DA 60 Sound Levels

[Lardog]

Hey all... Hoping someone can help me out with some info. I currently have a DA 60 with ProFlow can. Runs great and is nice and quiet. I'm looking to put this engine in a new airframe but would like to go without the extra weight of the canister. My field has a 90dB limit. I'm wondering if anyone has real sound measurements of the DA 60 spinning a Falcon 24x9 with a JTEC pitts muffler. Ideally, I'd like info on both the standard and the extra large version. If you have rpm #s, that'd be great too?

Will my engine pass the sound check with the pitts?

Thanks,
-Larry

 

[Kevin-Young]

Larry,

What is the distance that they are measuring your sound at?  90db is awefully low at the standard AMA measurements and most of your canisters would not meet that so if you can provide the distance you measure at and also what you measure with the proflow can we may be able to give you an idea of what to expect with one of our mufflers.  I will tell you the large version of the 60 wrap around should give you about the same db level as the proflow can and with any of our DA mufflers you should get the same rpm as everything we do is tested on DA stuff.

Kevin

 

[Lardog]

Thanks Kevin. It's 90dBA measured at 25 feet on grass. I don't know what the measurement is with the ProFlow. All I know is that it is quiet enough.

 

[Kevin-Young]

That basically works out to be the same formula the AMA uses just at a different distance.   AMA uses the standard of 96db over grass at 10ft (3m).  At your distance that works out to be about the same formula, here is a link to a calculator I found for figuring out the formula.  http://www.sengpielaudio.com/calculator-distance.htm 

So for example our large wrap around on the DA 60 is about 95db at 3m, so at your distance you would be at 88db.  At your distance our standard wrap around should be in the 90-91db range.

Now there are other factors that will factor into this such as prop, vibration, and carb.

 

[Lardog]

Great info. Thanks Kevin.

 

[stangflyer]

It would be interesting to hear what your db numbers are. I couldn't even get my DLE 55 to pass on a tuned header and can. Swinging a Falcon 23x8 CF. Keep us posted??