SoundMeter and dB support new iPads

Nominal microphone sensitivities for the iPad Air and iPad mini with Retina display have been added to SoundMeter 4.0.1 and dB 3.0.1.

Both apps also display dark blue toolbars in the black color scheme to make it easier to view the screen in dark environments.

SoundMeter additionally corrects the HTTP file server configuration screen, which now scrolls to reveal the web URL on 3.5-inch iPhone screens (the file server is available for in-app purchase as part of the data acquisition upgrade).

SoundMeter Screenshot iPhone 5

 

SoundMeter 4.0.1 and dB 3.0.1 are both available for download on the App Store.

Download SoundMeter

Download dB

 

Faber Mac Apps Updated for Mavericks

All Faber apps for Mac have been updated for Mac OS 10.9, Mavericks. These are minor updates, which include the following improvements:

– This update addresses plot freezing issues on Mac OS 10.9 (Mavericks).

– SLM and Octave Analyzer tools operate more efficiently.

– A potential crash has been addressed in the Signal Generator tool.

Electroacoustics Toolbox 3 Screenshot Electroacoustics Toolbox Screenshot 2

 

Download a free trial from FaberAcoustical.com:

Download Electroacoustics Toolbox 3.4.1

Download SignalScope Pro 3.1.5

Download SignalScope 3.1.5

Download SignalSuite 4.1.5

 

Download from the Mac App Store:

Download Electroacoustics Toolbox 3.4.1

Download SignalScope Pro 3.1.5

Download SignalScope 3.1.5

Download SignalSuite 4.1.5

 

SignalScope Pro 3.0 for iOS 7

In the new version 3, SignalScope Pro’s appearance has been completely revamped for iOS 7. SignalScope Pro supports both iOS 6 and iOS 7, but looks largely the same on iOS 6 as the previous version.

Also new in version 3:

– Audio data handling is more efficient.

– Image overlays created in the Level Meter tool now use the full resolution of the original image (whether the image comes from the photo library or straight from the camera).

– For devices that support input gain adjustment on the built-in or headset microphone, the input gain is stored with data exported from the FFT, Octave, or Oscope tools.

– When entering a preferred sample rate, “48k” can be entered in the text box, as an alternative to typing out “48000.”

– Default input sensitivities have been updated, based on measurements of the iPhone 5S and 5C microphones and headset inputs.

– Cursor info text now uses a larger font.

 

SignalScope Pro Screenshot iPhone 1 SignalScope Pro Screenshot iPhone 4 SignalScope Pro Screenshot iPhone 5

SignalScope Pro Screenshot iPhone 2 SignalScope Pro Screenshot iPhone 3

 

Download SignalScope Pro

SignalScope, SoundMeter, and dB have also received similar updates for iOS 7.

Download SignalScope

Download SoundMeter

Download dB

Octave Analyzer tool for iOS

 

The Octave Analyzer tool for iOS performs real-time spectral analysis in whole or 1/3-octave frequency bands.

The Octave Analyzer tool is built into SignalScope Pro. It is also available in SignalScope and SoundMeter via in app purchase.

The Octave Analyzer can analyze up to two audio input channels simultaneously (this requires a two-channel input device).

The Octave Analyzer can be configured with several options that are common to overall sound level meters. These options include time weighted exponential average levels with fast, slow, and impulse response times as well as the equivalent level, which expresses an average signal level over the total measurement time. Flat, A, and C frequency weighting are also available.

The Octave frequency spectrum appears within a bar graph which can be adjusted in its vertical scale either manually or automatically. In addition to current levels within each frequency band, maximum or peak levels may also be displayed, depending on which level type is selected. A data cursor allows specific levels at specific frequencies to be identified. The entire graph can be saved either as an image in the iOS photo library, or as a high resolution PDF file within the app.

Additionally, in SignalScope Pro, Octave analyzer data may be exported to CSV, MAT, or tab-delimited text files. Data export is also possible in SignalScope and SoundMeter with the optional Data Acquisition Upgrade available via In-app Purchase.

Download:

SignalScope Pro

SignalScope

SoundMeter

SoundMeter 3.3 can turn your iPhone or iPad into a personal noise dosimeter

SoundMeter 3.3 offers users the option to add a noise dosimeter tool via in-app purchase. The new Dosimeter tool enables you to measure noise dose–the percentage of a maximum permissible daily noise exposure based on an 8-hour time period. The Dosimeter supports criterion levels of 80, 85 and 90 dB, exchange rates of 3, 4 and 5 dB, and thresholds of 40 to 80 dB. The new tool also displays the 8-hour time-weighted average sound level (TWA), as specified by OSHA.

As with other measurements in SoundMeter, the Dosimeter’s accuracy depends on the quality of the microphone used as well as the accuracy of the microphone’s sensitivity calibration within SoundMeter.

SoundMeter 3.3 also includes updated Help files, minor bug fixes, and stability improvements. SoundMeter 3.3 will also continue to run while the screen is locked, which is important for making long-duration measurements, such as noise dose, Leq, and TWA.

  SoundMeter Noise Dosimeter

 

Download SoundMeter 3.3 on the App Store.

 

Are you looking for a measurement microphone for your iPhone?

Since iOS 6 finally remedied the low frequency roll-off problem of the headset mic input of the iPhone, iPod touch, and iPad, the headset jack has become a suitable option for measurement microphone input. Prior to the release of iOS 6, the only way to connect an external measurement microphone, without sacrificing low-frequency information, was to go through the dock connector. Dock connector devices can still provide higher quality solutions, but working with the headset jack offers a level of portability (i.e. compact size) that cannot be matched when a 30-pin dock connector is involved (we’ll see what comes along to take advantage of the new Lightning connector).

MicW i436

Some time ago, I was made aware of the i436 measurement microphone from MicW. It looked like exactly what was needed to turn any iOS device into a quality sound level meter, or acoustical analysis tool, that you could truly carry around in your pocket. However, it was limited in its utility by that pesky low-end roll-off that plagued earlier versions of iOS. Some developers attempted to perform software correction for the input filters, but when an input signal is driven into the noise floor by the hardware (or firmware), there’s nothing app software can do to restore the lost signal at those lower frequencies. Now that iOS 6 has solved the issue, the i436 has become the attractive measurement microphone solution for iOS that it should have been when it was first introduced.

i436i436

Last weekend, I carried the i436 around the Denver Tech Center Marriott at the Rocky Mountain Audio Fest (RMAF), along with my iPhone 5. The i436 is small enough that it could slip into my pocket and remain there unnoticed or it could stay connected to the iPhone, which was perched in my shirt pocket when it wasn’t in my hand. In short, I was quite pleased to confirm that the i436 does indeed make for a portable measurement solution that you can carry in your pocket all day long.

MicW i436 Noise Measurement

As for quality, the i436 looks and feels like a proper measurement microphone. It was designed to meet the Class 2 standard for sound level meters, which addresses issues like environmental stability in addition to frequency response. The i436 also fits a standard microphone field calibrator, with a 1/4″ adapter, which you would also expect from a measurement microphone. A field calibrator makes microphone sensitivity calibration very easy with measurement software like SoundMeter or SignalScope Pro.

i436 Typical Frequency Responsei436 Typical Polar Pattern

The i436 is available in a package with just the mic, or in a kit. The kit includes a wind screen, extension cable, splitter cable (to connect headphones or an audio cable to the headphone output), a small clip, and an aluminum storage tube that doubles as a holder for the i436 that mounts to the top of a standard microphone stand (very handy).

i436 Single Packagei436 Kit Package

If Class 2 compliance meets your needs, then I highly recommend the MicW i436, especially in the kit. Either option is quite affordable for a quality measurement microphone. If you need a microphone that conforms to the Class 1 standard, then another hardware solution will be necessary.

Stereo 1/3-octave analysis now available in SignalScope Pro

With the release of version 2.2, the Octave tool in SignalScope Pro for iOS can now analyze two input channels simultaneously. This new capability is only available on devices running iOS 5 or later, and it requires a stereo or two-channel dock connector audio accessory.

     

The Octave tool offers whole and 1/3-octave real-time spectral analysis with A, C, or flat frequency weighting and fast, slow, or impulse time weighting. Time exponential averaged level (Lp) and equivalent level (Leq) measurements are both supported.

The Octave tool available via in-app purchase in SoundMeter 3.0 and SignalScope 3.2 also offers two-channel measurement capability on iOS 5 or later. SoundMeter 3.0, SignalScope 3.2 and SignalScope Pro 2.2 are all available for immediate download on the App Store.

Improvements in SignalScope 3.2 and SignalScope Pro 2.2 include:

  • For users running iOS 5, or later, the Octave analyzer tool can now be operated as a stereo RTA, analyzing two input channels simultaneously (with compatible input hardware). (The Octave tool is available within SignalScope via in-app purchase.)
  • Data can now be exported to CSV files from the FFT, Octave, and Oscope tools. CSV files can be opened directly in Numbers, or other spreadsheet apps that support it, from within SignalScope. Tab-delimited text files can still be created by giving the file name a .txt extension. (Data file export requires the data acquisition upgrade available within SignalScope via in-app purchase.)
  • Corrects a potential crash when accessing the image picker on iPad.
  • SignalScope uses less memory on iPhone and iPod touch.
  • Twitter support has been restored (in iOS 5) for tweeting level meter data. (The Level Meter tool is available within SignalScope via in-app purchase.)

SoundMeter 3.0 offers in-app upgrades

  SoundMeter 3.0 is now available for download on the App Store,

offering in-app purchases of the same tools found in SignalScope Pro. Available upgrades include dual-channel Octave RTA, Oscilloscope, and FFT Analyzer tools, as well as a data acquisition upgrade.

Dual-channel analysis in the Octave tool enables SoundMeter to be used as a stereo 1/3-octave RTA. This dual-channel capability requires iOS 5, and is also coming soon to the Octave tool in SignalScope and SignalScope Pro, but it is available now in SoundMeter. (In SignalScope, the Octave tool is also available via in-app purchase.)

SoundMeter’s new data acquisition upgrade enables the user to export Octave, Oscope, and FFT data to CSV, tab-delimited text, and MAT files, and to access those files from a web browser on another device. This upgrade also enables additional units, such as V, A, g, and ips to be assigned to input signals.

Download SoundMeter 2

SoundMeter 2.0 is on the App Store

As in recent updates to SignalScope and SignalScope Pro, SoundMeter now runs natively on iPad, as well as iPhone and iPod touch.

SoundMeter now supports drawing on an external screen with a compatible video output adapter. The original iPad supports external screen resolutions up to 720p and the iPad 2 supports resolutions as high as 1080p and even 1920×1200 with compatible hardware. Video output support is not supported on iPhone or iPod touch.

SoundMeter also supports saving the sound level display to PDF files, which can be accessed via iTunes File Sharing on a Mac or PC. The same black, blue, and white color schemes as found in SignalScope Pro 2 are also supported in SoundMeter 2.

Download SoundMeter 2

SoundMeter 2.0 Screenshot

iPhone Microphone Frequency Response Comparison

With the advent of sound level meter apps for the iPhone OS (of which SoundMeter was the first) people began to ask, “How flat is the frequency response of the iPhone’s microphone?” Early testing indicated that the built-in microphone of the original iPhone was not a good candidate for sound level measurements, but that the iPhone’s headset microphone enjoyed a fairly flat response. Since then, additional iPhone models have arrived on the scene, each with its own set of weaknesses with respect to microphone frequency response. Additional Apple and third party headset microphones have also been introduced.

At long last, some relevant frequency response measurements are presented here for the benefit of those who would really like to “see” how flat a particular microphone is. These results have implications on the use of certain microphones for making sound level measurements, as well as on the use of these microphones for spectral analysis in which relative amplitudes need to be determined with some degree of accuracy.

The following measurements were made relative to a Type 1 precision microphone in a fairly quiet room. These measurements were not made in an anechoic chamber and although the coherence was very good across the audio band, the measurement error is non-negligible at high frequencies, because of diffraction effects.

Built-in Microphones

Built-in iPhone Microphone Frequency Response

Built-in iPhone Microphone Frequency Response Comparison

As I have often said, “The built-in microphone of the original iPhone is not recommended for sound level measurements.” Now, you can really see what I mean. Interestingly, the built-in microphone of the iPhone 3GS isn’t recommended, either, unless you don’t care about frequency content below 200 Hz. This behavior is consistent with the headset input frequency response of the iPhone 3GS (I suspect that the built-in microphone signal goes through the same high-pass filter that gets applied to the headset input). The iPhone 3G microphone’s response is clearly the best of the bunch, but its low end rolls off by 15 dB or more at 20 Hz. Not surprisingly, none of the iPhone models rivals a lab-grade sound level meter with its built-in microphone, but either of the 3G models can potentially give you a decent ball-park estimate of the current sound level, although the low frequencies will be de-emphasized.

Headset Microphones

The goal, here was not to measure every headset microphone on the market, but to take a look at some of the more common options. These measurements were made of each microphone’s electrical output, so they do not include the response of any iPhone input or output circuitry. The microphones included in these measurements are:

iPhone Headset Microphone Frequency Response Comparison

iPhone Headset Microphone Frequency Response Comparison

In the world of headset microphones (at least those that are presented, here), the official iPhone headset microphone and the SwitchEasy ThumbTacks microphone win the day. The USBFever microphone also exhibits a flat response between 20 Hz and 2 kHz, although its response appears to break up more severely by the time it gets up to 10 kHz. In light of recent headset input frequency response measurements, the best case scenario for inexpensive sound level measurement might be to use the ThumbTacks microphone with the original iPhone.

These results are also interesting, in that they strongly suggest that the newer Apple headsets, which are designed primarily for iPods, shouldn’t be used for sound level measurements, either. Their response certainly seems to follow an apparent trend with Apple’s microphone-related circuitry to de-emphasize low frequencies.

It may be important to keep in mind that the goal, here, is to see what makes sense in terms of using iPhone OS devices as inexpensive, portable sound level and spectrum analysis tools. Obviously, there was never an expectation that the iPhone’s inexpensive microphones would perform in a manner consistent with precision measurement mics that are (justafiably) much more expensive. It is possible to connect such high-end microphones to an iPhone, though (via the dock connector)–more on that, later…

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