Thanks to some Mini 3 Pro noise testing by Youtuber Tech Drone Media I have adapted the chart below to conveniently illustrate where the M3P/M4P fit into the noise spectrum of familiar sounds. Does anyone have other/more scientific data?

Drone noise in context

I compared the loudness of my Mavic Air and the M4P (2m distance):

	Mavic Air	Mini 4 Pro
Propellers are running, drone on the ground	51 dB(A)	51 dB(A)
Drone hovers in 1,5 m heignt	76 db(A)	67 dB(A)

This means that the M4P is about half as loud as the Mavic Air

The Ollie Posted at 2-19 04:24
I compared the loudness of my Mavic Air and the M4P (2m distance):

67 dB is quite a bit louder than the 61 dB measured in the (M3P) test above. Maybe wind noise or other ambient sounds made the difference?

official noise level of Mini 4 Pro as per DJI measurements for C1 classification is 81 dB (same as Air 3): https://support.dji.com/help/con ... Id=34&re=DK&lang=en

trainee Posted at 2-19 04:35
67 dB is quite a bit louder than the 61 dB measured in the (M3P) test above. Maybe wind noise or other ambient sounds made the difference?

I measured it inside, because I didn't  want influences from outside sounds, but so I got reflections from the walls instead.

In summary:
Outside, I always knew where my Mavic Air was.
After a few meters you can hardly hear the M4P anymore.

harweyko Posted at 2-19 04:51
official noise level of Mini 4 Pro as per DJI measurements for C1 classification is 81 dB (same as Air 3): https://support.dji.com/help/con ... Id=34&re=DK&lang=en
[view_image]

WOW. This is probably the maximum volume when you go full throttle in sport mode

harweyko Posted at 2-19 04:51
official noise level of Mini 4 Pro as per DJI measurements for C1 classification is 81 dB (same as Air 3): https://support.dji.com/help/con ... Id=34&re=DK&lang=en
[view_image]

That's good info but 81 dB is presumably the max noise level, ie in Sport mode at full throttle.

The Ollie Posted at 2-19 04:24
I compared the loudness of my Mavic Air and the M4P (2m distance):

Maybe I don't understand this measurement quite right, but the difference between 67dB and 76dB means the Mavic would be eight times noisier, not twice ..

Jan Spacil Posted at 2-19 06:04
Maybe I don't understand this measurement quite right, but the difference between 67dB and 76dB means the Mavic would be eight times noisier, not twice  ..

If you're referring to the power of a signal, you're right, that's 3dB twice as much, so 9dB is eight times.
Psycho acoustics probably behaves a little differently here, there 10bB feels like doubling.

According to my perception, it is actually twice as loud and not 8 times as you suggested.
This also corresponds to the following definition:

Definitions: Sound level or noise level is a physical quantity measured with measuring instruments. Loudness is a psycho-physical sensation perceived by the human auditory perception or the human ear/brain mechanism. That is not the same. We are told by psycho-acousticians that a level 10 dB greater usually means "double the loudness" or "twice as loud". A decibel is one-tenth of a bel, which is the logarithm of the ratio of any two energy-like quantities or two field-like quantities. Ratio doubling means: − a power level of +3 dB, or a sound intensity level of +3 dB − an electric voltage level of +6 dB, or a sound pressure level of +6 dB − a loudness level of about +10 dB −10 dB more SPL means 10 times increase in amplifier (electric) power. In the newsgroups these often misunderstood statements are explained rather less accurately. Decibels can also mean dBSPL or dBA, while a level change is always in dB. The perceived loudness of the sound depends on several factors: the amplitude, the sound pressure level, the frequency, and the time behaviour of the sound. A typical question on the internet: "Is 3 dB or 6 dB double the loudness?" The answer is: "It is neither 3 dB, nor 6 dB − it is closer to 10 dB".

Source reference: Sound technology calculator

I had no idea, it's been many years since we discussed this in school, thanks for the clarification! :]

In practice the Mini 3 Pro is usually audible for me.
Even at 120m.
Until it flies about 50m away, so I know I'm closing in when I start hearing it.

The mini 4 pro sound can't be heard at 150 ft. But the avata that I measured at 111 dB at hover can be heard at 400 ft and up to a block away.

trainee Posted at 2-19 05:01
That's good info but 81 dB is presumably the max noise level, ie in Sport mode at full throttle.

No, this is not the "max" noise. After class change from C0 to C1 DJI Mini 4 Pro is much louder then before change. This should be informed before change. There should be a way to change it back from C1 to C0, because this is misunderstanding.

djiuser_yEvnMfzoKipF Posted at 8-18 11:22
No, this is not the "max" noise. After class change from C0 to C1 DJI Mini 4 Pro is much louder then before change. This should be informed before change. There should be a way to change it back from C1 to C0, because this is misunderstanding.

Some qualification should be provided for this statement, on what basis is the mini 4 louder post C0 declassification?  It is possible use of a plus battery may enable higher prop rotational speed  impacting sound level but I have seen nothing to support this over marginal performance in resisting higher wind speed. Please elaborate.

djiuser_yEvnMfzoKipF Posted at 8-18 11:22
No, this is not the "max" noise. After class change from C0 to C1 DJI Mini 4 Pro is much louder then before change. This should be informed before change. There should be a way to change it back from C1 to C0, because this is misunderstanding.

My M4P is still C0 but I'm sure it seemed quieter after updating firmware this week.

trainee Posted at 8-19 01:59
My M4P is still C0 but I'm sure it seemed quieter after updating firmware this week.

Running master airscrew super stealth so mine usually sounds quiet anyway, not sure it is but definitely a better tone to it.