AP - The Recognized Standard In Audio Test

APx515 Audio AnalyzerHOME/PRODUCTS/APx SERIES/APx515

2-Channel Audio Analyzer

Ideal for production test and entry-level R&D applications.


The APx515 is a high performance audio analyzer optimized for production test. APx515 has a typical THD+N of –106 dB, a 1.2M point FFT with 24-bit resolution, and up to 216k digital I/O. It is a best-in-class instrument for its combination of speed, performance, automation, and ease-of-use.

APx515 is a significant product because it delivers the performance and reliability of Audio Precision at a production-level price.

APx is the fastest audio analyzer in the world, returning 21 audio measurements in as fast as 1.2 seconds. It is also the easiest to use, with one-click measurements, custom reporting and sophisticated automation without any programming. A full API and LabVIEW driver is also provided.

This speed and ease-of-use means test will never be a bottleneck, and production line managers can achieve reliable, consistent results compared to the current low-cost alternatives like a distortion analyzer.

For companies outsourcing their production, requiring APx515 on the production line gives tighter control over production, ensuring manufacturers are meeting their contractual requirements.

Easy automation delivers comprehensive test in 3 seconds.

APx515 operates either as a stand-alone test unit with its own user interface or it can be controlled by a master .NET, MATLAB, or LabVIEW application. In either case, an operator can control APx with a keyboard, foot controller or barcode scanner, or the system can be totally automated. Switchers and external devices such as pass/fail lights are also supported.

In stand-alone mode, sophisticated test sequences are created by selecting from a list of common audio measurements—no coding required. Pass/fail limits, advanced configurations and user prompts can be added as necessary, then the type of report is selected—rich graphic prints using Microsoft Word or export to CSV. The project can be locked to prevent accidental changes once on the production line.

On an automated line, the master .NET, MATLAB, or LabVIEW application can control the APx515 directly using the API or APx LabVIEW driver. Individual measurements can be made or the master application can call a test sequence created with the APx UI.

Download the AP Applied on Production Test to learn more about how the APx515 is the ideal solution.

AP Applied: Production Test

Key features

High performance

  • -106 dB typical residual THD+N (1 kHz, 2.0 V)
  • Up to 216k digital connectivity
  • Comprehensive test in 3 seconds

Easy automation

  • Automation without a single line of code with Sequencer
  • VB.NET, C#.NET, MATLAB, and LabVIEW support in API
  • Read more ...

Software options expand capabilities

The APx515 ships with standard measurements included. Software options allow the APx515 to perform more advanced measurements as needed. Note: if you must use a version of APx500 Measurement Software earlier than v3.2, please read this notice.

  • SW-BEN: Enables use of Bench Mode on the APx515, providing real-time visibility into device behavior across a variety of parameters. See the APx500 Software page for more information.
  • SW-AML: Advanced Measurement Library option adds IMD, dynamic range, bandpass level, FFT power spectrum, digital metadata, regulated frequency sweep, digital error rate, and maximum output power measurements.
  • SW-HST: High Speed Test option adds continuous sweep and multitone analysis.
  • SW-ACR: Acoustic Response option adds energy-time curve, impulse response, frequency response, phase response, and distortion vs. frequency of acoustic devices using a time gated exponentially swept sine wave.
  • SW-SPK-RD: Speaker test option for R&D includes SW-ACR plus complete Thiele/Small characterization, Rub & Buzz, Modulated Noise Air Leak detection, Polar and CSD plots, and Loudspeaker Production Test.
  • SW-SPK-PT: Loudspeaker production test for complete performance evaluation using a 1–second sweep; Polarity, Rub & Buzz, Modulated Noise Air Leak detection, Distortion Product Level and Ratio, and Golden Unit comparison.
  • SW-ASIO: 2 channels of direct ASIO connectivity for evaluation of PC interfaces.
  • SW-POLQA2: 2 channels of POLQA perceptual audio test.
  • SW-PESQ: 2 channels of PESQ perceptual audio test.

Option Bundles

Popular combinations of measurements for APx515 that are convenient and cost-effective.



Ideal for testing

APx515 is an excellent choice for most 2-channel analog and digital production test applications.

  • Power amps
  • Automotive head units
  • MP3 players
  • CD / DVD players
  • Televisions
  • Digital interfaces
  • Broadcast equipment
  • Facility service





Download full specifications

  • Residual THD+N (20 kHz BW)
    –102 dB + 1.4 µV
    Typical <–106 dB (1 kHz, 2.0 V)
  • Sine Frequency Range
    2 Hz to 80.1 kHz
  • Frequency Accuracy
    3 ppm
  • IMD Test Signals
  • Maximum Amplitude (balanced)
    16.00 Vrms
  • Amplitude Accuracy
    ±0.05 dB
  • Flatness (5 Hz–20 kHz)
    ±0.010 dB
  • Analog Output Configurations
    unbalanced, balanced, common mode
  • Digital Output Sampling Rate
    27 kS/s to 200 kS/s
    27 kS/s to 108 kS/s Optical
  • Dolby / dts Generator
    Yes (encoded file)
  • Maximum Rated Input Voltage
    125 Vpk
  • Maximum Bandwidth
    >90 kHz
  • IMD Measurement Capability
  • Amplitude Accuracy (1 kHz)
    ±0.05 dB
  • Amplitude Flatness (10 Hz–20 kHz)
    ±0.010 dB
  • Residual Input Noise (20 kHz BW)
    ≤1.4 µV
  • Individual Harmonic Analyzer
  • Max FFT Length
    1248K points
  • DC Voltage Measurement

    (Included with all APx515 instruments)
  • Level & Gain
  • Frequency Response
  • THD+N
  • Signal to Noise Ratio
  • Noise
  • Crosstalk
  • Interchannel Phase
  • DC Level
  • Frequency Measurement
  • Measurement Recorder
  • Stepped Level Sweep
  • Stepped Frequency Sweep
  • CMRR
  • Pass/Fail
  • Scope Montior
  • DC Level Sweep
  • Q-peak Noise
  • Level Ratio
  • Input Sample Rate
    (Software option SW-AML)
  • FFT Spectrum Analyzer
  • IMD (DFD/MOD/SMPTE/CCIF) Level Sweep
  • IMD Frequency Sweep
  • Dynamic Range (AES17)
  • Bandpass Level
  • Bandpass Level Sweep
  • Bandpass Frequency Sweep
  • Crosstalk Sweep, Custom
  • Crosstalk Sweep, One Channel Driven
  • Crosstalk Sweep, One Channel Undriven
  • Regulated Frequency Sweep
  • Digital Error Rate
  • Maximum Output Level
  • Maximum Output Level (Burst)
  • Metadata Recorder
  • Noise Recorder
    (Software option SW-HST)
  • Continuous Sweep
  • Multitone Analyzer
    (Software option SW-ACR)
  • Acoustic Response Measurement
    (Software option SWB-2)
  • Includes all measurements from SW-AML, SW-HST and SW-ACR
  • Adds ASIO interface, 2 simultaneous channels

  • PC with 2 GHz or faster multi-core processor (2 or more cores)
    Note: the Intel Atom dual-core processor does not have sufficient performance to run APx software.
  • 2 GB or more RAM (4 GB or more recommended for Windows 7/8).
  • Microsoft Windows XP (32-bit, SP 2 or later), Windows Vista (32-bit), Windows 7 (32- or 64-bit), Windows 8 (32- or 64-bit).
  • More detailed information is available on our
    AP Software and Windows Compatibility chart
  • Download System Requirements Document
  • System performance is sensitive to processor speed; faster processors will yield faster results.
  • APx500 is data intensive and it is recommended that other data-intensive applications not be run concurrently. This includes Audio Precision AP2700, APWIN or ATS.
  • We recommend and support the following specific editions of Microsoft Windows: XP Professional SP2 and SP3, Vista Business and Ultimate, Windows 7 Professional and Ultimate (32- and 64- bit), Windows 8 Pro and Enterprise (32- and 64-bit).

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