Measuring frequency response on iphone 3G?

[Bloodstriker]

Measuring frequency response using iphone 3G?

I was wondering if anybody had any experience with Faber Acoustical's iphone SignalScope application? I saw this on the App Store last night.

Here's the description:

SignalScope turns your iPhone into a powerful real-time spectrum analyzer and oscilloscope. Easily measure audible frequencies in SignalScope’s Spectrum tab. Capture a balloon pop with single-shot triggering in the Waveform tab. “Touch” your data with highly interactive, multi-touch enabled analyzer displays.

FEATURES
Analyze signals coming from the iPhone's built-in or headset microphone, or from the built-in accelerometer.
Zoom in or out on spectrum and waveform displays with two-finger expand/pinch gestures, even while the analyzer is running.
Pan vertically or horizontally in zoomed displays with two-finger scrolling.
Pinpoint individual sample values or frequencies with a cursor.
Save high-resolution spectrum or waveform display images to the iPhone's Camera Roll photo album.

http://www.faberacoustical.com/products/iphone/signalscope/

At $25.00, it's a bit expensive to purchase without having some more info! If it works, could I calibrate my system/room based on this?

 

[10010011]

Chances are the iPhone's built in microphone does not have a very flat frequency response.

Without any sort of correction factors measurements would be dubious at best.

 

[Bloodstriker]

Hmm..

http://www.faberacoustical.com/forum/index.php/topic,54.0.html

No idea what his measurements mean. Any clues?

 

[jamie2112]

Hmm..

http://www.faberacoustical.com/forum/index.php/topic,54.0.html

No idea what his measurements mean. Any clues?

Anything making Square waves is not good Period.

 

[no. 5]

Chances are the iPhone's built in microphone does not have a very flat frequency response.

Without any sort of correction factors measurements would be dubious at best.

Definitely agreed, but it still may be fun to have.

But there is the possibility that the writers of the app made correction factors for the iPhone's microphone.

 

[Bloodstriker]

I just bit the bullet and I'll let you guys know how it is.

Where do you see square waves?

 

[Bloodstriker]

Update:

I had a chance to spend a bit of time with this app. I have to say, I don't really know what I'm doing. However, it seems like the dB limit is a bit on the low side?
I'll post some pics to see if you guys can make heads or tails of this.

 

[xuancongwen]

The square wave comment doesn't really make any sense. The figure he referred to was the last one where they used the signal generator functionality to generate a square wave. I think he mistakenly believed that natural sinusoids were being distorted into square waves, which is of course awful, but the iPhone most certainly doesn't do that.