The APx LabVIEW Driver is a collection of Virtual Instruments (VIs) that provide LabVIEW users with most of the functionality available in the APx500 Application Programming Interface (API) using high level, LabVIEW-typical subVIs. With the driver, you can quickly and efficiently develop APx applications with clean, concise LabVIEW code. Please note that the LabVIEW Driver is specific for each release of APx500 (e.g., APx LabVIEW Driver v5.0.x can only be used with APx500 Software v5.0.x). Requires LabVIEW 2012 or higher.

The APx LabVIEW Driver is a collection of Virtual Instruments (VIs) that provide LabVIEW users with most of the functionality available in the APx500 Application Programming Interface (API) using high level, LabVIEW-typical subVIs. With the driver, you can quickly and efficiently develop APx applications with clean, concise LabVIEW code. Please note that the LabVIEW Driver is specific for each release of APx500 (e.g., APx LabVIEW Driver v5.0.x can only be used with APx500 Software v5.0.x). Requires LabVIEW 2012 or higher.

The WaveReader DLL provides functions that can be called from an external program, to enable transfer of acquisition data from an APx analyzer to that program in near real time. Any .NET compliant language such as C#, VB.NET, or LabVIEW can make use of it.

An Agilent VEE example that opens APx500, makes settings, and runs an acquisition. For more details about controlling APx500 using VEE, read the article "Using APx with VEE and MATLAB." After downloading, open in a text editor and modify the .NET references to refer to your current version of APx500.

IronPython is a version of Python that can interface with .NET Assemblies. This download includes an APx Project and a Python code sample that controls APx500 via the APx API.

The LabVIEW DAQ Driver for APx515 communicates directly with APx515 hardware and does not utilize the APx500 measurement software or API. Its functionality is similar to NI DAQmx, making it possible to upgrade an existing test system that uses DAQmx to utilize the APx515 with reduced effort. Requires LabVIEW 2012 or later, and VIPM 2014 or later for installation.

IMPORTANT: LabVIEW DAQ Driver for APx515 is ONLY compatible with Legacy APx515 analyzers. It does not work with B Series APx515 analyzers.

If you are looking for a LabVIEW driver that communicates with the APx500 software through the APx500 .NET API, then download the APx LabVIEW .NET Driver instead.

The APx LabVIEW Driver is a collection of Virtual Instruments (VIs) that provide LabVIEW users with most of the functionality available in the APx500 Application Programming Interface (API) using high level, LabVIEW-typical subVIs. With the driver, you can quickly and efficiently develop APx applications with clean, concise LabVIEW code. Please note that the LabVIEW Driver is specific for each release of APx500 (e.g., APx LabVIEW Driver v5.0.x can only be used with APx500 Software v5.0.x). Requires LabVIEW 2010 or higher.

A guide to using the APx500 API, updated for the current version.

Resources for API developers. Includes VB.NET and C# templates and example code, C++ examples, LabVIEW examples, and the APx Wavereader dll. Documentation includes Intro to Programming the APx500 API and the APx API Browser. The APx LabVIEW driver is a separate download.

Included in this download:

What's New in the APx500 API
Introduction to Programming the APx500 API
API Browser application

NOTE: APx API Developer Tools are specific to each release of APx500 (e.g., APx API Developer Tools v4.2.x can only be used with APx500 Software v4.2.x).

APx Digital Serial I/O configuration files for A/D, D/A, and sample rate converters. Simplifies configuring the analyzer. Requires: 1) APx500 measurement software and 2) an APx instrument with the DSIO option installed.

Datasheet for the PDM 16 input module, compatible with APx52x, APx555 and APx58x audio analyzers. PDM 16 can be installed in either B Series or Legacy APx audio analyzers (in the latter case, instruments manufactured after August 2012).

Note: requires APx500 audio measurement software version 5.0.3 or later.

APx555 Datasheet - High-Performance, 2-Channel Audio Analyzer

A single sheet description of APx Electro-Acoustic software options, including Thiele-Small characterization, Rub & Buzz detection and Loudspeaker Production Test.

Datasheet for APx PESQ and POLQA software options

Datasheet for the APx500 Series analyzer PDM module. Compatible with APx555, APx52x Series, and APx58x Series analyzers.

APx’s Legacy Bluetooth module, with built-in radio and software stack, allows engineers to measure their Bluetooth devices directly. All Bluetooth controls are integrated into the analyzer software and APx supports A2DP, HFP 1.6, and AVRCP profiles. Codec support includes SBC, aptX, CVSD, and wideband speech (mSBC).

Please also see the APx Bluetooth Duo module.

Audio Precision's new Digital Serial I/O for APx audio analyzers provides multichannel, chip-level connectivity for designers of HDMI receiver/ transmitter chips, converters and other micro-components. Innovations include 8 channels of simultaneous audio data, independent clocks, buffered oscilloscope monitors, and built-in support for left or right justified, I2S and DSP formats.

Version 8.0.4 is the current release of APx500 audio measurement software.

APx500 software version 8.0.4 adds new enhancements suited to a wide range of audio test applications, whether analog, digital, or acoustic:

• THD+N Level and THD+N Ratio results with filtering options and delay compensation added to the following measurements when using a Fast Sweep stimulus:
  - Acoustic Response
  - Continuous Sweep
  - Loudspeaker Production Test
• Enhancements to Windowing and Masking controls for SoneTrac Rub & Buzz measurement results.
• Improvements to SysCheck2 interoperability and support for additional SysCheck2 microphones.
• Graph points for data grid display, data export and data import can be set to a wider range of values (from 1-100,000 instead of the previous limited options between 10-500).
• Enhancements to improve UI application response.

New analyzers include one year of software maintenance, licensing that instrument for APx version 9.0 when it is released, as well as any minor releases that occur between versions 8.0 and 9.0. Release 8.0.4 is compatible with all analyzers in the APx500 Series, however an APx KeyBox is required to run all software on Legacy APx analyzers.

IMPORTANT: Beginning with version 5.0, a paid license is required to run each major release (e.g., v5.0, v6.0, etc.) of APx500 audio measurement software.

Software Licensing FAQ

Additional information regarding APx500 measurement software:

1. AP Software and Windows Compatibility chart
2. APx500 software v5.0 and later requires the Windows 10 or 11 64-bit operating system.
3. This download includes the Microsoft .NET Framework version 4.7, and is suitable for installation on PCs that are not connected to the Internet and do not already have version 4.7 installed.

Version 7.1 is the current release of APx500 audio measurement software.

APx500 software version 7.1 adds new enhancements suited to a wide range of audio test applications, whether analog, digital, or acoustic:

• Support for GRAS SysCheck2-capable microphones
• Enables the use of Fast Sweep in open loop testing scenarios
• Expands FFT analysis capabilities
• Adds Transfer Function to Bench Mode

New analyzers include one year of software maintenance, licensing that instrument for APx version 8.0 when it is released, as well as any minor releases that occur between versions 7.0 and 8.0. Release 7.1 is compatible with all analyzers in the APx500 Series, however an APx KeyBox is required to run v7.0 on Legacy APx analyzers.

IMPORTANT: Beginning with version 5.0, a paid license is required to run each major release (e.g., v5.0, v6.0, etc.) of APx500 audio measurement software.

Software Licensing FAQ

Additional information regarding APx500 measurement software:

1. AP Software and Windows Compatibility chart
2. APx500 software v5.0 requires the Windows 10 64-bit operating system.
3. This download includes the Microsoft .NET Framework version 4.5, and is suitable for installation on PCs that are not connected to the Internet and do not already have version 4.5 installed. NOTE: .NET 4.5 does not support Microsoft Windows XP.

Version 7.1 is the current release of APx500 audio measurement software.

APx500 software version 7.1 adds new enhancements suited to a wide range of audio test applications, whether analog, digital, or acoustic:

• Support for GRAS SysCheck2-capable microphones
• Enables the use of Fast Sweep in open loop testing scenarios
• Expands FFT analysis capabilities
• Adds Transfer Function to Bench Mode
• The handling of units of measure is now more integrated, improving the presentation of your input units. Scale any input in either the native unit domain of that physical input or in Volts, FS, Pascals, or Amps.

New analyzers include one year of software maintenance, licensing that instrument for APx version 8.0 when it is released, as well as any minor releases that occur between versions 7.1 and 8.0. Release 7.1 is compatible with all analyzers in the APx500 Series, however an APx KeyBox is required to run v7.1 on Legacy APx analyzers.

IMPORTANT: Beginning with version 5.0, a paid license is required to run each major release (e.g., v5.0, v6.0, etc.) of APx500 audio measurement software.

Software Licensing FAQ

Additional information regarding APx500 measurement software:

1. AP Software and Windows Compatibility chart
2. APx500 software v7.1 requires the Windows 10 64-bit operating system.
3. This download is suitable for most users. If Microsoft .NET version 4.5 is not already on your PC, it will be downloaded during the installation.
4. For PCs that do not have .NET version 4.5 installed, and are not connected to the Internet, download the full installer instead (APx500 Measurement Software (with .NET)) NOTE: .NET 4.5 does not support Microsoft Windows XP.

Describes new features in the latest release, v5.0, of the APx500 measurement software. Additional information can be found in the latest ReadMe, which is included in the software download.

FirmwareUpdateB4AIv2.0 is a firmware patch.

If you have purchased a new APx555 analyzer on or after June 22, 2016, with serial number 11255 or greater, and you wish to operate this analyzer with older versions of APx500 (specifically v4.0, v4.1 or v 4.2.1), you must download and install this patch. Note that versions previous to v4.0 do not support APx555 hardware under any circumstances.

This patch is not required if you are using the current version of APx500 software, version 4.3, which has been provided with your instrument and is available for download from this web site.

Describes new features in the latest release of the APx500 measurement software. Additional information can be found in the latest Read Me.

This compressed file contains a copy of the PESQ speech waveforms installed with the APx500 audio measurement software. It is provided as a convenience for APx500 users who want the ability to download these files from the web.

Please note: performing PESQ measurements with an APx audio analyzer does require the PESQ Perceptual Audio Test (SW-PESQ) software option. More information on perceptual audio testing with APx.

This compressed folder contains audio test signals required to do the most common tests for audio quality in several formats:

(1) Linear PCM .wav files at 44.1 kHz sample rate and 16 bits (sub-folder PCM_44_16)

(2) Linear PCM .wav files at 48 kHz sample rate and 24 bits (sub-folder PCM_48_24)

(3) Dolby Digital 5.1 encoded .ac3 files (sub-folder DD_5.1)

(4) Dolby Digital Plus 5.1 encoded .ec3 files (sub-folder DD+_5.1)

(5) dts Digital Surround 5.1 encoded .ds.dtshd files (sub-folder dts_5.1)

In order to test the audio quality of devices like set-top boxes, special audio test streams of known quality must be played from the set-top box into an audio analyzer. This usually requires that the audio streams be encoded into a format that can be streamed from the set-top box over HDMI,S/PDIF or TOSLINK. The audio test signals in this folder are provided for the convenience of set top box manufacturers who wish to test with Audio Precision at HDMI Plugfest. If you are a set top box manufacturer and you wish to test your device with Audio Precision at HDMI Plugfest, please arrange to have these audio test streams encoded and loaded onto your device before coming to Plugfest.

A comprehensive set of MP4 video files with audio encoded in AAC, Dolby Digital 2.0, Dolby Digital 5.1, and Dolby Digital Plus 5.1 formats. Accompanies
Technote 116: Testing Smartphones and Tablets, which is a separate download.

APx Smartphone and Tablet Audio Test Files is also available.

A comprehensive set of audio test files at 8k, 16k, 44.1k, and 48k sample rates for testing smartphones and tablets. Accompanies
Technote 116: Testing Smartphones and Tablets, which is a separate download.

APx Smartphone and Tablet Video Test Files is also available.

APx FM MPX-RDS Waveforms 75µs (North America) contains a series of FM multiplex and RDS encoded waveforms for FM radio receiver testing with the APx Series analyzers. The test streams are versions of the stereo .wav files that can be created with the Audio Precision Waveform Generator Utility (WfmGeneration.exe), also available for download.

Copy the folder to your PC and load the desired file using the generator waveform browser inside the APx500 application. Download Technote 105: FM Radio Receiver Testing with APx Audio Analyzers for a discussion on FM testing.

APx FM MPX-RDS Waveforms 50µs (except North America) contains a series of FM multiplex and RDS encoded waveforms for FM radio receiver testing with the APx Series analyzers. The test streams are versions of the stereo .wav files that can be created with the Audio Precision Waveform Generator Utility (WfmGeneration.exe), also available for download.

Copy the folder to your PC and load the desired file using the generator waveform browser inside the APx500 application. Download Technote 105: FM Radio Receiver Testing with APx Audio Analyzers for a discussion on FM testing.

The APx DTS Generator Waveforms support the APx500 generator waveform feature and are encoded in the various DTS surround sound formats. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

The APx DTS Generator Waveforms support the APx500 generator waveform feature and are encoded in the various DTS surround sound formats. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

The APx DTS Generator Waveforms support the APx500 generator waveform feature and are encoded in the various DTS surround sound formats. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

The APx Dolby Generator Waveforms support the APx500 generator waveform feature. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

Download of this file is restricted to Dolby Licensees. If you are a Dolby licensee, please contact Audio Precision Technical Support supplying your Dolby License and AP web site login name to obtain download permissions.

The APx Dolby Generator Waveforms support the APx500 generator waveform feature. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

Download of this file is restricted to Dolby Licensees. If you are a Dolby licensee, please contact Audio Precision Technical Support supplying your Dolby License and AP web site login name to obtain download permissions.

The APx Dolby Generator Waveforms support the APx500 generator waveform feature. Copy the folders to your PC and browse to the desired file from the Generator Waveform browser inside the APx500 application.

Notes: These files are similar to the files of the same name and format available on the APx-BD1 Blu-ray disc. Some files have been shortened to accommodate the memory limitation for the generator waveform feature. A few files that could not be shortened have been omitted.

Installation instructions and full specifications for the APx555 Audio Analyzer. AP specifications in hard copy booklets & brochures can be out of date. The specifications documents available for download from our Web site have the most current and correct information. If there is a conflict between printed and online specifications, the online version is the prevailing document.

Enables an APx500 audio analyzer to measure wow and flutter, according to standard "AES 6-2008 - Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment" (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

Enables an APx500 audio analyzer to measure wow and flutter, according to standard "AES 6-2008 - Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment" (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

Set of MATLAB functions for audio applications such as reading and writing waveforms and filters for 2700, ATS-2, and APx500

Enables an APx500 audio analyzer to measure wow and flutter, according to standard "AES 6-2008 - Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment" (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

The Waveform Generator Utility (APxWfmGenerator.exe) allows you to generate .wav files for a wide range of test signals, with selectable sample rates, bit depths and channel counts.

You are free to copy this utility to other computers or media, where you can generate the audio files you may need for external source testing.

Note that the version number of this utility does not correspond to APx500 software versions and APx500 is not required.

Enables an APx500 audio analyzer to measure wow and flutter, according to standard "AES 6-2008 - Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment" (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

This APx utility facilitates testing of small loudspeakers according to requirements of the South Korea Telecommunications Technology Association (TTA) Standard number TCB-0054(00), "TTA Verified Testing Criteria for Micro/Slim Speakers" using an Audio Precision APx500 Series audio analyzer.

Note that the version of this utility must match the version of APx500 that you are using it with.

Allows an APx500 Series Analyzer to measure acoustic noise or sound in the environment, taking the place of a handheld sound level meter. Using the
analyzer adds the capability to perform spectrum analysis, and to visualize the character of the sound signal over time. The latter is especially valuable when measuring non-steady-state sounds, such as a pulsating alarm. Technote 113, included, describes the theory and how to use the utility.

Power Supply Rejection Ratio (PSRR) is a measure of a device's ability to reject noise from the supply used to power it.

Download includes the utility and TechNote 106: Measuring Power Supply Rejection Ration (PSRR). The utility version must match the version of APx500 that you are running.

The APx Polar Plot Utility is a Windows application for making polar measurements of loudspeakers or microphones with an APx500 audio analyzer and for creating 2-dimensional polar dispersion plots from the measured data.

The APx Polar Plot utility also requires the SPK-RD software option to be installed on the connected APx audio analyzer. If you require a SPK-RD software option, please contact your Audio Precision sales representative.

Updated to address a compatibility issue with Windows 10. Also includes an updated user guide.

Note: This version of the APx Polar Plot Utility is compatible with APx500 audio measurement software versions 4.4, 4.4.1 and 4.4.2. Updated in January 2018 to remove a beta restriction.

The output impedance of a device can easily be calculated by measuring its output voltage with and without a known load attached. The APx Output Impedance Measurement Utility simplifies the procedure by calculating and graphing the results. See the accompanying knowledge base article for an explanation and instructions.

The version number of this utility must match the version of the APx software that you are running.

Measures jitter at the receiving end of an AES3/SPDIF connection by using a special J-test stimulus signal and analyzing the analog output spectrum. Displays graphs showing the FFT spectrum, the jitter spectral density, and the integrated jitter, in addition to a total jitter value. Tools are included for manipulating the graphs, exporting data, and printing.

Download includes the utility, J-test stimulus waveforms, and instructions. The utility version must match the version of APx500 that you are running.

The APx EQ .wav Files Utility lets you apply equalization to generator source .wav files. When given an original .wav file and an EQ curve file, it creates a new EQed .wav file. Includes both graphic interface and command line versions. The utility is useful to EQ PESQ generator files for a given stimulus speaker.

Important Notes:

1. Please review the utility instructions prior to downloading and installing the utility.
2. Any version of APx500 may be used with this utility. Utility version numbers do not correspond to APx500 versions.

The APx500 CSD Utility is a Windows application for making a Cumulative Spectral Decay (CSD) plot, sometimes referred to as a waterfall plot, from the measured impulse response of a loudspeaker.

The APx CSD utility also requires the SPK-RD software option to be installed on the connected APx audio analyzer. If you require a SPK-RD software option, please contact your Audio Precision sales representative.

Tests portable audio players and headphones packaged as a set, and as individual components, for compliance with the BS EN 50332 standard. Works with any APx Series analyzer. The version of APx500 software must match the utility version. Includes Technote 107 with full instructions.

This utility creates sine burst waveforms and then saves them and/or uploads them into the APx generator. Burst waveforms can be useful in testing a number of properties, including power supply transient response and reserve, meter ballistics, and compressor/limiter behavior.

Automated self-test for all APx500 Series instruments. Run this test to confirm proper operation and before sending an instrument in for service.

Audio Precision's Smartphone audio test app for Android allows for full testing of audio pathways, including Bluetooth HFP and A2DP, without initiating a call over the network. It supports Android versions 4, 5, 6, 7, 8, and 9.

This zip file includes a copy of Technote 120, which describes and explains the use of the APx Smartphone app for Android-based devices.

NOTE: this app requires an APx analyzer and a PC running APx500 measurement software v4.6 or later.

Automated self-test for all APx500 Series instruments. Run this test to confirm proper operation and before sending an instrument in for service.

Enables an APx500 audio analyzer to measure wow and flutter, according to standard "AES 6-2008 - Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment" (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

This APx utility facilitates testing of small loudspeakers according to requirements of the South Korea Telecommunications Technology Association (TTA) Standard number TCB-0054(00), "TTA Verified Testing Criteria for Micro/Slim Speakers" using an Audio Precision APx500 Series audio analyzer.

Note that the version of this utility must match the version of APx500 that you are using it with.

Allows an APx500 Series Analyzer to measure acoustic noise or sound in the environment, taking the place of a handheld sound level meter. Using the
analyzer adds the capability to perform spectrum analysis, and to visualize the character of the sound signal over time. The latter is especially valuable when measuring non-steady-state sounds, such as a pulsating alarm. Technote 113, included, describes the theory and how to use the utility.

Power Supply Rejection Ratio (PSRR) is a measure of a device's ability to reject noise from the supply used to power it.

Download includes the utility and TechNote 106: Measuring Power Supply Rejection Ration (PSRR). The utility version must match the version of APx500 that you are running.

The APx Polar Plot Utility is a Windows application for making polar measurements of loudspeakers or microphones with an APx500 audio analyzer and for creating 2-dimensional polar dispersion plots from the measured data.

The APx Polar Plot utility also requires the SPK-RD software option to be installed on the connected APx audio analyzer. If you require a SPK-RD software option, please contact your Audio Precision sales representative.

The output impedance of a device can easily be calculated by measuring its output voltage with and without a known load attached. The APx Output Impedance Measurement Utility simplifies the procedure by calculating and graphing the results. See the accompanying knowledge base article for an explanation and instructions.

The version number of this utility must match the version of the APx software that you are running.

Measures jitter at the receiving end of an AES3/SPDIF connection by using a special J-test stimulus signal and analyzing the analog output spectrum. Displays graphs showing the FFT spectrum, the jitter spectral density, and the integrated jitter, in addition to a total jitter value. Tools are included for manipulating the graphs, exporting data, and printing.

Download includes the utility, J-test stimulus waveforms, and instructions. The utility version must match the version of APx500 that you are running.

Converts FFT spectra to fractional octave spectra. Includes instructions which discuss the theory behind the conversion.

The APx500 CSD Utility is a Windows application for making a Cumulative Spectral Decay (CSD) plot, sometimes referred to as a waterfall plot, from the measured impulse response of a loudspeaker.

The APx CSD utility also requires the SPK-RD software option to be installed on the connected APx audio analyzer. If you require a SPK-RD software option, please contact your Audio Precision sales representative.

This utility creates sine burst waveforms and then saves them and/or uploads them into the APx generator. Burst waveforms can be useful in testing a number of properties, including power supply transient response and reserve, meter ballistics, and compressor/limiter behavior.

Tests portable audio players and headphones packaged as a set, and as individual components, for compliance with the BS EN 50332 standard. Works with any APx Series analyzer. The version of APx500 software must match the utility version. Includes Technote 107 with full instructions.

The Waveform Generator Utility (APxWfmGenerator.exe) allows you to generate .wav files for a wide range of test signals, with selectable sample rates, bit depths and channel counts.

You are free to copy this utility to other computers or media, where you can generate the audio files you may need for external source testing.

Note that the version number of this utility does not correspond to APx500 software versions and APx500 is not required.

Automated self-test for all APx500 Series instruments. Run this test to confirm proper operation and before sending an instrument in for service.

Automates procedure of leveled acoustic output when testing acoustic input devices such as microphones, as fully described in Technote 127.

Enables an APx500 audio analyzer to measure wow and flutter, according to standard “AES 6-2008—Method for Measurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment” (IEC 60386 Weighted). Includes an FFT of the demodulated waveform, as well as an unweighting option.

The Waveform Generator Utility (APxWfmGenerator.exe) allows you to generate .wav files for a wide range of test signals, with selectable sample rates, bit depths and channel counts.

You are free to copy this utility to other computers or media, where you can generate the audio files you may need for external source testing.

Note that the version number of this utility does not correspond to APx500 software versions and APx500 is not required.

The APx Waveform Computes Utility extends the capabilities of APx500 by making Fast RMS (root mean square) measurements. Additionally, it utilizes Fast RMS for a number of useful tasks: audio/video synchronization, dropout detection, and pop/click detection. Download includes utility, instructions, and example project file.

The APx500 CSD Utility is a Windows application for making a Cumulative Spectral Decay (CSD) plot, sometimes referred to as a waterfall plot, from the measured impulse response of a loudspeaker.

The APx CSD utility also requires the SPK-RD software option to be installed on the connected APx audio analyzer. If you require a SPK-RD software option, please contact your Audio Precision sales representative.

This APx utility facilitates testing of small loudspeakers according to requirements of the South Korea Telecommunications Technology Association (TTA) Standard number TCB-0054(00), "TTA Verified Testing Criteria for Micro/Slim Speakers" using an Audio Precision APx500 Series audio analyzer.

Note that the version of this utility must match the version of APx500 that you are using it with.

Produces a separate trace for each harmonic H2 through H10 (can be extended to H20), as both a level and as a ratio, and displays them all on one graph. Each harmonic can easily be enabled or hidden. Makes use of the Export Data and Import Data steps in the automated project sequencer. I/O connectors and measurement bandwidth should be set in Signal Path Setup before running. This project will open in APx500 v3.0 or later.

Splice is a CLI utility that combines separate LF and HF measurements into a single full frequency response result.

This utility for APx analyzers allows you to make an impedance vs frequency sweep across a loudspeaker, and then see the graph and data results directly in ohms. Clicking Help in the utility will display the complete instructions, including a discussion of the theory behind it. It can utilize the built-in source resistor on APx analyzers to make impedance measurements.

NOTE:This utility is only compatible with APx500 Software v3.3 or earlier. For users with APx500 v3.4 or later, options APX-SW-SPK-RD&l and APX-SW-SPK-PT provide a range of acoustic measurements, with SPK-RD including Thiele-Small characterization. An impedance-only alternative is also available for download and is compatible with APx500 v3.4 and later, please see the APx Speaker Impedance Measurement Project. This project requires an external sense resistor and uses the constant voltage method.

This project measures loudspeaker impedance using the constant voltage method.

Complete instructions and explanation are in the KB article Measuring Loudspeaker Impedance Using APx Derived Measurement Results.

An external sense resistor is required for this project. The
APx Speaker Impedance Measurement Utility also available for download, can utilize the built-in source resistor in APx analyzers.

Allows an APx500 Series Analyzer to measure acoustic noise or sound in the environment, taking the place of a handheld sound level meter. Using the
analyzer adds the capability to perform spectrum analysis, and to visualize the character of the sound signal over time. The latter is especially valuable when measuring non-steady-state sounds, such as a pulsating alarm. Technote 113, included, describes the theory and how to use the utility.

This APx project and related files demonstrates how to run an external program from APx500. Includes THD+N measurement and Stepped Frequency Sweep measurements. The project file calls the Goldwave audio editor program, so you will either need to install Goldwave, or substitute another audio player with a command line interface. Accompanies the kb article "Running an external program from APx500," which gives a complete explanation.

The files created while doing "Tutorial A: Making a Custom layout from the Default layout" in the APx500 program Help. Use these files if you wish to skip Tutorial A and proceed with Tutorials B and C.

The APx Repeat Selected Measurement Utility allows you to continuously repeat any selected APx500 measurement. This is useful when adjusting a device, circuit, or component on the bench and you want to monitor changes as you make them in real time.

Download includes installer and instructions. The utility version must match the version of APx500 that you are running.
3.3 is the last version of this utility. Repeat capability is already included in Bench mode in APx500 v4.0 and later.

Power Supply Rejection Ratio (PSRR) is a measure of a device's ability to reject noise from the supply used to power it.

Download includes the utility and TechNote 106: Measuring Power Supply Rejection Ration (PSRR). The utility version must match the version of APx500 that you are running.

Document describes in detail the features and operation of the APx PDM module. The module is an available option for the APx555, APx52x Series and APx58x Series Audio Analyzers.

Discusses writing and reading good audio specifications. Guidelines are provided, then key specifications for two classes of audio device are examined for correct expression and form, with examples of real-world specs for comparison.

This reference handbook is a practical, hands-on guide for workers in all phases of the audio field. It covers basic tools and techniques, common environments for audio testing, application of these techniques to common audio devices, the typical ranges of performance to expect in different devices, and a glossary of terms and key specifications used in audio measurement. 178 pages Written by Bob Metzler.

Audio analyzers are optimized to make high quality measurements up through their maximum specified bandwidths. The presence of significant energy above these bandwidths can have a profound effect on the audio measurements and possibly induce errors. This white paper provides valuable information on avoiding the possibility of errors when testing digital to analog converters and other audio devices that contain significant energy above the audio band. Written by Bruce Hofer

Switch-mode audio power amplifiers are becoming increasingly popular due to their smaller size, lower weight, and improved efficiency. Their advantages are obvious in low power battery operated personal audio players and laptop computers. However they are also progressively displacing more traditional linear designs in mainstream applications such as home entertainment systems, automotive sound systems, and professional installations where high quality audio is important. Measuring the performance of switch-mode amplifiers presents some new and unique challenges. They inherently generate ultra-sonic artifacts and spurious signals with slew rates that can provoke non-linear behavior within the input stages of high quality audio test and measurement equipment. Absolutely worthless and inaccurate results can result unless effective measures are taken to prevent this non-linear behavior. Written by Bruce Hofer.

Automatic Gain Control (AGC) is a signal processing technique typically used to limit the audio dynamic range in applications ranging from hearing aids to broadcasting. AP’s latest plugin enables the characterization of attack-and-release (recovery) times for AGC-enabled devices and allows the user to perform the tests according to several different standards, from IEC 60268-8 for general purpose AGC devices to IEC 60118-2 and ANSI S3.22 for hearing aids. Test settings can also be customized when using the IEC 60268-8-based measurement.

The plugin is compatible with any model APx500 Series analyzer and requires APx audio measurement software, version 4.3 or later.

For designers of public address, flight recorder and police/fire/emergency communications systems, the APx Speech Transmission Index (STI) plugin is a software add-on for the APx500 that provides a STIPA measurement and Speech Level measurement conforming to international standard IEC 60268-16 (2011).

Technote 128: Speech Transmission Index Measurement with APx Audio Analyzer

NOTES:

• The STI plugin is a software option and requires the purchase of an iButton (APX-SW-STI) for measurement functionality. Download and installation of the plugin, without an iButton, enables the measurement in demo mode only.
• APx STI Plugin v1.1 requires v4.2.1, v4.3 or v4.4.2 of APx500 audio test software. (For versions 4.5 or later of APx500 audio software, please use APx STI v2.0.)

USB driver update for users of APx500 v2.3 - 3.4 running on Windows Vista, 7, and 8. Apply this update if you encounter the following symptoms:
1) During installation of APx500 you receive one or both of the following warnings:

- User Account Control (UAC) warning: "Do you want to allow the following program from an unknown publisher to make changes to this computer?"

- Windows Security warning: "Windows can't verify the publisher of this driver software."

2) APx500 fails to recognize an attached APx analyzer (runs only in demo mode).

Download this update and run it after installation of APx500 and then power-cycle the attached APx analyzer.

In collaboration with Dolby engineers, Audio Precision has developed APx-based test solutions, available to Dolby licensees, to support both the Dolby Digital Plus Consumer Decoder SDK and the MS11 Multistream Decoder SDK. In the case of Dolby Digital Plus, compliance testing includes well over 1,200 individual measurements which, if performed manually, could easily take over a week. The APx solution reduces that time to hours. More importantly, because APx generates the test sequence with all appropriate limits, there is no time wasted on recreating a test methodology or deciphering test requirements. Since Dolby MS11 also supports Dolby Digital Plus, this application note primarily focuses on the MS11 SDK test solution.

A look at the traditional ways of examining out of band noise signals, as well as the advantages of using an ultra-high bandwidth audio analyzer with full 24 bit FFT resolution from DC to beyond 1 MHz.

A look at some of the important features needed in an acoustic audio analyzer, the problems you may encounter in non-ideal testing environment, the needs of good production line testing, and the range of measurements and results that should be produced.

Explains the various ways to view, measure, and manipulate digital metadata, primarily over the HDMI interface.

Serial digital signal analysis is essential in research and development for evaluating audio circuit designs at the chip and at the board level. This AP Applied reviews serial testing procedures, and describes the abilities of the DSIO for APx, as well as the PSIA-2722 for the 2700 Series.

Describes using LabVIEW with APx in a lab or automated production environment. Examples using the APx LabVIEW virtual instrument driver are shown.