Faber Acoustical Forum

Faber Acoustical iOS Apps => SoundMeter => Topic started by: bikeamtn on January 02, 2012, 09:36:53 PM

Title: Using Exteral Microphones and Calibration
Post by: bikeamtn on January 02, 2012, 09:36:53 PM
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
 
Title: Re: Using Exteral Microphones and Calibration
Post by: FaberAST on January 03, 2012, 10:40:26 AM
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
Title: Re: Using Exteral Microphones and Calibration
Post by: bikeamtn on January 06, 2012, 09:22:22 PM
Forgot about the high-pass filter (applied to headset). Internal mic is the way to go for now.

Thanks
Title: Re: Using Exteral Microphones and Calibration
Post by: FaberAST on January 10, 2012, 06:27:35 AM
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
Title: Re: Using Exteral Microphones and Calibration
Post by: Jasonaudio on April 12, 2013, 09:44:43 PM
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.

Title: Re: Using Exteral Microphones and Calibration
Post by: FaberAST on April 15, 2013, 09:20:38 AM
Jasonaudio,

The high-pass filter is bypassed in our measurement apps as of iOS 6. You can learn more about this on the blog (http://blog.faberacoustical.com/2012/ios/iphone/finally-ios-6-kills-the-filter-on-headset-and-mic-inputs/).

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
Title: Re: Using Exteral Microphones and Calibration
Post by: Jasonaudio on April 19, 2013, 09:35:32 PM
Hi Ben thanks for the reply, do you have a guide how to perform a voltage calibration?

Cheers,
Title: Re: Using Exteral Microphones and Calibration
Post by: RedWood on January 25, 2016, 04:13:02 AM
Hi Ben thanks for the reply, The https://peblueprint.com/bathmate-review new bathmate is great. Do you have a guide how to perform a voltage calibration?

Cheers,

That would be very helpful. I can't seem to find any step by step voltage calibration guides online.
Title: Re: Using Exteral Microphones and Calibration
Post by: FaberAST on January 25, 2016, 10:27:37 AM
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.