Jitter Analysis
Jitter in digital audio systems may cause audible distortion in the form of jitter sidebands in the output signal. Jitter tolerance testing can reveal jitter induced distortion but is often neglected in the design of circuits and components because it is difficult and time consuming. Audio Precision APx analyzers provide jitter generation and jitter analysis features to simplify jitter testing.

Made to Measure for Power Amp Designers
Measure continuous maximum output and peak maximum output automatically, DIM measurements, view power spectrum graphs with a regulated frequency sweep and take other measurements as specified by the CEA-2006 and CEA-490A standards. In addition to conventional balanced common mode rejection measurements, APx555 also enables CMRR measurements in accordance with IEC60268 section 14.15.1.

Code-Free Automation & Complete API
APx500 Measurement Software is the most advanced audio measurement interface available. Complex procedures that include user prompts, limits, and calls to external applications can be created directly in the GUI, saving time and money while ensuring painless updates over time, as no development is required.

Create custom interfaces and application-to-application automation using the comprehensive APx API for integration in VB.NET, C#.NET, MATLAB, and LabVIEW development environments. Projects and automation can be shared with other APx units anywhere in the world.

Common Software Platform
From a practical perspective, all APx audio analyzers use the same software, making tests and results easier to share. All settings for a test are saved in a single project file, making it easy to replicate test setups between R&D and production facilities anywhere in the world. Project files are compatible with all APx instruments and each project is self-contained, so there’s never any worry about dependencies or broken links. Users can even embed waveform files and images within a project file.

For customers, contract manufacturers or management, APx automatically generates rich graphic reports, with highlighted pass / fail limits and options to export as PDF, HTML, Excel, CSV, RTF or MATLAB files.

Digital Protocol Analysis
Modern consumer devices such as televisions, Blu-ray players, and receivers typically use a digital interface such as S/PDIF, Toslink, HDMI to transmit audio signals. In addition to the digital audio data, these interfaces also carry auxiliary information about the audio signal, metadata. The APx Metadata monitors decode and display metadata values as they are received from the device under test.

Advanced Digital I/O (standard)
Provides AES3, AES/EBU balanced digital I/O on XLR; unbalanced SPDIF digital I/O on BNC; and TOSLINK optical digital I/O. The APx ADIO module enables the generation of advanced impairments for sophisticated test of devices via AES/SPDIF/TOSLINK. It also includes the Advanced Master Clock (AMC) module, which handles input and output clock signals for synchronizing an APx with external equipment (or vice versa). AMC also provides jitter generation and measurement functionality for jitter-enabled I/O modules such as ADIO, DSIO and PDM.

ASIO (standard)
PC audio interfaces with installed ASIO drivers appear within the APx500 software as one of APx’s I/O options, with support for up to 16 bidirectional channels. All measurements and test sequences in APx may be used via the ASIO interface, allowing for complete characterization of the connected audio device.

Bluetooth (option)
APx’s 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).

Digital Serial I/O (option)
Digital serial capability is essential in R&D for evaluating designs at the circuit board level. The Digital Serial I/O (DSIO) option provides a direct multichannel connection to chip-level interfaces such as I2S, TDM, and other popular serial interface formats including left-justified, right-justified, and DSP. Jitter capable.

HDMI + ARC (option)
The APx HDMI option allows engineers to measure HDMI audio quality and audio format compatibility on devices such as surround sound receivers, set-top boxes, smartphones, tablets, TVs, and DVD or Blu-ray Disc™ players. APx can stream both lossless and compressed formats from pre-encoded audio test files, making it easy to troubleshoot component compatibility and issues related to downsampling, downmixing, or transcoding.

PDM (option)
The APx PDM option provides direct connectivity for audio devices that have a PDM (pulse density modulation) output such as a MEMS microphone, or an input such as the decimator on a smartphone chip. In addition to standard audio measurements, APx provides variable DC voltage, variable sample rate, and PSR (power supply rejection) measurements for testing devices’ full operating parameters. Jitter capable.

SOFTWARE OPTIONS

APx500 software options provide measurements and functionality beyond the core set of capabilities standard for the APx555. A variety of options are offered, suited to different specific test applications and requirements.

Software options are enabled by one or more “iButtons” that mount on the rear of the APx555. Each iButton enables a particular feature or set of features, and can be moved from analyzer to analyzer as needed.

Electro-Acoustic Production Test (SW-SPK-PT)
The SW-SPK-PT option enables high-speed production test of electro-acoustic devices, providing key loudspeaker measurements in a single one-second sweep. Results include Rub & Buzz detection, essential Thiele-Small parameters, and impedance magnitude and phase. A proprietary modulated noise measurement is also provided to aid in detecting enclosure air leaks.

Electro-Acoustic R&D (SW-SPK-RD)
The SW-SPK-RD option delivers a complete suite of measurements and results tailored to the needs of designers and engineers developing electro-acoustic audio products. It includes key measurements and results such as complete Thiele-Small characterization; time-gated, quasi-anechoic Acoustic Response; Impedance analysis; plus the Loudspeaker Production Test measurements.

POLQA Perceptual Audio Test (SW-POLQA-2)
Perceptual audio measurement returns a subjective assessment of speech quality using the next-generation POLQA algorithm for wide-band speech devices or devices with acoustic coupling. (Successor to PESQ with support for HD Voice, 3G, 4G/LTE and VoIP technologies)

PESQ Perceptual Audio Test (SW-PESQ)
Widely-used, enhanced perceptual measurement for subjective assessment of speech quality on
low-bandwidth devices. (PESQ algorithm)

Speech Transmission Index (SW-STI)
SW-STI is a plug-in for conducting Speech Transmission Index (STI) measurements using the STIPA method.