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

 

IOScope 3.0 Updated for iOS 7

As in recent updates to SignalScope Pro and SoundMeter, IOScope’s appearance has been completely revamped for iOS 7. IOScope 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.

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

– 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.

 

IOScope Screenshot iPhone 1 IOScope Screenshot iPhone 2 IOScope Screenshot iPhone 3

IOScope Screenshot iPhone 4 IOScope Screenshot iPhone 5

 

Download IOScope 3.0

 

 

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

Frequency Response Measurement with Electroacoustics Toolbox 3

Measuring the Frequency Response of Your Audio Device

One of the most powerful tools in Electroacoustics Toolbox is the Dual FFT Analyzer, which is capable of measuring system transfer functions and even indicating the quality of the measurement. This tutorial focuses on using the Dual FFT Analyzer to measure the frequency response of the audio device that you use to measure other systems and devices. If you want to measure the frequency response, or impulse response, of a listening room for example, that measurement will be affected by the quality of the audio interface that you are using to make the measurement. Therefore, it is important to know how your measurements will be influenced by your audio interface.

When measuring the properties of some device, like its frequency response, that device is commonly referred to as the “device under test” or DUT. In this case, the DUT is actually the audio device that would normally be used to measure some other device or system.

Measuring Your Audio Device

  1. Connect your device to your Mac (if necessary, you may want to consult your device’s user guide or owner’s manual).
  2. Using a patch cable that is appropriate for the device you are using, connect one or more outputs of the device to one or more inputs of the same device. Figure 1 demonstrates the connections using an Echo AudioFire4 FireWire interface. It is important to keep in mind that what will be measured in this tutorial is actually the combined frequency response of the input channel, the output channel, and even the patch cable between them.
    AF4
    Figure 1: 1/4″ plug patch cable

     

  3. Launch Electroacoustics Toolbox.
  4. Create a new project if one was not created automatically when the program launched.
  5. Click the Device IO button in the project window’s toolbar to open up the Device IO Setup window.
  6. In the Device IO Setup window, click on the name of the device you would like to measure in the Available Devices list. This will display the device’s properties in the lower portion of the window.
  7. Make sure the nominal sample rate is set high enough to capture the desired frequency range. For this tutorial, select 44100 or 48000 Hz.
  8. Create a new Dual FFT Analyzer tool. This can be accomplished by clicking the “+” button in the Dual FFT Analyzer row of the project toolbox, selecting Dual FFT Analyzer from the Tools menu in the project window’s toolbar, or by selecting New Dual FFT Analyzer from the Tools menu.
  9. Select the Live Inputs tab in the controls drawer at the bottom of the Dual FFT Analyzer window.
  10. Select the DUT (the device you previously configured in step 6) from the Input Device popup menu.
  11. In the measurement table below the Input Device menu, the first row will already be pre-filled for Measurement 1. For Measurement 1, change the channel in the Reference column to match the physical output channel connected in step 2, and change the channel in the Source column to match the input channel connected in step 2.
  12. If you connected multiple physical input/output channel pairs in step 2, click the “+” button above the measurement table to add an additional measurement for each additional channel pair and configure the Reference and Source channels as in the previous step.
  13. In the FFT tab of the Dual FFT Analyzer’s controls drawer, set the number of spectral lines to a value that will provide the frequency resolution you need. For the purposes of this tutorial, select 4410 spectral lines if your DUT’s sample rate is 44100 Hz or 4800 lines if your sample rate is 48000 Hz. The frequency resolution of your measurement can be determined by the selected frequency span (which is dependent on the sample rate) and the number of spectral lines. You can calculate the frequency resolution by dividing the frequency span by the number of lines (if guardbanding is turned off). For example, if the selected frequency span is 24000 Hz, and the number of lines is 4800, the frequency resolution will be 24000/4800 = 5 Hz. You can also view the current frequency resolution of the analyzer inside the analyzer’s info drawer, which slides out of the right-hand side of the analyzer’s window.
    DFFT FFT
    Figure 2: Dual FFT Analyzer FFT Parameters
  14. Click on the Display tab of the Dual FFT Analyzer’s controls drawer to choose which kind of measurement to display. The name of each measurement can be edited by double clicking on it within the Name column of the table, either in the Display tab or in the Live Inputs tab.
  15. From the Function popup menu, select Transfer Function (H1) Mag to measure the magnitude of the DUT’s frequency response. Figure 3 shows the Function configuration for measuring the Echo AudioFire4.
    DFFT Display
    Figure 3: Dual FFT Analyzer Function Selection
  16. If you are only using one output channel of the device, you can select that channel in the output channel popup menu in the Excitation tab of the Dual FFT Analyzer’s controls drawer. Then jump to step 22. Otherwise, follow steps 17 through 21 to configure as many Signal Generators as necessary to measure all the input/output channel pairs connected in step 2.
  17. Create a new Signal Generator tool.
  18. Select your DUT in the Output Device popup menu of the Signal Generator’s signal drawer (on the lefthand side of the Signal Generator window).
  19. Select the output channels corresponding to the physical output channels that you connected in step 2. Select the first output channel in the Left Output Channel box, and the second output channel in the Right Output Channel box. If you have connected more than two output channels for a multichannel measurement, you will need to create a new Signal Generator tool for each pair of output channels to be measured.
  20. Click on the Swept Sine (Chirp) tab in the Signal Generator window to display controls for establishing a frequency sweep excitation signal. Configure the swept sine generator similarly to that shown in Figure 4. The Upper Frequency should be half the selected sample rate, which corresponds to the Nyquist frequency.
  21. Click the “On” check box to enable the swept sine generator.
    SigGen Sweep
    Figure 4: Signal Generator Log Sweep Configuration
  22. Select the Dual FFT Analyzer window again.
  23. Go ahead and save the project now.
  24. Create a new Meter Bridge tool.
  25. Select your device in the Input Device popup menu of the Meter Bridge’s controls drawer (in the Live Inputs tab).
  26. Start the Meter Bridge.
  27. Make sure the Peak level type is selected in the Meter Bridge’s controls, then look to be sure none of the input channels are in danger of clipping (colored red at the top of the meter bar). If any of the input signal levels are too high, reduce the level in the Signal Generator (or the Excitation tab of the Dual FFT Analyzer).
  28. Start the Dual FFT Analyzer, either by clicking the start icon in the window’s toolbar, or by selecting Start Analyzer from the Control menu (or by typing Command-R).
  29. If you have one or more Signal Generator tools in your project, you can start all of them by selecting Start All Tools from the Control menu.
  30. After everything is running and the measurements have stabilized, you can stop the tools. (If you have Signal Generators running and choose to stop the tools individually, it would be best to stop the Dual FFT Analyzer tool first.) Figure 5 shows a plot, created by the Dual FFT Analyzer, which shows the frequency response of the Echo AudioFire4. The frequency response of the AudioFire4 is quite flat between 20 Hz and 20 kHz.
  31. Now that the frequency response magnitude has been measured, other measurements are just a menu selection away. Go back to the Display tab of the Dual FFT Analyzer and take a look at the different functions in the popup menu. All the data necessary to compute the various functions has already been acquired, so there is no need to run the analyzer again to measure the phase response. Once you have measured one of those quantities, you have essentially measured them all. All that’s left to do is change the selection in the popup menu.
  32. Capture your measurement, either by clicking the capture button in the Dual FFT Analyzer’s toolbar, or by choosing Capture Data from the Control menu.
  33. Save your project so you can review your measurement or export the data at another time.
    Figure 5: Echo AudioFire4 Frequency Response

     

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.

 

 

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.)

SignalScope 3 and SignalSuite 4 Complete Mac App Store Transition

Both SignalScope 3.0 and SignalSuite 4.0 became available for download on the Mac App Store, today. The availability of these two apps marks the successful transition of all of Faber Acoustical’s Mac apps to the new App Store. Both apps feature an improved user interface and require Mac OS X, version 10.6. Use of the Mac App Store requires at least Mac OS 10.6.6.

SignalScope 3 builds on SignalScope’s tradition of award-winning design and precision measurement capabilities by building on advanced technology developed for Faber Acoustical’s flagship product, Electroacoustics Toolbox.

SignalScope is a modularized, multi-channel dynamic signal analyzer and data acquisition platform for Mac. It brings powerful tools to the Macintosh platform for multi-channel, audio-band data acquisition and real-time analysis of electrical, acoustical, and electroacoustic signals and systems. The software is designed to work with any Mac-compatible audio hardware and supports multiple channels of 8, 16, 24, or 32-bit data with sample rates as high as the hardware will support.

New functionality in SignalScope includes the option to perform arithmetic operations, such as addition, subtraction, and multiplication, on two arbitrary input channels of an audio input device. Users can also specify arbitrary FFT lengths and view live spectrogram data with a logarithmic frequency scale. Two of each type of analysis tool can be opened and operated simultaneously.

Learn more about SignalScope 3.0

Download SignalScope from the Mac App Store

Download SignalScope Trial from FaberAcoustical.com

Version 4 continues SignalSuite’s tradition of offering tremendous flexibility in an audio test signal generator. The new version adds support for up to two stereo signal generators to be operated simultaneously.

Audio Unit generator support opens up endless possibilities for additional signal types. This includes signals stored in standard audio files, which can be now played within SignalSuite by using the AUAudioFilePlayer plug-in included with Mac OS X. It also opens up the option to play back signals sent across a network from another computer, via the AUNetSend/AUNetReceive plug-ins, which are also included with Mac OS X.

Learn more about SignalSuite 4.0

Download SignalSuite from the Mac App Store

Download SignalSuite Trial from FaberAcoustical.com

 

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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