Help With Frequency Response Curve

[irishpatrick33]

Hello,

I am wondering if someone can provide advice. So I built some test speakers and ran a linear sine wave frequency sweep through them. Using my iPhone 6, I recorded the output from 1" away. So now I am trying to put together the data. My understanding is that I have to somehow compensate for microphone frequency response?

Ultimately, I am trying to plot a frequency response curve graph. I'm using free software, Audacity. I am not sure what options I am supposed to choose for: algorithm, function, size, and axis. Again, not sure how I compensate for mic either.

Any help is appreciated. Thanks!

 

[arnyk]

Hello,

I am wondering if someone can provide advice. So I built some test speakers and ran a linear sine wave frequency sweep through them. Using my iPhone 6, I recorded the output from 1" away. So now I am trying to put together the data. My understanding is that I have to somehow compensate for microphone frequency response?

Ultimately, I am trying to plot a frequency response curve graph. I'm using free software, Audacity. I am not sure what options I am supposed to choose for: algorithm, function, size, and axis. Again, not sure how I compensate for mic either.

Any help is appreciated. Thanks!

There is good freeware for doing acoustical tests - Holme Impulse and Room Eq Wizard come quickly to mind. They are based on swept sines, but they also handle the analysis.

 

[CharlieLaub]

My understanding is that I have to somehow compensate for microphone frequency response?

H-E double hockey sticks, yeah you do.

Don't use the iPhone's built-in microphone if you want to make any serious measurements. There are some plug-in mics that you can purchase for the phone that are a big improvement. Example:
http://www.amazon.com/Dayton-Audio-iMM-6-Calibrated-Measurement/dp/B00ADR2B84
Even with this, your measurements will not be perfect, but will be more accurate than the phone mic for sure.

The best option is to use a calibrated mic ($50) but you will also need a mic preamp for it and an actual computer for data acquisition. Audacity has nothing to do with frequency measurements. You need a measurement program like ARTA.