A Decibel Meter as a Free Speed Meter?

[p1n9183]

20 hours ago, iacas said:

So bad, I'm not going to spend the ten minutes it would take to do such a thing, because I know what the results would be.

An you still took several minutes to write several posts and talk to sound engineers. I appreciate that you did!

21 hours ago, iacas said:

• temperature
• distance of max clubhead speed from the microphone
• angle (both axes) to the microphone
• clubface orientation (a face open or closed will change the frequency)
• location of the max clubhead speed (reaching peak speed at the same exact place)
• everything in the vicinity, including the shoes and clothes you're wearing, the surface you're on, etc. ideally with all of them producing virtually no noise even when moving.

 So they basically tell you is possible but you need to be very restrictive. The same thing I found on my research. 

Temperature: is not going to change much between swing A and swing B.
Distance of max club head: even the PRGR take the fastest speed recorded, not the speed at the ball. But this could be diminish by swinging several times each swing and average the results. 
Angles: also PRGR returns less speed swinging on a certain degree. 
Clubface orientation: it is also an issue with launch monitors that are not reading the center of the mass of the club. You can have a lot more club speed if your face rotation is higher and your lunch monitor is reading the toe of the club.
"Other stuff in the room": are the same from swing A to B, or you can just swing naked! haha 

21 hours ago, GolfLug said:

He said he installed a free decibel app on his phone. He himself has a PRGR apparently but if the idea had merit, others could benefit.

This is the main idea, I have a PRGR and Skytrak. There are plenty of people, more here in Argentina, that can't afford a launch monitor. Also wanted to share the idea and let it be challenged by others. I don't mind been wrong, is part of experimenting. 

20 hours ago, GolfLug said:

I would have thought that would be the first thing to do if to see if this had merit. Maybe he has.. @p1n9183?

I did and all the swings were close to 85 dbs, me swinging at 90 m/h. But I don't mind doing a proper test later in the afternoon writing down the results. I need to find and app that also have frequencies in order to test both. 

 

[billchao]

12 minutes ago, p1n9183 said:

Temperature: is not going to change much between swing A and swing B.

But it will change from session to session, from one person’s location to the next, etc. If your goal is to figure out X db = Y mph in swing speed to share with others, that matters.

[iacas]

43 minutes ago, p1n9183 said:

An you still took several minutes to write several posts and talk to sound engineers. I appreciate that you did!

You could have saved us all some time by realizing I tend to know what I'm talking about when it comes to science and tech. 😛 

43 minutes ago, p1n9183 said:

So they basically tell you is possible but you need to be very restrictive. The same thing I found on my research.

What?

The only way they would imply that it would be "possible" is if you were able to spend six figures (minimum) AND that doesn't include the swing robot that could reach peak speed at the same exact location every time.

No, they didn't say it was possible for someone like you to do anything remotely good.

43 minutes ago, p1n9183 said:

Temperature: is not going to change much between swing A and swing B.

Session to session.

43 minutes ago, p1n9183 said:

Distance of max club head: even the PRGR take the fastest speed recorded, not the speed at the ball. But this could be diminish by swinging several times each swing and average the results.

The PRGR doesn't work the same way - it samples the speed, from behind (inline with the direction of travel) with radar, and takes the highest number it registers. The distance from the PRGR isn't super relevant.

43 minutes ago, p1n9183 said:

Angles: also PRGR returns less speed swinging on a certain degree.

Clubface orientation: it is also an issue with launch monitors that are not reading the center of the mass of the club.

You're not reading. Or understanding. No to both.

The former is because of the microphones, and the latter is because a clubhead swing more closed versus more open will have a different air flow and thus a different pitch and volume. Clubheads are not symmetrical.

43 minutes ago, p1n9183 said:

"Other stuff in the room": are the same from swing A to B, or you can just swing naked! haha 

You're missing the point. How reflective some of that stuff is could matter. The sounds it generates to background noise could matter.

43 minutes ago, p1n9183 said:

I did and all the swings were close to 85 dbs, me swinging at 90 m/h. But I don't mind doing a proper test later in the afternoon writing down the results. I need to find and app that also have frequencies in order to test both.

85 dBs is generally considered ear-injuring volume.

You don't "need to find an app" because this will not work at all.

[GolfLug]

Decibels is sound 'pressure' not wave frequency. From that perspective a SGI Iron will have very different pressure wave than a blade even with the same speed and other variables considered equal. Additionally, since your phone will not be in direct path the turbulence difference (which generates the sound 'pressure) will have much lesser variance. In other words you will have convergence at one particular speed. Maybe it's this 90MPH speed with your 6i. But I doubt you will have proportional deviation above or below the speed to give you anything will reliability. 

2 hours ago, p1n9183 said:

I did and all the swings were close to 85 dbs, me swinging at 90 m/h. But I don't mind doing a proper test later in the afternoon writing down the results. I need to find and app that also have frequencies in order to test both. 

And other speeds? 80, 90? 

[p1n9183]

Here are the numbers of the test I just finished.
Firstly I tested the app Spectroid were you can messure Hz and Db. Must admit that frecuencies were all over the place and only after 5 swings I switched to another app. Decibels were not normally messured so it was useless info. 

Then I downloaded a basic decibel meter to repet the test I did earlier in the week. It was the "Sound Analyzer app" and I made 20 swings with my 6 iron. I put a coin in the corner of a tile on the floor, the PRGR 5 feet behind away from the path of the swing and half foot away from the coin (away from me) I set the phone with the decibel metter app and I swan away from the PRGR and parallel to the phone. This are both readings. 

I ordered the speed from "slow" to "fast" and inserted a graph to see if there is any correlation between the speed and the decibels. 

As spected on lower swing speeds the ambience sound was even louder than the swoosh of the club so the method was usless. But at higher speeds, beginning at around 60 m/h, it was easy to see that there was a relationship between both. They weren't growing at the same pace but it was proportional.

At least for me, for a free app in an old smartphone it seams pretty usefull to know if swing A is faster than swing B in a particular practice session. When you want more speed, all you want to know is if your new move or swing though or technical change is going to give you more or less speed, looking at the decibels is really easy to see that and you don't need to spend money on launch monitors. 
Of course, if you want someting that can compare your speed from place to place, session to session or club to club then you don't have much choice than go and get the launch monitor you can afford. 

Bonus: Linear regresion of both variables.  Y: db, X: m/h

Edited 3 hours ago by p1n9183