Faber Acoustical Forum

Faber Acoustical iOS Apps => SoundMeter => Topic started by: FaberAST on August 11, 2008, 09:22:20 PM

Title: Welcome to the SoundMeter forum!
Post by: FaberAST on August 11, 2008, 09:22:20 PM
A sound level meter app for iPhone has been a hugely popular request. Now that SoundMeter is available (http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=287615105&mt=8), you can voice your questions, concerns, praises, and suggestions in this forum.
Title: Thanks with a question
Post by: dsd on August 13, 2008, 05:57:30 AM
Wow, I suggested something and you made it!  Very Cool :-)

I have a gen1 iphone and I guess I should use an external microphone?  What did you use or recommend (part number)?

Thanks and I will buy it as soon as I know whether to buy a mic or get a 3G.

-dsd
Title: Re: Welcome to the SoundMeter forum!
Post by: FaberAST on August 13, 2008, 09:33:10 AM
dsd,

With a 1st generation iPhone, your best bet, for now, is to use the headset mic that came with it. When you plug that in, SoundMeter will use a default sensitivity that should get you pretty close to the mic's actual sensitivity.

Another option would be to make your own little mic, using an electret condenser microphone (ECM) capsule. Since the iPhone's headset connector provides a bias voltage, you shouldn't need to do much more than wire up the capsule to the headset mic input.  You'll need to calibrate it, though.

Ben
Title: Re: Welcome to the SoundMeter forum!
Post by: chad on August 14, 2008, 02:43:15 PM
I read the FAQ, but don't have another meter to calibrate with. Do you have any suggestions on calibrating the mic?
Any known signals and their corresponding level?

halp pls
kthxbye
Title: Re: Welcome to the SoundMeter forum!
Post by: FaberAST on August 14, 2008, 04:28:35 PM
chad,

If you don't have access to a calibrated meter with which to calibrate SoundMeter, your best bet may be to just use the default sensitivity. If you want to use a third-party headset mic, you'll want to be sure it has a reasonably flat frequency response and find some way to calibrate it.

Ben
Title: Re: Welcome to the SoundMeter forum!
Post by: wineinger on August 14, 2008, 06:11:47 PM
What is the default setting?  I hit calibrate thinking an auto calibrate was about to happen.  Now I have the sensitivity that is coupled with that calibration. 
Title: Re: Welcome to the SoundMeter forum!
Post by: FaberAST on August 15, 2008, 11:17:54 AM
The default sensitivity values for SoundMeter are:
Built-in Mic:        3.85 Pa/FS
Headset Mic:       2.05 Pa/FS

You can also uninstall and reinstall the app to reset to default values.
Title: Re: Welcome to the SoundMeter forum!
Post by: supergimp on August 15, 2008, 03:27:39 PM
Awesome app. I work in film sound and don't need ultimate accuracy but need to check balance a lot. This looks useful.

However, I can't seem to change the weighting. It stays on Flat and I can't set A or C weighting. Is this feature supposed to work or am I missing something?

Thanks,

Steve

Title: Re: Welcome to the SoundMeter forum!
Post by: FaberAST on August 15, 2008, 03:35:39 PM
Steve,

Frequency weighting is disabled when using the built-in microphone on the original iPhone. In general, it is recommended to use the iPhone's included headset mic, when working with first generation iPhones. The built-in microphone of the iPhone 3G works quite well, however.

Ben
Title: Re: Welcome to the SoundMeter forum!
Post by: bigbillpns on August 15, 2008, 08:57:44 PM
I downloaded this morning to my iPhone 3G and the operation seems fine, although a comparison with another SLM showed a difference of about 10 db.  The other unit has not been calibrated for a long time, so I am waiting to do other comparisons before I make a judgement.

I am most interested in having some kind of logging capability, ideally a graph showing fast or slow (average) response or even another line showing peaks. If it could be done at the reading rate that the display (which seems to be a sample per second or better) that would be great in a trouble shooting enviroment.   And the time display (including seconds) should also be included in the image storage.

What are the development plans for this app, what programing might be done by users??

The ablility to correlate these reading with a video or other time notation seems possible, if so, this could be a very valuable tool.

Bill in Pensacola  UWF Physics Lab Manager
Title: Re: Welcome to the SoundMeter forum!
Post by: FaberAST on August 18, 2008, 03:19:56 PM
Thanks for the feedback, Bill.

Quote
what programing might be done by users?
Programming by users?  What do have in mind?

Ben