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New Propellers and the 4dB improvement
1585 19 2017-9-1
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Mcflying
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So the new propellors will decrease the sound level with 4 dB.
I see posts that it will be a 60% reduction and that sound works logarithmically.

This is all way to technical for me.

So is there anybody out there who can explain the dB improvement in childeren language?
I mean 4 dB increase seems like the difference between dropping a toothpick on a carpet instead of a hair pin.  
  
2017-9-1
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Ex Machina
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Watch and listen to the noise of the Platinum compared to the Phantom for an idea of how much quieter it can be:  https://www.wetalkuav.com/11656-2/

I don't think Mavic owners will get the full 4db/60% reduction benefit due to our older pulse-wave controllers, but any level of quieter would be welcome.

2017-9-1
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Mcflying
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Ex Machina Posted at 2017-9-1 11:39
Watch and listen to the noise of the Platinum compared to the Phantom for an idea of how much quieter it can be:  https://www.wetalkuav.com/11656-2/

I don't think Mavic owners will get the full 4db/60% reduction benefit due to our older pulse-wave controllers, but any level of quieter would be welcome.

oke, i understand 50% but what does the pulse-wave controllers do?
2017-9-1
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Ex Machina
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Mcflying Posted at 2017-9-1 11:44
oke, i understand 50% but what does the pulse-wave controllers do?

So the Mavic controller feeds current to the motors using more of a pulse wave (AKA square wave), and the new controller sends a sine wave. The latter looks like a water wave with smooth ramping sides, resulting in less thrashing of the motor and thus less noise.
2017-9-1
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jamesw
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Ex Machina - you just may be the MVP of this forum. Thanks for being so informative and helpful without any condescension whatsoever.
2017-9-1
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ImHereToCrash
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its little difficult to explain and understand...   

example: 4db improvement on its own actually is meaningless.. because if its 20db to start with and drops to 16db that's barely a change... but if it is 60db and drops to 56db that's a pretty big change.   does it make sense in relative form?  absolutely not!  i dont expect a lot of people to know how it works or how to visualizing it working since again, saying something like 4db change is meaningless without knowing where the baseline value is..

this is why i try to learn both metric and imperial forms of values.. however i dont believe decibels have an imperial form (imperial being the type of measure the US uses), imperial has 1 massive advantage over metric, it is always relative form and most people understand it in my experience, though times do change and im sure i could be wrong now.
2017-9-1
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ImHereToCrash
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jamesw Posted at 2017-9-1 12:17
Ex Machina - you just may be the MVP of this forum. Thanks for being so informative and helpful without any condescension whatsoever.

ya he been around and knows his stuff.  however i think i have mentioned the same thing in another thread on here talking about the new ESC.

one disadvantage with using sine wave over square wave and that is sine wave tends to be less efficient ever so slightly since it is continuous formula, square wave tends to be more efficient since its a time division formula..

example to change speed on square wave: dji probably chops up a standard given voltage and amperage on varying times of on vs off...  

with a sine wave DJi is forced to vary the voltage and amperage while keeping the gates open...  

with sine wave you go get a lot more finesse with how you can tweak and vary things, however you are stuck with gates always open.. the other big advantage of sine wave is that's how nature makes sound thus ts more naturally varied..

advantages of square wave is they get to gate open and closed gates which makes them more efficient, especially true if there is a controller varying voltages and amperage pre-gate..  the switching can be extremely rapid or slower, either are interchangeable depending on the voltage/amperage curve..  the major downside of square waves tend to be they are noisy and sharp sounding because the on and off gates are unnatural..

2017-9-1
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Tombolian
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ImHereToCrash Posted at 2017-9-1 12:48
ya he been around and knows his stuff.  however i think i have mentioned the same thing in another thread on here talking about the new ESC.

one disadvantage with using sine wave over square wave and that is sine wave tends to be less efficient ever so slightly since it is continuous formula, square wave tends to be more efficient since its a time division formula..

Imheretocrash, you clearly need to go back to children's-language class because you're no good at it.
2017-9-1
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gnirtS
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ImHereToCrash Posted at 2017-9-1 12:36
its little difficult to explain and understand...   

example: 4db improvement on its own actually is meaningless.. because if its 20db to start with and drops to 16db that's barely a change... but if it is 60db and drops to 56db that's a pretty big change.   does it make sense in relative form?  absolutely not!  i dont expect a lot of people to know how it works or how to visualizing it working since again, saying something like 4db change is meaningless without knowing where the baseline value is..

That isn't true.  Its an logarithmic scale.  3db is a doubling of *power* regardless.

So in theory 16db instead of 19db is a halving of the power as is 57db from 60db.  Both represent a halving of the power (so volume in this case).  .  So baseline value doesn't matter.  4db is a 60% reduction regardless of base.

However, perceived volume is a different thing altogether.  The ear works differently.  Some studies claim 5-10db is needed for a person to notice a change in volume.  That decibel scale and perceived volume arent directly proportional.

FWIW my main take on the new ESC drivers are it'll improve fine control so enhanced stability as opposed to noise or efficiency changes.  Given normal aerodynamics id expect noise reduction to be almost entirely propellor related as its the prop (especially tips) that produces most of the noise and harmonics.


2017-9-1
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ImHereToCrash
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gnirtS Posted at 2017-9-1 14:55
That isn't true.  Its an logarithmic scale.  3db is a doubling of *power* regardless.

So in theory 16db instead of 19db is a halving of the power as is 57db from 60db.  Both represent a halving of the power (so volume in this case).  .  So baseline value doesn't matter.  4db is a 60% reduction regardless of base.

i mean perceived audio, you are correct.  
2017-9-1
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Franks my Dog
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I think you're absolutely correct; the new props will be carrying most of the load in terms of noise reduction. This rotor design is transferred from full size helis. The designs intent was to produce a more energy efficient, quieter rotor without significantly lowering rotor speeds to potentially dangerous levels. One of the first widespread uses of this design was the British Armed Forces in their Pumas. At the end of the day measurement of rotor noise can be defined mathematically to a high degree. Our ears, however are different from eveyone else's; what may be tolerable for you might be painfully loud for me. In real world use, I doubt many will notice much of a difference
2017-9-1
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ImHereToCrash
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Tombolian Posted at 2017-9-1 13:11
Imheretocrash, you clearly need to go back to children's-language class because you're no good at it.

true i am pretty poor at english,  i apologize for any misunderstandings.
2017-9-1
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Tombolian
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ImHereToCrash Posted at 2017-9-1 17:37
true i am pretty poor at english,  i apologize for any misunderstandings.

I mean no disrespect sir, just poking a bit of fun.  No apology necessary.
2017-9-1
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TheHammer
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Anyway enough with this mumbo jumbo talk, will new wiz bang propellers go Mavic Pro .
2017-9-1
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SadMavic
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A 4db reduction is substantial.  It's more than halving the output level and should be very noticeable.
2017-9-1
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Samoth
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One must read the declaration well: the sound decrease is up to 4 dB. If you look at the graph with the frequency, most of the time, it's barely the same. At start, the new propellers make enven more noise
2017-9-2
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Mcflying
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Oke,........still way to technical.
However with all your text in this post i conclude:

I still cannot sneak up on a deer in the forrest with my the new blades
2017-9-2
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eyecapture
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2017-9-3
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Mcflying
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eyecapture Posted at 2017-9-3 08:01
https://www.youtube.com/watch?v=zVYVWNsCMyE

THANKS!!!!!!! that was what i was looking for.
You hear a real difference in the pitch (if that is the english word for it).

I want those propellors!!!!!!
2017-9-4
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DaViCToRR
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Will the first noise reduction propellars give a db reduction on the regular mavick pro? Or are there other things that factor in on the platinum that helps to do that? I think i read something about the fan that controls the propellars or something....
2017-9-4
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