Máy phân tích âm thanh APx555B

1. Introduction

A culmination of 30 years’ experience making test equipment recognized as the standard of the audio industry, the APx555 is a two-channel audio analyzer without compromise. Developed for R&D engineers and production technicians who need the highest possible performance, a broad range of digital I/O options and fast, intuitive software, the APx555 is the new standard for audio analyzers.

Unprecedented Performance
With a typical residual THD+N of -120 dB and over 1 MHz bandwidth, the APx555 surpasses the analog performance of all other audio analyzers, including a 5 dB improvement compared to our 2700 Series analyzer. Add to this FFTs of 1.2 million points and full 24-bit resolution, and you have performance unmatched by any other instrument.

Maximum Versatility in I/O
APx555 has two balanced and two unbalanced analog inputs and outputs plus 216k digital inputs and outputs via AES/EBU, TOSLINK and SPDIF. Additionally, I/O may be expanded with optional Digital Serial, HDMI with ARC, PDM and Bluetooth modules. A new Advanced Master Clock (AMC) module handles input and output clock signals to synchronize the APx555 with external equipment (or vice versa), and the AMC also enables jitter generation and analysis. AMC is standard with the APx555 and is an option for the APx52x Series and APx58x Series Audio Analyzers.

2. Features

2.1. Multiple Simulaneous Input Types

APx500 software release version 6.0 brings the multi-input capability to APx, allowing engineers to activate a second input type on any APx modular audio analyzer, or APx515 analyzer, and make measurements simultaneously on analog and digital signals. This new capability, paired with the highest channel count and widest range of digital I/O available, provides APx users critical cross-domain insight and the opportunity to reduce testing time. Watch a Multi-Input Demonstration

2.2. Transfer Function

The introduction of v5.0 software added the ability to measure the transfer function of electronic audio and electroacoustic devices. The transfer function measurement provides the complex frequency response function for a device, including the magnitude and phase (or real and imaginary components), using any broadband signal. This feature, a powerful addition to APx software’s Sequence Mode, allows any APx analyzer to be used as a multichannel dynamic signal analyzer or as a so called dual-channel FFT analyzer. With transfer function and any broadband signal, including speech, music, or noise, APx users can now assess the complex frequency response, coherence, and impulse response of their device or system. AP’s transfer function provides gapless and overlapped analysis of multiple acquisitions. It also includes a ground-breaking signal-based triggering that eliminates the need for a pilot tone in open-loop test applications, making it ideal for test of “smart” audio devices.

2.3. Open-Loop Chirp

With release v4.6, APx500 software supports open-loop measurements using the logarithmically-swept sine, or chirp, test signal. This signal provides multiple, high-resolution results in a brief period of time and now APx users can employ the chirp in test scenarios where the signal may originate, or terminate, as a file on the device under test (DUT) or on a server connected to the DUT. This new capability is especially helpful to those developing smart devices (e.g., smart speakers, smartphones).

2.4. 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.

2.5. Code-Free Automation and a 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. Extensive documentation and examples are provided for Visual Basic.NET, C#, MATLAB, LabVIEW, and Python. Projects and automation can be shared with other APx units anywhere in the world.

2.6. Common Software Platform

From a practical perspective, APx audio analyzers use a common software platform, 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 both B Series and Legacy 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 sharing measurement results with 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.

2.7. Made to Measure for Power Amp Designer

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.

2.8. 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.

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