Using Exteral Microphones and Calibration

bikeamtn

Would I be correct in saying?
SoundMeter (and other FaberAcoustical app's) should be able to use an ext. mic such as the MicW i436 Calibrated Measurement Type 2 External Mini Microphone for iPad, iPhone, and iPod Touch. Also; since such mic's come with caliberation data, you can simply manually enter this data into the application and all should now be calibrated.

Would this assumption be correct? Thanks

benfaber

bikeamtn,

Yes, you can use the i436. However, the i436 is still subject to the high pass filter that Apple applies to the headset mic input of iOS devices (even Macs with headset support apply a filter). Frequency response plots of the filter can be found on our blog.

You can just enter the sensitivity of the mic in mV/Pa to get accurate readings (except at frequencies affected by the filter), although a proper calibration is still generally recommended.

Ben

bikeamtn

Forgot about the high-pass filter (applied to headset). Internal mic is the way to go for now.

Thanks

benfaber

Please keep in mind that the same high pass filter is applied to the built-in mic. We need enough people to tell Apple of their desire to bypass the filtering. Perhaps, someday Apple will enable us to bypass those filters.

Ben

Jasonaudio

Good day,

Is this still an issue? I just order a i436 on amazon and waiting to ship it. And I'm using a iPad mini do I still need to calibrate it? Thanks.

benfaber

Jasonaudio,

The high-pass filter is bypassed in our measurement apps as of iOS 6. You can learn more about this on the blog.

Microphone sensitivity calibration is always recommended. However, if you don't have a microphone calibrator handy, it may be more convenient to perform a voltage calibration and then manually enter the acoustic sensitivity (mV/Pa) that was provided with the i436.

Ben

Jasonaudio

Hi Ben thanks for the reply, do you have a guide how to perform a voltage calibration?

Cheers,

RedWood

Jasonaudio wrote Hi Ben thanks for the reply, do you have a guide on how to use PhenQ to get the most out of it?

Cheers,

That would be very helpful. I can't seem to find any step by step voltage calibration guides online.

benfaber

SoundMeter's built-in documentation includes a device input voltage calibration tutorial.

To access the documentation, tap the info button ("i") in the toolbar at the top of the main screen. Then, tap on Help in the Info screen.