SignalScope and IOScope support sample rates up to 192 kHz

Current versions of SignalScope (3.6.2), SignalScope Pro (2.6.2), and IOScope (2.5) include advanced audio configuration options that support user selection of the audio sample rate. Using built-in iPhone and iPad audio hardware, this typically means that sample rates as low as 8 kHz can be selected. Since the iPad additionally supports external USB audio devices, via the iPad Camera Connection Kit or the Lightning to USB adapter, sample rates as high as 192 kHz can be made available with the right hardware. Which sample rates can be selected depends on values supported by the connected audio hardware.

Typical sample rates for the built-in microphone or headset input of current iOS devices include:

  • 8 kHz
  • 11025 Hz
  • 12 kHz
  • 16 kHz
  • 22.05 kHz
  • 24 kHz
  • 32 kHz
  • 44.1 kHz
  • 48 kHz

It is possible to sample audio data at up to 192 kHz, with USB devices that support it, on iPad. One such device is the Echo 2 from Echo Digital Audio, which supports sample rates of:

  • 44.1 kHz
  • 48 kHz
  • 88.2 kHz
  • 96 kHz
  • 176.4 kHz
  • 192 kHz

SignalScope, SignalScope Pro, and IOScope are all available for download on the App Store.

Download SignalScope

Download SignalScope Pro

Download IOScope

The Echo 2 is available from B&H Photo Video and from Amazon.

SignalScope Pro 192 kHz Sampling

Input triggering now available in the FFT analyzer on iOS

SignalScope 3.5 and SignalScope Pro 2.5 for iOS have arrived on the App Store with added support for input triggering in the FFT spectrum analyzer tool. Triggering support essentially matches that in the Oscope tool, including Auto, Normal, and Single-shot triggering modes, positive or negative slope triggering, and a user-definable input level threshold.

Also new in these apps is a 1 second per division time scale in the Oscope tool that enables up to 10 seconds of time data to be visible in the Oscope display.

SignalScope 3.5 and SignalScope Pro 2.5 are both available for download on the App Store.

SignalScope Pro Screenshot

 

 

Download SignalScope 3.5

Download SignalScope Pro 2.5

 

Pop those balloons with RoomScope 1.3

A common request for RoomScope has been to directly capture room impulse response (IR) data using impulsive noise sources, such as balloons or starter pistols. RoomScope 1.3 now supports both single-channel and dual-channel IR data acquisition. The dual-channel capability has been built-in since version 1.0 of RoomScope, enabling the use of an omnidirectional loudspeaker and various excitation signals including broadband noise and frequency sweeps. The new single-channel IR acquisition tool can capture IR data directly by popping a balloon or firing a starter pistol within an acoustic space of interest. The input signal can be triggered in order to automatically begin data acquisition when the instantaneous input level crosses a user-defined threshold.

It should be noted that single channel analysis doesn’t mean that only one channel of data can be captured at one time. In fact, with an iPad and a multi-channel USB audio interface, it is possible to capture IR data from multiple microphones simultaneously (obviously, the mics and supporting cables, adapters, etc, would also be needed). Single channel analysis simply means that each input channel is treated independently from all other input channels. In contrast, dual-channel analysis means that a single measurement is based on data acquired from two input channels (using auto and cross-spectral analysis).

RoomScope 1.3 is now available for download on the App Store.

RoomScope 1.3 Screenshot

Download RoomScope 1.3

RoomScope and IOScope measure longer IRs and use 64-bit FFTs

RoomScope 1.2 and IOScope 2.3 arrived in the iOS App Store this week. Both apps now support impulse response measurements up to 16 seconds long and use double precision (64-bit) FFTs in their measurements. The maximum measurement length is dependent on the amount of memory available on the device, so 16-second measurements are currently only supported on the iPhone 5, iPad 3, and iPad 4. The previous generation of devices, including the iPod touch 5, supports 10-second measurements, and older devices are still limited to measurement durations of 5 seconds or less.

RoomScope 1.2 also offers the following additions:

  • Center time has been added to the list of calculated acoustic parameters.
  • All parameters are now calculated in low, mid, and high frequency bands, as defined by the ISO 3382 standard.
  • The calculation of the clarity and definition parameters (C and D) compensates for the delay of the whole and 1/3-octave band filters, as described in ISO 3382.
  • Raw IR data can now be excluded or included in CSV, MAT, and TXT file data exports.

RoomScope turns your iPad, iPhone, or iPod touch into a room acoustics measurement and analysis tool. With RoomScope, you can measure a room impulse response and then calculate reverberation time, early decay time, center time, clarity, and definition, as defined in the ISO 3382 standard. RoomScope also allows you to adjust the Schroeder decay curve integration limits with the touch of your finger and plot the calculated room parameters versus whole or 1/3-octave band center frequency.

RoomScope

 

Download RoomScope 1.2

IOScope brings true dual-channel transfer function and impulse response analysis to iOS. With IOScope, measure loudspeaker impedance, frequency response, and sensitivity. Measure a room impulse response. Tune a large sound reinforcement system, time-align a set of surround sound speakers, or optimize your home stereo. Determine the actual cutoff frequencies of your latest speaker crossover circuit, or teach your students the fundamentals of Fourier analysis of dynamic systems.

Measure frequency response magnitude and phase, coherence, and group delay. Time domain functions enable you to measure impulse response and auto/cross-correlation. IOScope includes a built-in signal generator for producing suitable excitation signals to analyze your system or device under test (DUT). See http://youtube.com/faberast for a video demo of loudspeaker impedance measurement.

 

Download IOScope 2.3

 

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.

 

Faber Acoustical brings room acoustics to iOS with RoomScope

Faber Acoustical is pleased to announce the immediate availability of RoomScope for iOS on the App Store.

RoomScope both measures and analyzes room impulse responses, calculating acoustical parameters such as reverberation time, early decay time, clarity and definition. Room acoustics parameters may even be calculated and displayed in whole or 1/3 octave frequency bands.

RoomScope offers users the ability to measure the acoustic response of a room, while viewing the impulse response, frequency response, or coherence dynamically as the measurement progresses. RoomScope’s dual-channel measurement capability enables users to employ built-in frequency sweeps or pseudorandom noise as a reference, or to work with arbitrary test signals from another source.

Room parameters, which are calculated by RoomScope using the integrated impulse response method of the ISO 3382 standard, include reverberation time (T20, T30, T60), early decay time, clarity (C50, C80, Cte), and definition (D50, D80, Dte). Users can use dual cursors within the plot of the squared impulse response to dynamically set integration limits for the decay curve.

Measurement data and calculated acoustic parameters may be exported to CSV, TXT, or MAT files. Impulse response data may also be stored in AIF, CAF, or WAV audio files. RoomScope additionally supports loading impulse response data via audio files created or opened in other apps, such as SignalScope Pro.

Download RoomScope

iPhone 5 screenshots

RoomScope Impulse Response iPhone5RoomScope Decay Curve iPhone5

 

iPad screenshots

RoomScope Impulse Response iPadRoomScope Decay Curve iPad

 

 

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.

Finally! iOS 6 kills the filter on headset and mic inputs!

So, iOS 6 has finally arrived and the biggest news for SoundMeter, SignalScope, and SignalScope Pro users may just be that the high-pass filter which used to plague the built-in microphone and headset microphone inputs now gets bypassed. This exciting improvement to iOS 6 will significantly improve the quality of acoustical measurements that can be made with the iPhone, iPad, or iPod touch, without requiring a dock connector accessory for audio input.

Below are 1/3-octave headset input frequency response comparisons for the various iOS devices that support iOS 6. More details regarding the headset input and built-in microphone will be presented in the days ahead.

Update (9/19/20120, 7:32 PM): It should be noted that these are electrical frequency response measurements. When making acoustical measurements, the overall frequency response will depend also on the microphone that is used.

iPhone 4S Before iOS 6/Now

iPhone 4S Headset Leq Pre-iOS 6  iPhone 4S Headset Leq iOS 6

iPhone 4 Before iOS 6/Now

iPhone 4 Headset Leq Pre-iOS 6  iPhone 4 Headset Leq iOS 6

iPhone 3GS Before iOS 6/Now

iPhone 3GS Headset Leq Pre-iOS 6  iPhone 3GS Headset Leq iOS 6

iPod touch 4 Before iOS 6/Now

iPod touch 4 Headset Leq Pre-iOS 6  iPod touch 4 Headset Leq iOS 6

iPad 3 Before iOS 6/Now

iPad 3 Headset Leq Pre-iOS 6  iPad 3 Headset Leq iOS 6

iPad 2 Before iOS 6/Now

iPad 2 Headset Leq Pre-iOS 6  iPad 2 Headset Leq iOS 6

 

iOS 6 is now highly recommended for all SoundMeter, SignalScope, and SignalScope Pro users.

 

 

IOScope 2.1 exports impulse responses to AIF, CAF, or WAV audio files

IOScope 2.1 is now available for download on the App Store.

IOScope room impulse response measurement

IOScope room impulse response measurement

IOScope 2 can now export normalized impulse response data to AIF, CAF, or WAV audio files. On iOS 5, or later, audio files can be previewed with IOScope or opened with other apps on the same device that can open these file formats. Of course, IOScope also allows for audio files to be transferred to a Mac or PC via iTunes File Sharing, or downloaded with a web browser via the built-in HTTP file server.

With IOScope, measure loudspeaker impedance, frequency response, and sensitivity. Measure a room impulse response. Tune a large sound reinforcement system, time-align a set of surround sound speakers, or optimize your home stereo. Determine the actual cutoff frequencies of your latest speaker crossover circuit, or teach your students the fundamentals of Fourier analysis of dynamic systems.

Measure frequency response magnitude and phase, coherence, and group delay. Time domain functions enable you to measure impulse response and auto/cross-correlation. IOScope includes a built-in signal generator for producing suitable excitation signals to analyze your system or device under test (DUT). The reference signal can be taken from the internal signal generator or from an external source (when using an external reference, a stereo audio input device, connected to the dock connector, is required).

IOScope also turns your iOS device into a platform for data acquisition, storing acquired data in CSV or tab-delimited text files, MAT-files, or images, including high-resolution PDF files, for later retrieval from your device.

What’s new in version 2.1?

  • Impulse responses can now be exported to AIFF, CAF, or WAV audio files. On iOS 5, audio files can be previewed within IOScope, or opened in other apps that support these file formats.
  • Frequency and time domain data can now be exported to CSV files, in addition to MAT-files and tab-delimited text files. CSV files can be opened directly in Numbers, or other spreadsheet apps that support it, from within IOScope.
  • The Excitation (signal generator) tab now supports the same color schemes as the analysis tools.
  • Other cosmetic improvements have been made to the user interface.

IOScope 2.1 requires iOS 4 or later, and is now available for download on the App Store for $74.99 (USD) in the Utilities category.

Learn more or download IOScope on the App Store

IOScope audio file export

IOScope audio file export

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.)
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