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APx B Series Audio Analyzers and APx500 Audio Measurement Software

 

A versatile, powerful audio test experience!

The APx B Series of audio analyzers represents the state of the art in audio test, with models and options to suit every need from R&D to high-speed production test. Industry-leading analog performance, flexible software with a multi-mode UI, and a wide range of digital I/O and software options make APx the most powerful and versatile series of instruments Audio Precision has ever produced.

More connectivity options with higher performance specifications than any other analyzer in the world!

Every interface option is fully integrated into our software, eliminating uncertainty and enabling faster test setup, while our test software provides unique measurement views and results that are trusted everywhere.

Versatility

Delivering analog, digital and acoustic test capabilities in single instrument, APx500 Series analyzers are the epitome of versatility.

Performance

From the lowest THD+N and crosstalk to the flattest response and widest bandwidth, Audio Precision analyzers are at the forefront of audio measurement.

Connectivity

Beyond traditional analog and digital audio interfaces, AP analyzers offer options for Bluetooth, Digital Serial, HDMI and PDM connectivity. Likewise, AP instruments are designed with automation in mind, supporting (model dependent) LabVIEW, VB.NET, C#.NET, MATLAB, AP Basic or GPIB.

Multichannel

Choose from analyzers with native two-, four-, eight-, or sixteen-channel configurations.

Accredited Calibration

Audio Precision is accredited by A2LA under ISO/IEC 17025:2005, the most stringent standard. Calibration provides documented and traceable verification that instruments meet or exceed all of their published specifications.

 


 

   

Audio Precision Releases APx Software Version 6.1

   
   

Raising the Bar for Rub & Buzz Defect Detection

Major enhancements added in APx500 Software, version 6.1

   
   

BEAVERTON, OREGON, June1, 2021: Audio Precision today released the latest update to APx500 audio measurement software, version 6.1. With this release, AP is adding new measurement results, options, and test signals to establish APx500 software as the best solution for production test of loudspeakers, headphone drivers, and microphones. Most importantly for the designers and manufacturers of speaker drivers, and products incorporating them, APx software now offers the broadest set of methodologies available for detecting rub and buzz defects.

   
   

What is Rub and Buzz

Simply stated, “rub & buzz” is general term commonly used to describe any one of several possible manufacturing defects that cause undesirable noises to be emitted during speaker operation. The most common defect categories are rub, buzz, and air leaks. Rub-related noises occur when the speaker cone is off-center or canted and thus mechanically rubs when it moves to create sound. Buzz defects occur when loose particulate matter—chipped magnet material, bits of glue, etc.—are trapped in the gap between the speaker’s voice coil and the cone. Air leaks are commonly perforations in the speaker surround, imperfectly sealed dust caps, or other unintentional gaps in the housing or cabinet.

Audio Precision Rub and Buzz Measurements

 

As an audible defect in a speaker driver, or device incorporating a speaker, rub & buzz presents several challenges to device manufacturers. First off, it is a subjective issue, with little broad-based agreement on how much is too much – the noises created by a specific defect can be perceived very differently by different listeners. Compounding the issue is the level of distortion in a typical speaker is far greater, and more diverse, than in a typical electronic device and can mask these defects. This latter point means the standard audio measurements of Frequency Response and Distortion will only detect the most severe cases of rub & buzz.

   
   

Rub and Buzz Methods

So, with rub & buzz defects, you have imperfections in a speaker that can negatively impact a listener’s perception of the speaker’s quality, but those defects are not necessarily detectable by traditional audio measurements. To address this issue, several different rub & buzz detection methodologies have been developed within the industry: various approaches using high-pass tracking filters, distortion-oriented methods that focus only on high-order harmonics, and techniques applying human hearing-based algorithms to the distortion signal. While all these methods are applicable to rub & buzz detection, no single method has achieved uniform adoption in the industry.

With the release of APx500 software version 6.1, Audio Precision now offers the broadest set of rub & buzz defect detection methodologies available to speaker designers and manufacturers:

  • Rub & Buzz – Previously available in APx software, this method uses high-pass tracking filters to remove the fundamental signal and detect defects as excursions in the residual waveform’s crest factor or peak ratio.
  • SoneTrac (new with v6.1) – A Bose-developed improvement to the aforementioned Rub & Buzz, this method filters the residual signal and ratios it to the RMS of the total signal to reduce the noisiness of the measurement result.
  • High-Order Harmonic Distortion (HOHD; new with v6.1) – A classic method for rub & buzz detection, HOHD uses the THD (Total Harmonic Distortion) ratio but only of harmonics above the 10th, 10-35, 20-200, etc., which is a simple way to account for frequency masking effects.
  • Rub & Buzz Loudness (new with v6.1) – Applies a psycho-acoustic loudness model to the residual signal to calculate the perceived level of the rub and buzz based on well-established models of the human perception of sound
   
   

New Stimulus Signal - Fast Sweep

To support the addition of the HOHD and Rub & Buzz Loudness measurements, AP is introducing the Fast Sweep signal with APx500 release version 6.1. Fast Sweep, as its name implies, is an extremely fast stepped frequency sweep with no input or output ranging between steps, continuous transition between steps to minimize transient effects, and has a total sweep time that rivals the speed of a logarithmically-swept sine (chirp) signal. A few of the advantages of the Fast Sweep are the lack of transient ripples at low or high frequencies, the ability to sweep from low-to-high or high-to-low frequency, the support for measuring harmonics above the 20th, and precise control of the number of discrete points used in measurements.

   
   

Additional New Features

In addition to the expanded selection of rub & buzz methods, as well as the new Fast Sweep stimulus, APx500 release version 6.1 now allows users to switch instantly between IEC and IEEE THD calculation modes for harmonic distortion results. Version 6.1 also adds the ability to normalize harmonic distortion results, addressing common measurement artifacts that occur when testing loudspeakers. Users can now also save all acquired waveform, impulse response, or cross-correlations results to .wav files, and this function can be included as a sequence step in automated measurement sequences.

“While version 6.1 is officially a minor release, and thus a free upgrade to any analyzer licensed for version 6.0, it delivers significant, new capabilities, especially for those involved in the design, manufacture, and test of speaker drivers and any product incorporating them,” said Daniel Knighten, Audio Precision General Manager. “Simply put, APx audio measurement software now offers the broadest set of rub & buzz defect detection methodologies available.”

   
   

APx500 Version 6.0 & Software Licensing

With this latest release, new APx audio analyzers will begin shipping with version 6.1 software. Each new analyzer also includes one year of software maintenance, effectively licensing that instrument for APx version 7.0 when it is released (as well as any minor 6.x releases that occur prior to v7.0). Release v6.1 is a no-cost upgrade for any analyzer licensed for version 6.0 and users need only download v6.1 from AP.com.

Software upgrades are available for owners of Legacy APx analyzers, with options for upgrading from v4.x (or earlier) to v5.0, from v4.x to 6.0, and v5.0 to v6.0. Software maintenance contracts are available for instruments licensed for the current release (v6.0), entitling the analyzer to one, three, or five additional major software releases depending upon the contract purchased.

Release 6.1 is compatible with all analyzers in the APx500 Series. An APx KeyBox is required to run v6.1 on Legacy APx analyzers. APx KeyBoxes already installed on Legacy analyzers (for v4.6 and 5.0), are also compatible with v6.1 and only require an updated license file once an upgrade is purchased.

Read "What's New: APx500 version 6.1.0 June 2021"

   

 


Audio Precision APx555 B Series

The APx555 is the new standard in high-performance audio analyzers for R&D engineers and production technicians. With typical THD+N at –120 dB, its analog performance surpasses even that of the classic 2700 Series.

  • Available options
    • HDMI (with ARC): The finest HDMI audio analyzer in the world. Ideal for Dolby / dts compliance testing.
    • Digital Serial I/O: 8 channels, oscilloscope monitor, independent clocks, automatic rate calculators and active timing diagrams.
    • Bluetooth®: The best solution in the world for testing Bluetooth audio on smartphones, tablets, and other devices.
    • PDM: Complete solution for testing 1-bit oversampled audio in MEMS microphones and DSD audio systems.

Audio Precision APx5550 B Series audio analyser front 3-4

 

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Datasheet

 


Audio Precision APx525x B Series

The APx52x Series is the ideal balance of analog performance and breadth of digital I/O for R&D engineers and production technicians.

  • Available options
    • BW52: One million point FFTs, DC to 1 MHz bandwidth and full 24-bit resolution.
    • AG52: Exceptionally clean square waves and improved analog performance.
    • HDMI (with ARC): The finest HDMI audio analyzer in the world. Ideal for Dolby / dts compliance testing (APx525 only).
    • Digital Serial I/O: 8 channels, oscilloscope monitor, independent clocks, automatic rate calculators and active timing diagrams (APx525 and APx526 only).
    • Bluetooth®: The best solution in the world for testing Bluetooth audio on smartphones, tablets, and other devices.
    • PDM: Complete solution for testing 1-bit oversampled audio in MEMS microphones and DSD audio system
  • Available models
    • APx525: 2 channel analog plus 192K digital.
    • APx526: 4 channel analog plus 192K digital.
APx525 Audio Analyser front 3-4
APx526 Audio Analyser front 3-4


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Datasheet


 

Audio Precision APx58x B Series

The APx58x Series are true multichannel audio analyzers, with 8 or 16 simultaneous analog outputs and inputs as well as 192k digital. With the optional HDMI and Digital Serial I/O options, there is no better analyzer in the world for testing HD and Blu-ray devices.

  • Available options
    • HDMI (with ARC): The finest HDMI audio analyzer in the world. Ideal for Dolby / dts compliance testing (APx585 only).
    • Digital Serial I/O: 8 channels, oscilloscope monitor, independent clocks, automatic rate calculators and active timing diagrams.
    • Bluetooth®: The best solution in the world for testing Bluetooth audio on smartphones, tablets, and other devices (APx585 only).
    • PDM: Complete solution for testing 1-bit oversampled audio in MEMS microphones and DSD audio systems.
  • Available models
    • APx585: 8 channel analog plus 192k digital.
    • APx586: 16 channel analog plus 192k digital.

 

 

 

APx582 Audio Analayser front 3-4 APx585 Audio Analyser front 3-4 APx586 Audio Analyser front 3-4

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  Datasheet  


Audio Precision APx515 B Series

The APx515 is a performance audio analyzer optimized for production test. It is a best-in-class instrument for its speed, performance, automation and ease-of-use.

  • Available options
    • SW-ACR: Adds acoustic response measurements.
    • SW-AML: Adds IMD, MOL, dynamic range, FFTs and other advanced measurements.
    • SW-HST: Adds high speed multitone and continuous sweep measurements.
    • SWB-2: Includes all ACR, AML, and HST measurements, plus 2 simultaneous channels of ASIO connectivity
APx515 Audio Analuser front 3-4

APx515 datasheet thumb 

Datasheet  



Audio Precision APx517 B Series

The APx517B is an integrated acoustic test system, complete with audio analyzer, power amplifier, headphone amplifier, and microphone power supply, along with an array of digital interface options.

 

Learn More

 

APx517B Acoustic Analyser front 3-4

  

 

Audio Precision 2700 Series

DEPLETED SUPPLY

The 2700 Series is now longer available.

Please contact us to discuss replacement products appropriate for your application. The closest replacement products in the Audio Precision portfolio are the B Series APx555 or the B Series APx525 analyzers.

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2700 Series Audio Analyser front 3-4

 

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 APx555 v 2700 series Comparison


APx500 v 4.0 - Bench Mode capabilities