Props getting louder?

[Xitor]

Read some other prop posts where folks report that they have had good luck with lower noise or stealth props. Understand that some say the sound db level is the same, only the pitch is lower, I'm okay with that. Focal point of my question though is that it seems to be getting louder. Probably only have had this drone for 30 days.

At first I could hardly hear the drone up to about 100 feet, now I can easily hear it all the way up to at least 250 feet and at a good distance. I don't see any prop damage but I'm wondering if it has anything to do with how I'm storing the drone. After purchase I found a few posts where people indicate they just leave the props on, minimizing wear and tear on mechanism that locks the props on, and store the drone in the fly more case. That's what I'm doing and wondering if this is flattening out the props and causing the drone to work harder. Note I'm not using any prop guard / restraint. Also, for anyone else that has purchased newer props which one they recommend for lower noise, perceived noise / pitch.

Thanks!

 

[Jagerbomb52]

Could have something to do with weather and wind. I have the MasterAir Screw Props. Not much better in the noise department.

Why do planes sound louder in cold weather?
Inversions, which occur when the air temperature increases as altitude increases, have the same effect on noise as does cloud cover. These types of weather conditions slow the atmospheric absorption of the noise waves and may cause jet aircraft noise to sound louder.

 

[Meta4]

Focal point of my question though is that it seems to be getting louder.

Your props aren't the issue.
How loud the drone seems is going to vary with how hard the motors are working, the distance away and whether the breeze is bringing the noise toward you or away from you.

 

[Deleted member 103366]

I can't remember but do the ears/brain become adept at picking out sounds, e.g. those made by props?

 

[Xitor]

How loud the drone seems is going to vary with how hard the motors are working, the distance away and whether the breeze is bringing the noise toward you or away from you.

I don't think there is any question that flatter props would result in less lift and require the motors to work harder to achieve the same level of lift. I think the question is if I'm just getting paranoid about how tight the drone is in the case and getting worried about the props getting compressed.

Certainly all you gurus with a lot more experience with this platform (I'm coming from a Phantom 3 Standard where I always removed props), if there was an issue with props getting compressed / flattened in the case I wouldn't be the first one.

I'll assume its other environmentals, but realized that since I have the second set of props that came with the drone I can easily test my current props against the unused ones and answer it definitively. Still they have been getting noticeably louder and higher pitched (wind / weather / whatever) so I think I'll invest in the props Agustine mentioned.

 

[blackbirdsr72]

I always remove the propellers, have not experienced any volume changes at certain distance in comparison to the first flight. I use a nanuk case.

 

[360 Guy]

Save your $$ on stealth props, it not all what it's cracked up to be in my opinion.

 

[careless]

I have Master Airscrew props on my Mavic air 2 and Mavic 2 pro, I can tell the sound difference is a bit louder in the colder weather. I just thought the colder temp's prevent the props from flexing as much.

 

[kerryp24]

You can down load a dB Meter app for you phone and determine the sound levels for yourself.

 

[Jagerbomb52]

I just came in from a flight. 23°F right now. I run the MasterAir Screw props and truthfully I have not noticed much difference in noise level but yes the pitch is lower.
This morning I actually had to search for the drone over my house at 200 feet as I could not hear it as I have in the past. So my conclusion is weather has a big effect on just how loud the props might be for that given day.

 

[PHZ]

You could always buy a set of spare props and compare them under the same conditions. Also, hover and check the rotor RPM and compare them. That should give you some idea of what is happening.

 

[hiflyer201]

At first I could hardly hear the drone up to about 100 feet, now I can easily hear it all the way up to at least 250 feet

I think some people have selective hearing when it comes to so called quiet props, but wind, temperature and the general surrounding noise have a lot to do with what you hear. If you can't hear the Mavic 2 fly overhead in sport mode at maximum altitude you must be in a saw mill.

 

[Xitor]

You could always buy a set of spare props and compare them under the same conditions. Also, hover and check the rotor RPM and compare them. That should give you some idea of what is happening.

That's exactly what I'm going to do! Props that are on now that I guess may be flattened (or not), the second set of props that came with the Air 2S which I never put on, the Amazon 2 sets for $16, and the MAS 1 set for $28. I'll test them all back to back on Monday, or the first day after they come in where I don't have significant wind gusts. Only using the Decibel sound app on my phone, and observation so not super scientific. Also interested in the sound at different distances. Would be interesting to see if I could pull any other data from the logs about RPM, etc to see if there is any impact on performance that could feed their claims (7% longer air time, +2 mph in sport mode, 37% sound reduction. Then I'll know going forward if its worth it or I can save money.

 

[Xitor]

I just came in from a flight. 23°F right now. I run the MasterAir Screw props and truthfully I have not noticed much difference in noise level but yes the pitch is lower.
This morning I actually had to search for the drone over my house at 200 feet as I could not hear it as I have in the past. So my conclusion is weather has a big effect on just how loud the props might be for that given day.

View attachment 138658

More great info, thanks!

 

[MS Coast]

That's exactly what I'm going to do! Props that are on now that I guess may be flattened (or not), the second set of props that came with the Air 2S which I never put on, the Amazon 2 sets for $16, and the MAS 1 set for $28. I'll test them all back to back on Monday, or the first day after they come in where I don't have significant wind gusts. Only using the Decibel sound app on my phone, and observation so not super scientific. Also interested in the sound at different distances. Would be interesting to see if I could pull any other data from the logs about RPM, etc to see if there is any impact on performance that could feed their claims (7% longer air time, +2 mph in sport mode, 37% sound reduction. Then I'll know going forward if its worth it or I can save money.

I've seen some reports on Youtube from people who tried to measure the benefits of those props. As I recall, they all said that the claims were substantially overstated, with the exception of the pitch of the propeller noise being lower - the tone, not the volume.

 

[MS Coast]

You can down load a dB Meter app for you phone and determine the sound levels for yourself.

Sound energy measurements are not simple and straightforward. There are phone apps, but you can't expect definitive, repeatable results, especially when relying on the phone's internal microphones. Accuracy apparently varies greatly between apps. Trying to control variables in comparative flights is going to be a challenge, too.

 

[Crouching Leopard]

Read some other prop posts where folks report that they have had good luck with lower noise or stealth props. Understand that some say the sound db level is the same, only the pitch is lower, I'm okay with that. Focal point of my question though is that it seems to be getting louder. Probably only have had this drone for 30 days.

At first I could hardly hear the drone up to about 100 feet, now I can easily hear it all the way up to at least 250 feet and at a good distance. I don't see any prop damage but I'm wondering if it has anything to do with how I'm storing the drone. After purchase I found a few posts where people indicate they just leave the props on, minimizing wear and tear on mechanism that locks the props on, and store the drone in the fly more case. That's what I'm doing and wondering if this is flattening out the props and causing the drone to work harder. Note I'm not using any prop guard / restraint. Also, for anyone else that has purchased newer props which one they recommend for lower noise, perceived noise / pitch.

Thanks!

Air pressure, time of day (again change in air pressure), wind direction, background noise etc can all have a direct and indirect effect on the actual and perceived noise level. My drones seem to be loud on some days, quiet on others. Also, some drones, like the mini have a higher noise pitch and so are seemingly noisier than my pro. My FPV is even more noticeable.

 

[tlswift58]

I bought the MAS props more for color and hopefully seeing the drone more than for noise abatement. Running both DJI and MAS props - never take them off, only store the drone when carrying it in the Air2 bag I got, and no real issues with more or less noise. I can hear it more when the motors are going hard like in Sport / etc. As for flattening of blades and creating more noise - guess anything is possible.

As others have stated, you'll notice noise more under certain weather conditions - so I'd not go down the rabbit hole thinking your props were getting flatter, so more noise. Props are relatively cheap - both the DJI and MAS and you can change them as often as you can afford or NOT. Prop issues are more in line with nicks and edge damage than flattening and needing replacement.

But your drone, so if you want / need to change the props - then that is up to you if they are not noticeably damaged.

 

[hiflyer201]

There is a road running past my local airport that has a "Musical Street" depending on the wind and direction it becomes downright annoying at times. I've heard it so many times that I automatically change lanes like most others do.

Lancaster, CA - The Musical Road

Visit reports, news, maps, directions and info on The Musical Road in Lancaster, California.

www.roadsideamerica.com