Over the past 8 years, drone noise levels have shown no improvement

[nswsyw]

I recently upgraded from the Air 3S to the Mavic 4 Pro and noticed a significant increase in noise. This aligns with DJI's official specs, which list the Air 3S at 81 dB and the Mavic 4 Pro at 83 dB. I’m puzzled by some YouTubers claiming the Mavic 4 Pro is quieter—my tests clearly show otherwise. Even at 100 meters altitude flying at moderate speed in a quiet suburban area, the Mavic 4 Pro’s noise is distinctly audible from the ground and noticeably louder than the Air 3S. The supposed "lower frequency" noise of the Mavic 4 Pro doesn’t make it any less intrusive.

Curious about drone noise reduction progress, I purchased a second hand Mavic Pro Platinum to compare with my other drones, testing whether DJI has made any strides in noise control since the Platinum’s release 8 years ago.

Test Method: I conducted tests in my garage, with each drone hovering at 1.2 meters above a landing pad. I measured noise levels using an iPhone app from a fixed position 6.5 meters away, averaging the results over an extended period.

Test Results:

• Mavic Pro Platinum: 70 dB
• Mavic 4 Pro: 72 dB
• Neo: 74 dB
• Mini 4 Pro: 64 dB
• Matrice 4T (default props): 74 dB
• Matrice 4T (low-noise props): 72 dB

The Mavic 4 Pro is consistently 2 dB louder than the Mavic Pro Platinum, a difference clearly perceptible to the human ear. I also found no evidence that the Mavic 4 Pro’s noise is “lower frequency” or more pleasant than the Platinum’s. The Neo’s small propellers produce a particularly harsh, high-pitched noise, making it louder than the Mavic 4 Pro and a staggering 10 times noisier than the Mini 4 Pro. The Mini 4 Pro stands out as one of DJI’s quietest drones, consistently measuring 8 dB lower than the Mavic 4 Pro—a 6.3-fold difference despite being only about a quarter of the Mavic 4 Pro’s weight. This suggests noise may scale non-linearly, increasing faster than weight.

Another observation which might prove this guess: the Matrice 4T is only 160g heavier than the Mavic 4 Pro but produces 2 dB more noise with default propellers. Switching to its bulky low-noise propellers, which reduce flight time, brings it down to the Mavic 4 Pro’s noise level.

Based on my testing method and corroborated by various online video reviews and DJI's published noise ratings, I’ve compiled approximate noise levels for other drones I didn’t test:

• Mavic Pro: ~74 dB
• Mavic 2 Pro/Zoom: ~71 dB
• Mavic 3/3 Pro: ~71 dB
• Air 3/3S: ~70 dB
• Phantom 4: ~82 dB

DJI made significant noise reductions from the 2016 Phantom 4 to the Mavic Pro, followed by another 4 dB drop with the 2017 Mavic Pro Platinum. However, progress stalled afterward, with the Mini 3/4 Pro being the only notable improvement since, achieving a 6 dB reduction. Meanwhile, the Mavic series has seen a gradual noise increase as airframe weight grew. The Air 3S roughly matching the noise level of the similarly sized and weighted Mavic Pro Platinum.

I hope this provides useful insight for others interested in drone noise performance.

 

[Max Headroom]

I like the noise

 

[Rchawks]

My complaint is with the beeping noise from the devices. I just use earplugs before power up as a way to deal with the sound.

 

[Max Headroom]

I like the noise

Joking aside I find the Mini 3 a lot quieter than the Mini 2 someone said the rubber ends on the props make them much quieter.

 

[JeffreyS]

I've seen a linear improvement in sound levels going from the Phantom 4 Pro, Mavic 2 Pro, Mavic 3 Pro and now the Mavic 4 pro. If I don't waste time ascending to altitude, then there's very little chance of bothering anyone.

 

[mavic3usa]

The FPV world of DJI drones are in need of the most help. The NEOs and Avatars are absolutely horrendous. I guess we're not going to get much improvement until the stealth drone becomes a thing.

 

[anotherlab]

The pitch and volume of the sound are determined by the size and width of the propellers and how fast they are spinning. Until someone comes up with a way to keep a drone in the air without props, you are not going to see a "stealth drone".

 

[Gino88]

I recently upgraded from the Air 3S to the Mavic 4 Pro and noticed a significant increase in noise. This aligns with DJI's official specs, which list the Air 3S at 81 dB and the Mavic 4 Pro at 83 dB. I’m puzzled by some YouTubers claiming the Mavic 4 Pro is quieter—my tests clearly show otherwise. Even at 100 meters altitude flying at moderate speed in a quiet suburban area, the Mavic 4 Pro’s noise is distinctly audible from the ground and noticeably louder than the Air 3S. The supposed "lower frequency" noise of the Mavic 4 Pro doesn’t make it any less intrusive.

Curious about drone noise reduction progress, I purchased a second hand Mavic Pro Platinum to compare with my other drones, testing whether DJI has made any strides in noise control since the Platinum’s release 8 years ago.

Test Method: I conducted tests in my garage, with each drone hovering at 1.2 meters above a landing pad. I measured noise levels using an iPhone app from a fixed position 6.5 meters away, averaging the results over an extended period.

Test Results:

• Mavic Pro Platinum: 70 dB
• Mavic 4 Pro: 72 dB
• Neo: 74 dB
• Mini 4 Pro: 64 dB
• Matrice 4T (default props): 74 dB
• Matrice 4T (low-noise props): 72 dB

The Mavic 4 Pro is consistently 2 dB louder than the Mavic Pro Platinum, a difference clearly perceptible to the human ear. I also found no evidence that the Mavic 4 Pro’s noise is “lower frequency” or more pleasant than the Platinum’s. The Neo’s small propellers produce a particularly harsh, high-pitched noise, making it louder than the Mavic 4 Pro and a staggering 10 times noisier than the Mini 4 Pro. The Mini 4 Pro stands out as one of DJI’s quietest drones, consistently measuring 8 dB lower than the Mavic 4 Pro—a 6.3-fold difference despite being only about a quarter of the Mavic 4 Pro’s weight. This suggests noise may scale non-linearly, increasing faster than weight.

Another observation which might prove this guess: the Matrice 4T is only 160g heavier than the Mavic 4 Pro but produces 2 dB more noise with default propellers. Switching to its bulky low-noise propellers, which reduce flight time, brings it down to the Mavic 4 Pro’s noise level.

Based on my testing method and corroborated by various online video reviews and DJI's published noise ratings, I’ve compiled approximate noise levels for other drones I didn’t test:

• Mavic Pro: ~74 dB
• Mavic 2 Pro/Zoom: ~71 dB
• Mavic 3/3 Pro: ~71 dB
• Air 3/3S: ~70 dB
• Phantom 4: ~82 dB

DJI made significant noise reductions from the 2016 Phantom 4 to the Mavic Pro, followed by another 4 dB drop with the 2017 Mavic Pro Platinum. However, progress stalled afterward, with the Mini 3/4 Pro being the only notable improvement since, achieving a 6 dB reduction. Meanwhile, the Mavic series has seen a gradual noise increase as airframe weight grew. The Air 3S roughly matching the noise level of the similarly sized and weighted Mavic Pro Platinum.

I hope this provides useful insight for others interested in drone noise performance.

Wow, I appreciate the work you put into this testing! It paints a clear picture of where we are right now in terms of drone noise production.

In purchasing my Mini 3, a big factor was that it's among the quietest drones out there. I hope we'll see technology progress to the point of making a low sound profile possible with larger drones as well.

 

[hank970]

I haven't compared the noise my Air 3 makes with other drones, but it seems rather quiet to me except up close, at launch. Of course, I'm an old geezer, and my hearing "ain't what it used to was."

I'd imagine that noise relates to the amount of work the drone is doing to climb, accelerate and decelerate, make abrupt changes in direction, and so on. Even when a drone is hovering with the joysticks in neutral positions, there are probably some weird harmonics at play, since the RPMs of individual props are constantly changing to maintain stability in response to changes in wind speed and direction. Are there any physicists or sound engineers among us who could shed light on the subject?

 

[anotherlab]

I haven't compared the noise my Air 3 makes with other drones, but it seems rather quiet to me except up close, at launch. Of course, I'm an old geezer, and my hearing "ain't what it used to was."

I'd imagine that noise relates to the amount of work the drone is doing to climb, accelerate and decelerate, make abrupt changes in direction, and so on. Even when a drone is hovering with the joysticks in neutral positions, there are probably some weird harmonics at play, since the RPMs of individual props are constantly changing to maintain stability in response to changes in wind speed and direction. Are there any physicists or sound engineers among us who could shed light on the subject?

Most of the noise comes from the propellers slicing through the air. The air pressure that creates the lift generates a tonal noise that is the "angry beehive" sound that we all know and love. Changing the angle and width of the blades can change the pitch of the noise. And increasing the RPM of the motors will increase the noise.

As the tips of blades move through the air, vertices or tiny pockets of air are created. This contributes to the noise. Changing the shape and angle of the tips can reduce the sound.

The motors also contribute to the noise, but it's mainly the propellers. The design of the propeller blade, the number of blades, and the rotation speed are the main factors.