$5.99 from Studio Six Digital
SPL is a professional-grade digital sound level meter (decibel meter) for your iPhone. It includes all of the modes, filters, and features that you would expect from an ANSI or IEC Sound Level Meter. All filters and averaging modes meet or exceed the criteria for ANSI Type 1 or better. SPL is created from the same folks who brought you the Audio Toolbox and ATB Plus.
** ON SALE — Buy now, the price will be going up soon to $7.99.
Graphics — This version has three user-selectable options for the front panel. These include aluminum, dark metal, and plain. The dark metal option, with blue digits, is designed to work best in dark environments. Use aluminum or plain in daylight.
Store Results — We now have provided 9 memory slots for storing results. The dB SPL level, mode, weighting, time, date, and a description are all stored. Also, for non-Leq modes, the max and relative are stored, and for Leq, the Max and Leq time.
The iPhone 3G has the best microphone frequency response. SPL will work on the first generation iPhone, but without the same accuracy. You can also use SPL with our calibrated iPhone measurement mic, see below for details.
If you have an iPod Touch 2nd Generation, SPL will work, but you need to use an external mic, like the headphones / mic that is included with the iPhone.
The screen flips if you turn the phone upside down, so that you can point the built-in mic directly at the sound source.
Modes: Slow, Fast, Impulse, Peak, and Leq.
Filters: A and C weighting, and 10 octave band filters.
Includes a resettable Max field to track the highest reading.
Includes a reference field (except in Leq mode) so that you can set a reference level and do seat-to-seat comparisons.
The SPL meter can be fully calibrated. It comes preset with the calibration for a typical iPhone 3G. Most iPhone model 3G will be within a few dB of this reading. If you have access, even temporarily, to a calibrated sound level meter, just use the calibration field on the flipside to match the meter, and you will be accurately calibrated.
Also, see our other professional-grade audio apps: Speaker Pop, to test speaker polarity, and RTA, a real-time analyzer for the iPhone.
And, we will soon be releasing a calibrated, accurate measurement microphone for the iPhone. This will allow measuring a range from approximately 40 dB SPL to 105 dB SPL. Each mic will include a calibration factor that you will enter into the SPL app for calibrated measurements. This mic will also work with Speaker Pop, our speaker polarity tester, RTA, ETC, and other acoustical measurement apps that we will be releasing soon.
NOTE: I have enabled the “buy for first gen Touch option”, but be advised that you have to arrange your own input via the dock connector. This model does not support the headset mic nor does it have an internal mic.
Coming soon, an iPhone internal mic compensation filter, to cancel out the low-frequency roll-off present in the iPhone.
See our other audio apps: RTA, the 1/3 octave Real TIme Analyzer, LEQ, for recording SPL over time, Speaker Pop, the speaker polarity tester for the iPhone, ETC, an Energy Time Curve and room decay analyzer for iPhone, FFT, for advanced acoustic analysis, and Generator, the full-featured signal generator for iPhone.
Also, if you are looking for a great range of high-quality, professional, audio test equipment, check out http://www.sencore.com. They sell the current versions of the Audio Toolbox, as the SoundPro line of audio test equipment.