FFT Spectrum Analysis, Averaging | SRS Labs SR785 guide

SR785 Two Channel Dynamic Signal Analyzer

FFT Spectrum Analysis

The SR785 Two Channel Dynamic Signal Analyzer is a precision, full-featured signal analyzer that offers state-of-the-art performance and a wide selection of features at a price that's less than half that of competitive analyzers. Building on its predecessor, the SR780, the SR785 incorporates new firmware and hardware that make it the ideal instrument for analyzing both mechanical and electrical systems. Whether your measurements involve modal analysis, machinery diagnostics, vibration testing, servo systems, control systems, or acoustics, the SR785 has the features and specifications to get the job done. Standard measurement groups include FFT, order tracking, octave, swept-sine, correlation, time capture and time/histogram. The SR785 brings the power of several instruments to your application – a spectrum analyzer, network analyzer, vibration analyzer, octave analyzer and oscilloscope.

A unique measurement architecture allows the SR785 to function as a typical dual channel analyzer with measure- ments like cross spectrum, frequency response, coherence, etc. Alternatively, the instrument can be configured so that each input channel functions as a single channel analyzer with its own span, center frequency, resolution, and averaging.

This allows you to view a wideband spectrum and simultaneously zoom in on spectral details.

The same advanced architecture provides storage of all measurement building blocks and averaging modes. Vector averaged, RMS averaged, unaveraged and peak hold versions of all measurements are simultaneously acquired and can be displayed without re-taking data.

Use the SR785 to monitor the fundamental and harmonics of your signal. Total harmonic power and THD are calculated in real-time for fast, accurate analysis.

Bottom display shows a wideband FFT, while the top display shows a narrowband FFT of the same signal. The sideband marker has been selected for calculation of the total sideband power.

Averaging

The SR785 comes equipped with a wide selection of averaging techniques to improve your signal to noise ratio. Choose RMS averaging to reduce signal fluctuations, vector averaging to actually eliminate noise from synchronous signals, or peak hold averaging. In the order-tracking measurement group, time averaging is available. Both linear and exponential averaging are provided for each mode.

The SR785 is so fast, there's no need for a separate "fast averaging" mode. Averaging is always fast, and the display update rate is never sacrificed to increase the averaging rate. For instance, in a full span FFT measurement with a 4 ms

SR785 specifications

The SRS Labs SR785 is a powerful and versatile audio analysis tool designed for audio engineers, researchers, and manufacturers. This instrument is renowned for its ability to perform a wide array of measurements, making it an essential asset for anyone involved in audio testing and development. With its cutting-edge features and technologies, the SR785 stands out in the competitive field of audio analysis.

One of the main features of the SR785 is its dual-channel capability, which allows users to analyze both input and output signals simultaneously. This is particularly useful for applications such as loudspeaker testing, where comparing the input signal against the output can provide valuable insights into the performance and fidelity of audio systems. The device supports a wide dynamic range and can capture audio signals from an impressive range of frequencies, ensuring accurate representations of even the most nuanced sounds.

The SR785 employs state-of-the-art Fast Fourier Transform (FFT) technology, enabling users to switch between time-domain and frequency-domain analysis with ease. This flexibility allows engineers to tailor their measurements based on specific requirements, whether they are evaluating distortion levels, frequency response, or impulse response. The instrument’s high-resolution display provides clear visual representations of the analyzed data, making it easier to identify trends and anomalies.

Another notable feature of the SR785 is its built-in automation capabilities. This technology allows for automated testing sequences, streamlining the analysis process and reducing the potential for human error. Users can pre-program a series of tests to run automatically, ensuring consistency in measurements and saving valuable time during testing and analysis.

Additionally, the SR785 offers extensive data storage options, allowing users to save measurement results for future reference or comparison. This is particularly beneficial for long-term studies or for manufacturers conducting quality control checks on production lines. The device is also equipped with a range of connectivity options, including USB and GPIB, facilitating easy integration into existing test setups and enhancing its versatility.

The combination of advanced features, robust technologies, and user-friendly design makes the SRS Labs SR785 a top choice for audio professionals seeking a reliable and efficient audio analysis solution. Whether for research, development, or quality assurance, the SR785 delivers precise and actionable insights that drive sound performance to new heights.