feet away”. My MA with the Master Airscrew v2 props is barely audible at 200’ overhead. I live and fly in a suburban area that is fairly quiet although not as quiet as say a hike in a mountainous area away from civilization. I too chose the MA because of its size and comparably good performance as I intend to have it with me on wilderness bike rides. A larger drone wouldn’t work for me.
I can't say when it's annoying to other people but to me, almost any time I hear it I feel that it's possible someone is annoyed. A couple hours ago I flew it around a big castle and could clearly hear it when the display indicated that it was 400 feet up and 700 feet out. Maybe this is just a particularly quiet country...

Tomorrow I will switch back to stock props and see if maybe my master airscrews are screwed up.
 

EmailGuy

Member
Joined
Apr 5, 2019
Messages
7
Reaction score
13
It's basic physics. You have to generate more lift than the weight of the drone. If you are pushing enough air to lift a drone the weight of the Mavic Air, it's going to make a certain amount of sound. The solution to a quieter drone would be to make them lighter. So the key would be to use batteries with more capacity per unit of weight. As battery technology improves they can use lighter batteries and smaller motors/props. that will allow them to make a quieter drone.

I've custom built many drones. You can get small improvements by using larger props with less of a pitch. You do sacrifice performance. The larger props cannot react as quickly to changes like a little wind or to compensate for tilting. That also requires longer arms on the drone to spread the motors farther apart to be able to use the larger props. That is while the Mavic Pro is quieter than the Air. It has larger props spread farther apart.
 

quirom

Well-Known Member
Joined
Jul 22, 2019
Messages
84
Reaction score
34
Age
30
Solution: fly in noisy places, people will never realize your drone is nearby.
 
  • Like
Reactions: _gonzales_

Hummingbird.UAV

Well-Known Member
Premium Pilot
Joined
Jul 3, 2019
Messages
106
Reaction score
157
Location
Fort Saskatchewan Alberta
Site
www.youtube.com
It's basic physics. You have to generate more lift than the weight of the drone. If you are pushing enough air to lift a drone the weight of the Mavic Air, it's going to make a certain amount of sound. The solution to a quieter drone would be to make them lighter. So the key would be to use batteries with more capacity per unit of weight. As battery technology improves they can use lighter batteries and smaller motors/props. that will allow them to make a quieter drone.

I've custom built many drones. You can get small improvements by using larger props with less of a pitch. You do sacrifice performance. The larger props cannot react as quickly to changes like a little wind or to compensate for tilting. That also requires longer arms on the drone to spread the motors farther apart to be able to use the larger props. That is while the Mavic Pro is quieter than the Air. It has larger props spread farther apart.
Your basic physics is right however much of the noise is generated by the shape of the blade tip. A square tip like on the MA generates a noisy tip vortex. Quiet blades have tip modifications to reduce the tip vortex thus lowering the noise. Just look at the DJI low noise props for the Phantom and Mavic Pros. The Anafi blades I used in my props also have a modified tip. However the Master Airscrew silent props DON'T have this feature, they are square tipped. They have higher pitched blades which reduce the motor rpm thus making them quieter and lowering the high frequency buzz.
 

EmailGuy

Member
Joined
Apr 5, 2019
Messages
7
Reaction score
13
Your basic physics is right however much of the noise is generated by the shape of the blade tip. A square tip like on the MA generates a noisy tip vortex. Quiet blades have tip modifications to reduce the tip vortex thus lowering the noise. Just look at the DJI low noise props for the Phantom and Mavic Pros. The Anafi blades I used in my props also have a modified tip. However the Master Airscrew silent props DON'T have this feature, they are square tipped. They have higher pitched blades which reduce the motor rpm thus making them quieter and lowering the high frequency buzz.
I also have a Mavic 2 Pro which comes with the "low noise" props standard. It still makes a considerable amount of noise. I do agree that prop design has an effect on the noise, but that alone can only go so far. The real solution is to make a super light drone. To carry a 4K camera and a gimbal will mean everything will need to get lighter.
 

DaleB

Member
Joined
Jul 24, 2017
Messages
12
Reaction score
3
Age
64
I can't say when it's annoying to other people but to me, almost any time I hear it I feel that it's possible someone is annoyed. A couple hours ago I flew it around a big castle and could clearly hear it when the display indicated that it was 400 feet up and 700 feet out. Maybe this is just a particularly quiet country...

Tomorrow I will switch back to stock props and see if maybe my master airscrews are screwed up.
The castle (as any rock or concrete structure tends to do) may have been acting as a sonic reflector. There's an old fort near where I live, and they often host concerts on the grass 500 feet away. There's an easily heard second reflection. In other words, not only might you have been hearing the original sound of the drone, the 'noise' may have been made worse with added reflections.
 
  • Like
Reactions: pj530i

jason38

Well-Known Member
Joined
Dec 31, 2017
Messages
214
Reaction score
140
Location
Isere, France
A little bit longer , but a little bit less thick than the air when folded...also lot quieter!
 

Hummingbird.UAV

Well-Known Member
Premium Pilot
Joined
Jul 3, 2019
Messages
106
Reaction score
157
Location
Fort Saskatchewan Alberta
Site
www.youtube.com
A little bit longer , but a little bit less thick than the air when folded...also lot quieter!
Is there a place where I could buy replacement screws to hold the blades on? I have not been able to find any.
 

jason38

Well-Known Member
Joined
Dec 31, 2017
Messages
214
Reaction score
140
Location
Isere, France

New Threads

Forum statistics

Threads
70,694
Messages
818,690
Members
97,830
Latest member
lrdahlberg