Hey, this is Andrew from djibestdrones.com and today I’d like to dive a little bit deeper into the engineering behind the changes that DJI has incorporated into the brand new Phantom 4 Pro version 2.0 compared to its predecessor Phantom 4 Pro.
|Model||DJI Phantom 4 Pro v2.0|
|Diagonal Size||13 inches|
|Weight with Battery and Propellers||3 lbs|
|Camera||1” CMOS; 20 MP; C4K (H.264) 4096×2160 24/25/30/48/50/60p|
|Hover Time||30 minutes|
|Range||up to 5-6 miles, depends on weather & terrain conditions|
If you remember their announcement there were three fundamental upgrades they made to this brand-new quad that are different from the original. The first has to do with the propeller system: DJI has completely redesigned their propellers from the ground up to make this quad quieter and more efficient when it’s flying. The second change they made was upgrading the ESC or electronic speed controls from a square wave pulse to a sinusoidal driven ESC and, again, that should help with the efficiency and make it a little quieter when it’s flying. It should also improve the flight characteristics and make it a little bit smoother when you’re on those joysticks. The third change involves the connection topology between your remote control in the quad: they move from LightBridge to OcuSync which is similar to what they used on the Mavic Pro and again that should have a big impact on how that quad flies.
Now I want to focus on the propeller system because even though this seems like a simple and small change to the quad the engineering behind this is incredibly difficult; the aeronautics behind it and the way you make these props more efficient involves a ton of engineering and a ton of testing production molds have to be changed. It seems like a simple change but it has a big impact on how that quad flies and honestly the question I get from you guys more often than any about this brand new quad “Is the Phantom 4 Pro version 2.0 quieter than the original?” and also “Can I use the props on my Phantom 4 Pro v.2.0 from the previous model?”. I will try to answer that question as completely as I can.
I’m going to split the answer into four sections: this first section of just introducing things, the next section is going to be why these props are different from a physics perspective and what changes they made and how it impacts the way the quad flies. The third section after that I’ll put the two quads up the Phantom 4 Pro version 1 and a Phantom 4 Pro version 2. Then in the final section I’ll do a conclusion and explain to you why I think even though it’s not much quieter I think it’s a lot more pleasant and I’ll explain that little detail in the conclusion.
Engineering Behind the New Props
I’m not a big fan of marketing where people will come out and tell you to do certain things I need to see it for myself I need to test it and then I want to relate that to you guys so you can understand why this new quad is really such a big deal.
So anyway hang on and I’ll get into it the science behind flight is an interesting and pretty complex topic that’s helped aeronautical engineers make a really good living designing and refining propellers just like this but even so it really boils down to two concepts in physics that are pretty straightforward. The first has to do with controlling how air travels across the fixed airplane wing or in this case a propeller and by controlling how that air travels across that surface you can create a low-pressure system above that wing and a high-pressure system below that wing.
That does two things for you that are beneficial: the first is the wind can push down on the high pressure system below it while simultaneously being pulled into that low-pressure system above it. There are a couple of different factors that affect how efficient a wing is to create that imbalance: if you will between the high in the low pressure system. The first has to do with the length of the wing whereas the second has to do with the shape of the wing – how wide it is and the third has to do with the curvature. And if you look closely at these two propellers three major changes have been made to the propellers that really impact that efficiency.
The first one is when I put them side-by-side and I’ll do blow-ups of these you can see that the new propellers are much wider so that means it’s got a longer distance to travel in the years traversing the top or the bottom of that wing. The second thing they did was increase the curvature on the bottom so down here I’ve got a much more pronounced curvature to the new wings than I do in the old ones it also has a little bit slider tilt when you look at it against its axis. And the third thing which is the first thing you’re probably going to notice is the end is different. In the original propellers I’ve got a blunt end here on this new propeller I’ve got what’s called a swept back or a rake back wing tip on the end of it.
That seems like a small adjustment but it has a huge impact on how efficient this blade is and how much noise it generates because while this is spinning through the air you’re gonna have a low-pressure system above it and a high pressure system underneath it. Those are going to meet at the back of the wing so you’re gonna get noise back there and turbulence back there but it’s even more pronounced at the tip because these are going to slide off the end of the wing and they’re going to meet out here and it’s going to create this vortex of high pressure and low pressure equalization which is bad for two reasons. Number one: a vortex is noisy so it’s creating a lot of noises, it’s chopping through the air. The second thing is because that’s an imbalance and pressure out there the wing has to fight its way through that vortex which makes it very inefficient by having this little design right here it allows that wing as it traverses through the air to have those unequal or imbalanced pressures slide off the back of that wingtip. Therefore they’re gonna actually meet at the back of that wingtip and it’s a much more gentle introduction for those two to meet which means I have less of a vortex less noise and have less to fight tourism.
The other thing is the additional width of the new propellers. DJI thinks about things like harmonics because as this travels through the air it’s going to vibrate slightly and this one will vibrate at a different frequency. They are basically complementary noise or frequencies that amplify each other so it’s a much more pronounced combination of those frequencies than it would be for any individual frequency and when I put these through the test later and run it through a spectrum analyzer I’ll show you those individual frequencies and you’ll notice that on the new blade not only are there less of them but there are less pronounced. In the end you’ve not only got less frequencies that are being generated by this blade but they’re less loud.
To sum up this section:
- The first thing is the length of those propellers are pretty much identical from the hub to the end point;
- Another thing that becomes apparent pretty quickly is the width of the DJI Phantom 4 Pro V2 propeller is much more substantial not only at the base but throughout its entire length;
- Better shape of the Phantom 4 Pro V2 props allow it to fly quitter and smoother.
So that’s a major design change between these two and very similar to what they did in the Mavic Pro Platinum as well which did decrease the amount of noise and increase the efficiency of that blade set as well. All together this is a big change in props and I know it seems like a small thing but when you think about the prop design the amount of hours that go into designing the props, testing the props, manufacturing them it’s a different mold in this one. These are specially built for that Phantom 4 Pro v2.0 for its weight characteristics and its flight parameters, all that comes into play. So the fact that they came up with an entirely new propeller design to increase the efficiency and lower the noise on this is extremely impressive to me.
I’m also with the field test to show you just how much quieter the brand-new DJI Phantom 4 Pro version 2 is when compared to the original. To set up the test I’ve got a Phantom 4 Pro version 2 on my left and a Phantom 4 Pro version 1 on my right what I’d like to do is point the camera straight up I’ve got a shotgun mic mounted on it I’ll fly both quads directly over the camera first at 50 feet then at 100 feet and I’ll record the audio. The reason I don’t use a DB meter is I find that you’ll pick up a lot of extra strain always when you’re outside and it really doesn’t give you a clean test by recording the audio I can run that through a spectrum analyzer and give you a visualization of what the noise profile looks like and it’s really easy to look at side-by-side comparisons between the two and see what frequencies are in there.
I’ll fly the DJI Phantom 4 Pro v 2.0 first with the new low noise props and I’ll fly the original Phantom 4 Pro with the original props then I’ll switch the props and I’ll fly the brand-new quad with the original props and I’ll fly the version 1 with the new low noise props and we’ll see what kind of difference it makes. I expect that the version 1 will be quieter with these new low noise props but I believe that the sinusoidal ESC’s that are part of the upgrade contribute to that low noise profile as well so it’ll be interesting to see how that plays out.
I hope that series of audio clips helped you to hear the difference in noise levels between the two quads flying at 50 feet and a hundred feet. Now just to remind you on the Phantom 4 Pro version 2 I was using the new blades and on the Phantom 4 Pro version 1 I had the original blades on there. Listening to it both in the studio and out there in the field to my ear it seemed like the version 2 had a lot less high frequency whistling going on with that quad and it seemed like the lower frequencies were amplified a little bit so in general I think it was a much more pleasant tone with the version 2 over the version 1 but I’ll leave you guys to decide for yourself.
The next section is going to get really interesting because what I thought I would do is drop both of the quads down to a 25 foot level. I want to bring it down so far is because I want to get it as close as I can to the mic to capture the biggest amount of noise profile so when I run it through the spectrum analyzer a little bit later I can compare the two side-by-side once I get that base level set and I’ll show you exactly what they sound like at 25 feet.
I’ll flip the props and I’ll put the brand-new props on the version 1 quad I’ll fly it again and I’ll show you the sound between the version 1 with the new props and the version 1 with the old props and that way you can hear if these props make a difference and how much of a difference they actually make. Then I’ll give you the base level comparison of the version 1 at 25 feet with the original props and the version 2 at 25 feet with the new props and you can see the difference even closer to the mic.
Okay now to my ear that sounded a lot more dramatic so the closer got to the microphone I could actually pick out the fact that all those high-frequency sounds were gone and I definitely hear a much lower and in some ways more pleasant sound coming out of the Phantom 4 Pro version 2. So now what I’d like to do is flip those blades between them and I’m gonna put the brand-new blades on the version one quad and then put it back up. I let you do a side-by-side comparison between the version one flying with the original props and the version one flying with the brand-new Phantom 4 Pro version two props and let’s see if they make a difference.
I have to say that I was pretty surprised by those result I really expected to take the version two props put them on the version one Phantom 4 Pro and haven’t knocked down the noise somewhat. But when I put that quad up with these new props on it to my ear it was like 50% of the noise was gone and again I keep talking about that high frequency annoying portion of the noise spectrum and that seemed to have disappeared completely so I was very impressed with the difference it made.
I’ve recorded all that audio to run it all through a spectrum analyzer and we can get a look at exactly what the differences are.
A spectrum analyzer is a device that will listen to an audio file digitally and it’ll process that audio file and present you with a visual representation of what composes that audio file. It will show you the frequencies and the amplitude of those frequencies inside the file you’re listening to. Why I liked it so much is because even though your ears are a good measure of how loud something is looking at the spectral analysis of an audio file really gives you a feel for what frequencies are in there and how loud they are and then I can put them side-by-side.
In this first spectral analysis I’ve got the Phantom 4 Pro version 1 on the left and the Phantom 4 Pro version 2 on the right. If you look at the spectral analysis side-by-side you can see that a lot of the frequencies are the same between the two but if you look carefully on the right with the new props you’ll notice a lot of the red especially around that 1.5 kilohertz is disappearing so what they’ve done there is essentially eliminate a lot of those frequencies right around that one and a half kilohertz range to make it a little bit quieter in that frequency spectrum. And that seems to be a frequency that a lot of people respond to as a fairly annoying frequency. So at the 50 foot level they’re doing a pretty good job of eliminating annoying noise.
Now we’re looking at the hundred-foot elevation and again I’ve got the Phantom 4 Pro v1 on the left and the Phantom 4 Pro v2 on the right and you can see immediately that that right hand representation has a lot less frequencies present which means those are missing which is a good thing. It also shows you that down in the lower spectrum around the 70 Hertz range it’s almost completely attenuated things really down on the bottom end of that spectrum. There is one little tiny band of red that runs through there but again that’s not in a frequency band that most people find annoying so that’s a pretty impressive difference. And that seems to be the height that most people fly out their drones so in that case that Phantom 4 Pro version 2 really makes a difference with those new props.
This last chart is at a 25 foot elevation and I’m comparing the Phantom Pro V1 on the left-hand side with the original props against the exact same quad on the right-hand side with the new low noise version 2 props. When you look at that right-hand chart you can see right away that they’ve eliminated pretty much all the annoying frequencies above the 5 point 5 kilohertz range and even down the bottom where you’ve got frequencies at pretty good amplitude around the hundred Hertz range. That frequencies not that annoying but when you get above that .5 kilohertz range that’s where people start noticing things and are annoyed by frequencies in that range. Almost everything above that has either been eliminated with the new props or at least been attenuated to where it’s not an annoying level that most people would complain about. This is really comforting because when I listen to those 2 quads side by side to my ear I could definitely hear a difference but somehow seeing it visually like this really proves the point and really brings the point home that those new props are really helping to lower that annoying frequency at the top end of that band above that 1.5 kilohertz.
I hope you guys enjoyed that section and I know I may have wandered way out in a nerd territory with a lot of the detail I gave you there but for me it’s important I give you as much information as I can to help you make the right decision on this new quad that’s just been released. From listening to it is probably a gut reaction that most people are going to have and you’ll make a decision based on what you hear and which one you think sounds quieter but somehow for me having that detail on paper that I can look and compare the two side-by-side really brings that point home for me. So hopefully it was helpful for you guys.
Now I’m going to get into the conclusion section next and I’ll give you some idea of what I think makes the difference between the two and maybe some recommendations on what you should do moving forward if you own the original DJI Phantom 4 Pro or if you’re considering the Phantom 4 Pro V2.
Pros And Cons
In this last section I’d like to wrap things up by providing some of my own personal hands-on experience and opinions on how these props really improve the flying experience for the new Phantom 4 Pro version 2.0.
I’ve been very lucky that I’ve had the quad for the last couple of weeks and I’ve been flying it non-stop ever since it arrived if it hasn’t been pouring rain outside. I’ve had this thing out in the field and up in the air and I’ve taken it to a bunch of different locations: I’ve flown it at the beach in the woods and rural locations on sunny days, cloudy days, windy days and I’ve been careful to bring along a Phantom 4 Pro version one with me so I could put both quads up under the exact same conditions to do a fair side-by-side.
If I look at all the evidence that I’ve collected on these new props versus the version one it brings me to the conclusion that I think is almost unavoidable that DJI Phantom 4 Pro v2.0 is quieter than the Phantom 4 and the honest answer is yes it is but more importantly it’s less annoying which is really what counts for me because intensity of the sound is one thing but having an annoying sound even if it’s a lower decibel level it is way more attractive I think.
I did a couple of anecdotal tests as well: when I put this thing up in the air around other people I would say to them very simply “I’m gonna put one up, put another one up and you tell me which one you hate the most, which one’s making too much noise for you to put up with”. The version one was the one they picked every time about being the most annoying and again if you look at the spectral analysis it gives you a clear impression that those brilliant design engineers at DJI built the prop that eliminated a lot of the higher frequencies and attenuated the lower frequencies so the Phantom series became much quieter.
I found that Phantom 4 Pro v2.0 had a smoother flight and it seemed like it would accelerate smoother going to a turn and back, smoother elevating, descending was smoother. So I think to my mind it not only improved the audio quality of the quad but it made it a much more pleasant flight for me.
As for the camera quality I recommend you to check my Phantom 4 Pro review as the V2 camera has the same specifications as the original one and they both are quite similar except for the differences which we discus in this review.
So if you are looking for the professional flying quadcopter with camera that won’t scare the people away the new DJI Phantom 4 Pro v 2.0 is a good choice for you.